Week 36: Review

As has been the case for the last little while, things have been crazy busy this week so getting everything in has been a challenge. On the running front, I had to move things around a bit, but I did manage to squeeze in pretty much all that was planned. I did have to chop a mile off of a couple of mid-week runs, but other than that I managed to get things in at the appropriate pacing. Regardless, I did manage to click over the 1000 mile mark for the year on Sunday :D

Sunday's 18 miler was a bit on the warm side, but fortunately not nearly as bad as it was just a few weeks ago. The cool weather we've been getting lately has spoiled me a bit, as running and biking with the temperatures in the teens is so much nicer than the hot and humid we've been enduring lately. On the upside, I was able to pace myself a little better than last week - averaging a 4:45/km pace rather than 4:33. Looking back at the telemetry, I was pretty much bang on the 5:00/km target until the half-marathon mark when I picked it up a bit. I tend to have a bit of a backwards pacing instinct - the more fatigued my legs become, the faster they seem to want to go :P

Like last week, this long run was done with my Garmin rather than the Polar. After transferring my telemetry from Friday's 5 miler I noticed a (nearly inaudible) hissing noise coming from the unit. To be safe, I've pulled the (new) battery out of the unit and contacted their support department to get guidance on what to do about these symptoms. Searching over their fora, there were a few mentions of similar symptoms but as those were covered under warantee (they all came from the factory this way) there isn't much detail on what was wrong (they sent it in, it came back fixed).

Other than the sound, the unit is working flawlessly so I don't think it's anything major. Looking at the unit I think one of the battery pins isn't quite contacting the side of the battery, and the gap is small enough that it's arcing. I'm not sure if it's a matter of the new battery being a little smaller than it's supposed to be, or if the pin has gotten bent back a bit, but if it is either one of those issues it should be a relatively simple fix. With that said, the way that products are made nowadays even simple things can end up being complex to actually repair.

On the cycling front, myself and a couple of guys from the group managed to get together on labour day for a short 50K. Tried to talk them into something a bit longer, but unfortunately they haven't been out a lot lately so they wanted to start back carefully. Either way, we headed out just before 8am and while it was a bit chilly (11C), once we got moving that was quite comfortable. It ended up being a good thing we kept it short, however, as it started pouring rain for the last couple of minutes ;)

Other commitments meant that Saturday's ride had to be cut down to 55K, and Friday's to 30K. Wednesday's ride didn't happen due to weather, so my net cycling mileage this week is pretty pathetic. Either way, not much that can be done about that as none of those constraints were particularly mutable.

On the upside, the pools have finally switched back over to the fall/winter schedules so I don't need to try and shoehorn two hours work of work into 90 minutes. My normal pool was unfortunately down for maintenance this week, but another close by facility has a nice three hour session available so that helped. While I shortened the sets a bit given the reduced time constraints, I kept them at moderate distances (1.5-2K) in order to squeeze in a bit more distance than normal. I'll see how this holds out, and if it goes well it should help me to continue improving.

Week 36 Totals:
Running: 54.7km (34.0mi)
Walking: 2.4km (1.5mi)
Cycling: 135.2km (84.0mi)
Swimming: 9.0km (5.6mi)
Total: 201.3km (125.1mi)

Year to Date:
Running: 1612.5km (1002.0mi)
Walking: 77.6km (48.2mi)
Cycling: 3531.0km (2194.1mi)
Swimming: 235.1km (146.1mi)
Total: 5456.2km (3390.3mi)

The next couple of weeks are likely to be even busier than it has been, as the dedication for our new church is happening on the 23rd and I'm taking care of photographically documenting the associated events. I've been recording the entire construction process from the start, but the final preparations mean that the changes are coming fast and furious and it's a lot more work. With the workers scrambling to get everything done in time, the schedule is somewhat dynamic and planning around it is a bit more difficult than normal.

The side effect of this is that I'm going to have to skip the Lakeside Olympic triathlon next weekend that I wanted to do. Next weekend is looking pretty packed with preparations, and heading out of town for something like that would be difficult to fit it. As that's the last race of the year around these parts, that pretty much means that I'm not actually going to be able to fit a triathlon in this season. Unfortunate, but I've enjoyed the training either way and made improvements that should form a solid base for next year's more ambitious targets.

Week 40: Review

It's nearly been a year since I ran my first half marathon, and reading over the many posts from others running this year's Scotiabank races brings back a lot of good memories. I had initially intended to run the half again this year as a tune-up race for the full at the Goodlife Marathon in mid-October. Unfortunately, the injury messed up those plans so I didn't get to head out and race this morning.

Either way, sports injuries are part of the equation in any running schedule and learning to work around problems is an important lesson along the way. As annoying of a speed bump as it was, it only took a couple of weeks to clear up so I am thankful that it didn't end up being something more serious. I did lose some fitness between the downtime itself and having to be careful building back up, however I'm still in relatively good shape so it's just a minor setback. If it wasn't for the close proximity to the race itself, it likely would have just slowed me down a bit.

While my intention to get my marathon time down to 3:20 didn't pan out, I did manage to get a Triathlon in despite the problems and that will form an important foundation for my base training over the winter. After this morning's 10 miler, my heart rate is beginning to fall back into the normal range so the fitness is comming back. If it continues along this trajectory, I'm hoping to be able to race the half marathon in October's race and potentially put the summer's training to use there as well.


Getting back to the point, the running sessions this week went quite well. I'm starting to add speedwork back into the equation, and ended up bumping my long run this morning to about 10 miles. While the heart rates are still higher than I'd like for my normal paces, they are coming down so I'm getting back into the swing of things. I might give a short tempo run a shot this week to see how that goes, however I'll have to play it by ear.

I did have a few annoyances with the footpod cutting out on me this week, but after a bit of testing it appears that it's just the battery going on me prematurely. I've had a few issues on and off since I replaced it last month, so it's likely just a matter of a cell that was sitting on the shelf for too long and was depleted to start with. I'll have to head out and look for a replacement, although given this experience I'm likely going to be looking for a better shop to buy them from in the future.

Cycling-wise, I only ended up getting one session in on Friday due to weather. That ride was also a bit shorter than planned (50K vs. 80K) due to scheduling issues, but the weather was great so it was an enjoyable ride nonetheless. This coming week looks like it's going to be a bit dodgy as well, but I'm going to have to focus on working around it a little better so that I can at least get in two decent rides.

With respect to swimming, I managed to get my two sessions in as planned. On Tuesday I did a number of 750m sets, and on Thursday I did two 750s and a 1000m set to keep myself comfortable with longer distances. Fortunately, thanks to Melanie I managed to find a decent Triathlon swimming clinic and will be starting it tomorrow evening. I missed the first session at this point, but there are still nine weeks left so there is plenty of instruction left. The swim is by far my weakest discipline, and an opportunity like this to improve my technique will likely do me more good than anything else.

Week 40 Totals:
Running: 48.3km (30.0mi)
Walking: 3.5km (2.2mi)
Cycling: 50.2km (31.2mi)
Swimming: 6.7km (4.2mi)
Total: 108.7km (67.5mi)

Year to Date:
Running: 1,948.9km (1,211.0mi)
Walking: 202.4km (125.8mi)
Cycling: 3,172.2km (1,971.1mi)
Swimming: 59.9km (37.2mi)
Total: 5,383.4km (3,345.1mi)

As noted above, this week is likely to be pretty unstable in the weather department so I may need to move things around a bit. I've got a tentative plan lined up, but it's going to depend on when I can get those cycling sessions in. I'm also flirting with replacing Tuesday's speedwork with a tempo run to test out the legs, but I'll have to see how I feel at that point.

Mon 50K Ride, Swim Clinic
Tue 2mi Swim, 5mi Recovery w/6x100m
Wed 30K Ride (if weather permits), 10K Recovery
Thurs 2.5mi Swim, 6mi GA
Fri 50K Ride
Sat 4mi Recovery, 80K Ride
Sun 11mi (17.7K) LSD

Lakeside II: Race Report

After getting all of my gear ready last night, I got up at 5:30 this morning in order to get down to the race site by 8:00am. The race itself started at 10:00, but there is a lot to set up for a Triathlon and seeing as this was my first I wanted to be doubly sure that everything was in order. Looking at the thermostat, it was 3C when we headed out so it looked like it would be a cool day. I put on my race clothes and then put another layer on top to keep me warm until the race and headed out the door.

Most of my race equipment (aside from the wetsuit and bike) while I was taking inventory the night before. A lot more stuff to worry about than when getting ready for a running race.

We made a few wrong turns on the way, but we still managed to get up there shortly before 8am. I unpacked my stuff and headed towards the race site. Fortunately, the registration tent was already open (it wasn't scheduled to open until 8:15) so I got all of my stuff and headed over to transition. The racks were assigned by bib number, but fortunately few people were there this early so I had my choice of spots on that rack and grabbed the one on the edge closest to the bike exit.

After racking my bike and setting up my transition area, I walked around the various aspects of the start/finish lines to familiarize myself with the layout. It was pretty straightforward, and as my rack was right near the edge of the transition area it was easy to spot from a distance. I took a closer look at the maps they had of the swim, bike and run routes to familiarize myself with the details then headed back to transition to watch my stuff.

Things started filling up quickly after that, so I looked around to see how others were setting things up for any potential ideas. It was still too early to put on the wetsuit, as while it was cool it wasn't cold enough that that would be comfortable outside of the water. As such, I just relaxed and took in the atmosphere to help get the mind ready for the race that was coming.

About 30 minutes before the start, I put on and adjusted the wetsuit just before the organizer's started the pre-race briefing. After hearing them out, I headed over the beach to do some warm ups and familiarize myself with swimming in the wetsuit. I was a bit worried as I hadn't had an opportunity to test it out before the race, but it worked quite well right off the bat and I was able to comfortably do a few 100m sets. As the wave 1 start approached, I headed back into the shallow water to get out of the way. I stood around nervously for a bit, checking all of my equipment and going through my plan for the rest of the race.

After a quick announcement, the starter's horn was sounded and the first wave was off. As the second wave moved forward to the start line, I possitioned myself in the middle of the pack. On the inside edge I was worried about having too much traffic, but on the outside I was concerned about drifting off of the line so I figured that I'd split the difference. The plan was to keep a relatively comfortable pace and not worry too much about pushing it, as this was my weakest discipline and I didn't want to burn myself out.

Swim (600m) - 13:39 - 2:17/100m

Three minutes later our horn sounded and we were off with arms and legs flailing everywhere. After about 30 seconds, it was evident that it would be extremely difficult to maintain a rhythm as there were bodies in pretty much every direction. Every time I was hit or I bumped into someone else, it through off my routine and it became difficult to keep my breathing under control. I eventually managed to push my way out of the main mass and had a bit of a repreive, but I had to push to do that so I was a bit more tired than expected.

When we hit the first bouy, things started getting crowded again so I took a wide line to try and avoid that. It worked well, however it also meant that I was covering more distance than I would have if I'd taken the corner directly. Either way, I took this leg a little slower to get my breathing back under control but it was still difficult. After hitting the second bouy I managed to start getting into a decent pattern again and pushed my way into the shore.

As we got close, people started standing and running. While I knew that I'd be faster if I kept swimming, I was pretty tired at this point so I just got up as well and ran the rest of the way in. Once I got into ankle deep water I unfastened the zipper on my wetsuit and removed the top half while I ran toward my transition station. Fortunately, other than a little trouble finding the pull cord on the first try it came off quite easily before my feet were out of the water so I could focus on the rest of my transition.

T1 (Swim to Bike) - 3:11

When I hit my transition station I removed the lower half of the wetsuit and set it down on the back edge of the towel I had set up. Fortunately, other than a bit of leakage around the neck it has mostly kept my clothes dry so I was in good condition for the next leg. The next step was to get my socks and cycling shoes on, and it's evident that the socks were not a good idea. Trying to get wet feet into socks with nowhere to sit down and nothing to lean on was a clumbsy process and took a good deal of time. After getting the left foot on, I just sat down on the ground to get the right one on as there was no sense in wasting more time.

Once that was ready, I quickly grabbed my race number, watch and sunglasses, then put on and fastened my helmet. I then unracked my bike and ran to the bike start line. I was expecting this to be a bit of a problem, as cleated cycling shoes aren't exactly designed for running on. Fortunately, most of the path to the mounting line was grass and dirt so it wasn't much of a problem. I was able to pass the line, clip in and get off within a matter of seconds.

As noted above, 3:11 is a pretty pitful transition time so this is something that I'm definately going to need to work on. The socks were naturally the biggest problem here, so the next time around I'm going to have to bite the bullet and see if I can pull it off without them. Naturally, it saves a lot of time but I was a bit concerned about getting blisters in the process.

Bike (20km) - 39:04 - 30.7km/h

The bike ride was probably the most enjoyable leg of the race, as the legs were still fresh and I was able to fly past a lot of people in the process which did a lot to boost my confidence. The route was a relatively pleasant one, with only a handful of very small hills to deal with. When I had decent openings I was able to maintain 35km/h paces on the flats and there wasn't really any wind to deal with either.

The tricky part, however, were the passing rules in this leg of the race. Due to the size of the drafting area we aren't allowed to remain in for more than 15 seconds, there were basically only two lanes to work with. On the flat straight segments it wasn't much of a problem, however on uphill and downhill segments lots of people were passing others, so the passing lane was full. In order to avoid getting within the 5m no-drafting zone behind them, that meant that I had to apply the breaks a lot (bleeding off energy) until I could get an opening.

Either way, there isn't really much that could be done about this given the structure of the race. The solution, naturally, is simply for me to get better at the swim and T1 stages so that I can start the bike leg sooner and get out ahead of the traffic ;)

T2 (Bike to Run) - 1:48

At the end of this leg, I dismounted at the line and ran the bike back to the rack. After securing it on the rack, I quickly popped off my helmet and cycling shoes and put on my running shoes. I lost a bit of time here as I elected to use conventional shoelaces and had to tie them, but aside from that everything else went quite smoothly here. There were a few things I could have streamlined a little (eg changing shoes before helmet, so it isn't in the way) but the main improvement I need to make here is getting used to elastic laces.

Run (4K) - 19:58 - 5:00/km

When I hit the run segment, I wasn't really sure how the previous two legs would effect me so I elected to take it conservatively. I've run a 5K race at a 4:11/km pace, and could probably pull out a sub-4 pace over a 4K course, but whether that would be possible after the bike and swim was up in the air. Additionally, due to my time off from injury my heart rate has been a bit higher than normal, and a nagging cold has pushed it up a bit as well so I wasn't sure how a full-blown VO2Max effort would last.

Furthering the complexity of the situation, I made a significant tactical error with my RS800 HRM. I had switched it on at the begining of the bike segment to get heart rate and elevation for the ride, and configured it to also record speed from the footpod. Naturally, on the bike the footpod wouldn't be in range so nothing would be recorded, but I assumed that it would pick it up once I got back and started running. Unfortunately, this wasn't the case as the watch had obviously given up on connecting to the footpod (ie I should have stopped the first workout and started a new one). As such, when I hit the run I had no readout of my pace or distance, and simply had my HR to work with.

As such, when it became obvious that I only had heart rate to work with I elected to not worry about it too much and just take it easy. I caught up to another runner who was going at a comfortable pace and stuck with him for a while. Unfortunately, part way through the second kilometer he started to slow down significantly so I had to drop him and head out on my own. At this point, I was accelerating a bit and felt good so I let myself speed up a bit more. I hit the turnaround point and began heading back.

As I approached the resort, I realized that I only had about 500m left so I figured that I'd open up and see what was left in the tank. As I accelerated I realized that there was plenty left in the tank so I stepped up to a full sprint passing a handful of people. I had to slow down a bit on the final turn as it was narrow and I had to navigate around another fellow, but once I got into the final stretch I gave it everything and flew over the finish line.

It was obvious at this point that I could have easily run a lot faster for most of the run, but until I got to the end I wasn't sure how well my body would have taken it so I played it a bit too cautiously. Naturally, not having my normal pacing information made it even more difficult, as I had to base my targetting off of heart rate which is a little off-kilter at this point. Either way, this is part of the learning process and I'll know next time that the fatigue isn't quite as bad as I thought it would be.

Gun time: 1:17:37 (overall results)
Swim: 13:39 (156/265)
Bike: 39:04 (53/265)
Run: 19:58 (58/265)
Place overall: 88/265 (66.8 percentile)
Place in age group: 6/18 (66.7 percentile)


Regardless of all of that, the race today was an excellent experience and I hope the first of many more. There were a lot of lessons learned here and, by extension, a lot of room to improve. Primarily, I should be able to comfortably shave a couple of minutes off of my transitions (largely because they were so brutal this time around) which is a heck of a lot easier than gaining that much time in any of the three sports.

Naturally, my swimming also has a lot of room for improvement so I'll have to do some work on that. While I've largely got the physical aspects of it in place at this point, I need to work more on technique so that I'm not so easily thrown off by outside influences. I should also try and get some more practice in open water, but that's difficult to do in the off season so that might have to wait a bit.

Taste of Spring...

The weather lately has been as close to perfect as it gets around here, and yesterday was no exception to that. A light breeze, 13C temperatures and bone dry pathways are a refreshing break after the winter that we've gone through this year. Spring doesn't officially start until Friday, however this is generally the best time of year as it hasn't really gotten hot yet, but it's still warm enough to head out without all of the gear that the winter entails ;)

As such, shortly after 4PM I headed out for the first time this year with a pair of shorts and a t-shirt. Aside from feeling great in and of itself, the weather also prompted many other people to head out as well. As such, there were tons of people out on their bikes, dozens of other runners just getting back into the routine after taking the winter off and children playing all over the place. It's certainly nice to see things livening up again, as most of my courses can get pretty quiet when the weather gets cold ;)

Unfortunately, my footpod battery died on me as I was starting but given the weather I just ignored it and headed out anyway. This did make things a little more difficult, as the plan called for a 7 mile run with 6x100m strides. I normally do the strides going back and forth down a straight ~2.5km stretch of road, so gauging my overall distance can be difficult without electronic aides. Fortunately, with only six of them scheduled I figured out a way to work them into a different route that I knew reasonably well and could guestimate distances. Naturally, figuring out exactly how long 100 meters is by feel is a bit difficult, so I simply counted five sets of lamp posts and went with that (I could have also used the track at a local high school, but at this time of day the kids are still there).

To get an estimate of my pace over the various segments of the run, I manually hit the lap button at roughly 1km intervals and remembered where they landed. When I got back home, I then mapped it out using RunSaturday's (more on this later) mapper and manually entered the lap distances in ProTrainer (giving me split times, distances and average pace). Fortunately, I was relatively accurate and most of the laps ended up being pretty close to what was intended. I did, however, lose count at some point during the run as the total distance was exactly 1km longer than planned (12.25km vs. 11.25km).

In retrospect, the pace was a little higher than I planned on doing the run (overall average of 4:33/km vs. 4:45/km). That isn't unexpected, however, as doing 5K races tend to make me a little too enthusiastic and getting back into control generally takes a few runs even with the watch ;) Normally, when pacing information isn't available I'd use heart rate to guide me, but strides tend to throw that off a bit. I likely could have done this in the second half of the run, but I was feeling good and elected to just run naturally for a change ;) In the end everything worked out well, however, and functionally that's all that really matters.


This weather has also prompted me to start thinking about when to get my bike changed back over for outdoor use. When I moved to the indoor trainer, I had some old tires put back on so that I didn't ruin the good ones over the winter. Between the wear that the trainer has put on them, and the gashes that prompted me to replace the tires in the first place, I don't really trust them on the road right now. Conversely, if I switch back to the good tires I'd be hesitant to do any significant mileage on the trainer as I don't want to wear them out prematurely.

As such, I'm going to have to pick a point to switch from indoor to outdoor training. While the weather is nice right now, it's still early in the season so I'm not sure I want to tempt the fates at this point ;) I'm tentatively thinking about bringing it down with me prior to the Harry's 5K in April (my bike shop is near that course), and have them make the adjustments while I'm running the race. Hopefully I'll have figured out the cycling computer stuff by then as well, as it would be nice to get that installed at the same time. Ultimately though, I likely should get another set of wheels so that I can switch between the trainer and outdoor riding on my own.

Polar RS800sd Review

Introduction

A little over a year ago, I picked up a Polar RS800sd to help analyze my exercise regime more accurately and find ways to improve it. Since then, I've been using this tool extensively for my day-to-day workouts and have spent a lot of time getting to know everything about it. In that time, I started a serious running program and progressed to running a half marathon, so I also have a wide range of experience as both a beginner all the way up to an endurance athlete.

When I was first investigating the myriad of choices in running computers last year, I found it extremely difficult to find any detailed information about them. The manufacturers had basic specifications and user manuals to read through, but the reviews that existed either had very little detail or were simply a re-hashing of marketing information put out by the manufacturer. As such, I figured that it would make sense to share my experiences about this tool in a good deal of detail for anyone who might be investigating them at this point in time.


Features

• Speed and distance recording via S3 footpod, providing accurate readings of both overall and instantaneous measurements.
• W.I.N.D. heart rate monitor measures heart rate with single beat resolution.
  
• Barometric altimeter measures elevation changes more accurately than GPS-based systems.
• Measurement of running cadence and stride length.
• Configurable interval training features with alarms for maintaining speed, heart rate, etc.
• Lap markers can be added manually or automatically to provide context to raw data.
  
• Coded 2.4GHz radio communication is less susceptible to interference than the 5kHz system most Polar running computers use.
• Compact S3 footpod is significantly smaller and lighter than its predecessor.
• All exercise displays can be customized, with six individual screens that can be selected when in training mode.
  
• Monitors mileage of up to two pairs of shoes in the watch itself.
  
• IrDA computer interface for uploading training data and configuring watch.
• Polar ProTrainer 5 software provides tools for analyzing exercise data, and maintains a detailed training log.
• Can perform a number of simple tests to determine physiological parameters such as VO2Max.
  
• Heart rate monitor, footpod and watch all have user-replaceable batteries (albeit different batteries for each).
• Optional G3 GPS pod can be purchased for use instead of the S3 (RS800CX can use both simultaneously).
  

Components

There are three basic components to the RS800sd, the watch itself, the S3 footpod and the HRM strap. In addition to displaying the readings, the watch is also the component that collects and stores the data from the other sensors. The S3 footpod attaches to the shoe and is responsible for recording speed, distance, cadence and stride length. Finally, the HRM strap goes around the runner's chest and monitors the electrical activity in their heart, relaying basic heart rate data as well as R-R data (covered later in this article) to the wrist unit. I'll address each of these three components individually in the next few sections.


The S3 Footpod



Probably the most important component of the RS800sd, the S3 footpod can either be attached to the shoelaces (using a provided accessory) or placed inside of a special cavity in some Adidas running shoes. This small unit contains a set of accelerometers which are used to record the movement of the foot in three dimensions. A microcontroller in the S3 then translates that data into speed, distance, cadence and stride length values relayed to the wrist unit via a wireless signal.



Much smaller than its predecessor, the S3 measures a tiny 55x40x13mm and is barely noticeable when worn on the foot. A small battery compartment on the base of the sensor allows the user to replace the CR2430 battery (~$3.50CDN and lasts approx. three months). Other than that, there isn't a whole lot to say about it - it is turned on automatically by the wrist unit when necessary, so it has no buttons or controls of its own.

Footpod (Inertial) vs GPS

When looking at running computers, most products fall into one of two different categories - footpod-based systems like this, and GPS-based systems like those offered by Garmin. As mentioned above, inertial systems use a sensor attached to the shoelaces to monitor the movement of the foot and convert this into speed and distance information. GPS-based systems, on the other hand, capture and store a runner's location every second and calculate speed and distance using that information. Each of these systems has its advantages and disadvantages, and it is important to understand these characteristics when deciding which system to go with.

As footpods are a closed system, they aren't reliant on any external signals like GPS-based systems are. As such, users don't have to worry about buildings or tree canopies blocking reception of GPS signals (or waiting for the watch to acquire a fix in the first place). Further, as footpods are monitoring the movement of the foot rather than the movement of the runner, they can provide accurate readings when running on a treadmill. Finally, since footpods are measuring the gait cycle, advanced systems like the RS800sd can provide additional readings such as cadence and stride length that GPS-based systems have no way to monitor.

The downside is that as footpods are reliant on the movement of the foot they are only useful for tracking running performance. As GPS-based systems simply monitor the absolute movement of the athlete they can also be used to track performance in other sports (eg cycling). Further, as GPS-based systems log the exact route that was taken they also provide context that is not available when using inertial systems. While not critical, it can be helpful to have this information when looking back on previous workouts (eg a slowdown that might appear random on simple curves makes more sense when one sees that they were crossing a street at the time and had to deal with traffic).

Accuracy

The other major difference between Footpod and GPS-based systems is the nature of the error they introduce into the readings. Civilian GPS systems can only generally provide readings accurate to about 15 meters, which is quite a significant error when on foot. Fortunately, the components of this error that effect speed and distance measurements are random in nature so they tend to get averaged out over multiple samples. The result is that these systems can provide accurate readings over the long term (ie kilometer/mile splits, total distance run, etc.), but they aren't very good at providing instantaneous measurements (ie current pace, short intervals, etc.).

Footpods, on the other hand, can provide extremely accurate short and long term measurements but are dependent on accurate calibration. As these systems are reliant on monitoring the movement of the foot, variances in the gait cycle from person to person can introduce error into the readings. Unlike GPS, however, this error is static in nature - that is, it will repeatedly over/underestimate by a fixed percentage for any given gait. Thanks to this it is possible to eliminate much of this error by running a known distance (eg a few laps of a 400m track) and dialing in the difference as a calibration (ie if it reads 1616m after four laps, the watch will take 1% off each future reading).

The complexity with this is that it is dependent on the gait cycle of the runner, so any changes (due to running at significantly different speeds, aging/new shoes, injuries, etc.) can require re-calibration of the system. In my experience, however, once it was calibrated gait variances never added up to an error larger than 1% during the time that I've used it. I have, however, seen variances as large as 4-5% when replacing an old pair of shoes with a new pair without recalibrating (example). As such, it is still wise to calibrate it every once and a while to make sure that it is still giving you accurate readings. This is especially important for inexperienced runners whose technique may be in flux as they gain experience and strength.

In short, inertial systems have the advantage of significantly more accurate instantaneous measurements than GPS-based systems. When kept calibrated, both inertial and GPS-based systems will provide comparable accuracy over longer distances. When calibration isn't done, however, GPS will often provide higher accuracy for many people so they can be a lower maintenance option. Naturally, the decision of which system is better suited to a runner will depend on their priorities.

Cadence and Stride Length

As this is a relatively unique feature of this particular model, I feel that it is important to make a quick mention of this capability. When enabled, the RS8oosd can record and display these two biomechanical properties which can be quite valuable for many runners. Stride length is simply recorded as an average at the end of each lap, so its usefulness is limited. Cadence, however, is recorded every second and can be displayed in real time.

For a beginning runner this information can be quite useful, as slow turnover is a common problem for many people. Providing a real-time readout of this value allows the runner to carefully monitor their cadence, and makes doing drills to increase one's cadence much easier. When looking over the cadence plot after a run this can also be quite instructive as it gives the runner a better idea of how they dealt with it when they weren't actively paying attention.

For more advanced runners, cadence readings can also be a very useful tool. Over the course of a long run, the muscles in a runner's legs begin to get tired and their cadence will begin to involuntarily fall. This forces us to take longer strides to maintain speed which, in turn, increases the load on the muscles and accelerates the rate at which they get tired. By monitoring the cadence value and correcting for this as soon as it begins, endurance and overall performance can be improved. Further, looking over the cadence plots after the run will give the wearer a good idea of exactly when this began to happen and how it progressed, allowing them to make changes to prevent it from happening in any future runs.


Polar W.I.N.D. HRM Strap



The HRM strap is a relatively simple device which, as its name implies, measures the wearer's heart rate and relays that data to the wrist unit. This unit is basically a very simple EKG, which uses an integrated microcontroller to look for the QRS complex (each one triggering the heart to beat once), and sends a signal back to the wrist unit each time it sees it. The watch then averages out the rate at which these beats occur (on a per-second basis) and, if configured to do so, displays them for the user to monitor in real time. Naturally, this data is also stored in the memory of the watch for post-run analysis.

The strap consists of two basic components - a small sensor pod (shown above) and the strap itself (shown below). The former contains the transmitter, the monitoring electronics and a small user-replaceable CR2025 battery (still on my factory cell, but Polar estimates it lasts about two years). The later contains the sensor pads themselves and attaches to the pod via two metal snaps. Unlike many other heart rate monitoring straps, the sensor pads of this unit are made completely out of a soft textile material. As such, it conforms to the shape of the runner's body and will generally record more reliable data than units that use a hard plastic front with metal sensor pads. Further, the soft material is quite comfortable and one doesn't really feel it when running.



Additionally, as the electronic pod that measures the signal is an independent component, athletes can also buy some Adidas shirts that have the sensor pads built right into them. The sensor unit simply snaps onto the front of these shirts, allowing them to leave the strap at home. They can be a bit difficult to find in Canada, however I was able to find them in the US relatively easily. The little sensor pod in the middle of one's chest does look a little funny, however if it is simply used as a base layer with something else on top that isn't an issue.

As with other heart rate monitoring systems, the sensor pads do have to be wet in order to get a good signal. As such, users simply have to moisten them before they head out for their run. Once one gets going the pads will generally stay wet as the wearer begins to sweat. The only caveat with this is that prior to races they can dry out before one starts, but it is relatively easy to take it off and give it a little squirt of water before beginning. Worst case scenario, it only takes about two to three minutes of running to get dry pads moistened so it doesn't really cause a lot of problems.

R-R Data Recording

In addition to the standard averaged heart rate data that similar products provide, Polar's unit also transmits the time between individual beats of the heart. On the wrist unit, this data is used to provide an optional 'R-R Variability' readout that gives users a rough idea of how stable their heart beat is. At heart rates below the aerobic zone the heart rate varies significantly, but as the rate increases it becomes more periodic in nature. As such, this data is apparently used internally by the watch to determine when runners reach certain training zones, as well as to provide a score ('Running Index') for the quality of the overall run. I haven't found this terribly useful while in the field, as you really have to monitor it pretty closely to see how it is changing, but it is not a default reading so it's easy enough to leave switched off.

After the fact, however, the R-R data can be quite useful when analyzing a run. Primarily, it makes it much easier to see exactly when the monitor was having trouble getting a good signal from your heart. The watch/software seems to have a pretty good mechanism of working the noise out of the averaged heart rate curve, so it can look relatively clean even when the signal is weak. The R-R curve, however, makes it relatively plain to see when there was even the slightest problem, as the curve tends to be pretty noisy if the strap slips out of position. As such, it gives wearers a very good way to determine the reliability of the data shown. Further, this information is invaluable when first using the device as it allows users to get a good idea of how well they've positioned everything.

When the sensor is seated correctly, the R-R data gives users a much higher resolution look at the activity of their heart during a run. The curve records each and every beat of the wearer's heart during the session and plots it out in the included software. As such, if a user was running at 180bpm, they will have three readings for every one in the standard curve. This is naturally not necessary for everything, however it can be very useful for tasks such as analyzing exactly how well one recovers after a hard lap during an interval session.

Polar RS800 Wrist Unit



The centerpiece of the system is the wrist unit itself, as it is the component that users will be interacting with most directly. It is responsible for coordinating the other sensors, recording the data and displaying the real-time readings. In addition to these tasks, the watch also contains a barometric altimeter that records any changes in elevation. Naturally, the watch face and five buttons provide access to the multitude of options and settings offered by the watch.

The various sensors can be switched on and off via menus in the watch itself, and countless settings allow you to specify exactly how it handles the data that it receives. With all options enabled, it has enough memory to store about four hours of telemetry. By bumping the recording rate down to 5 second intervals (from 1 second), this capacity is increased to 11 hours. By disabling R-R and altitude recording, you can bring it to over 30 hours. In its most bare bones mode it can store almost 1900 hours of data, but that provides no speed/pace data and a recording rate of one minute so its utility is limited.

As it doesn't need a GPS radio or antenna, the RS800 watch is much smaller than many of the other products aimed at this market. With that said, it is still a pretty big unit when compared to normal watches. Regardless, it is small enough that it's comfortable to wear and it doesn't really get in the way when running. It is powered by a small CR2032 button cell battery, which is user replaceable via a small cover on the back of the watch. While it is not rechargeable, this battery lasts for about a year and costs less than $4CDN, so that isn't a big issue.

The watch is controlled by five buttons, a large red one on the bottom face of the watch and four small buttons around the edges. The top right button switches the backlight on, and when held down during exercise provides some basic options. The bottom right button pauses the exercise session, and a second press stops it. The buttons on the right side navigate up and down through menus, and during exercise they select which data to show (you can scroll through six different screens with three pieces of (user configurable) information on each). Finally, the red lap button initiates workouts, marks laps during exercise and acts as a general 'ok' button in many of the watch's internal menus.



On the rear face of the watch unit is a small opening for the barometric altimeter used by the RS800sd to measure elevation changes. This method is significantly more precise than GPS-based elevation measurements, and can accurately detect changes of a few inches. The downside, however, is that changes in atmospheric pressure (eg a storm system passing through) during a session will incorrectly manifest themselves as changes in elevation. Naturally, as these changes generally occur pretty slowly (relative to changes in elevation) they are relatively easy to correct for after the fact but one still has to keep them in mind. The other caveat is that the watch doesn't appear to record elevation on a per-second basis like the other values (subjectively looks like 3 sec intervals), so short rises/falls might not be recorded completely (ie a runner may crest the hill between two readings).

Finally, the top of the watch face has an IrDA transceiver that allows it to communicate with a computer using the included ProTrainer 5 software. This allows the user to upload the detailed telemetry from their run into the computer, where it is stored (and can be analyzed) in a detailed training log. Further, all of the settings provided in the watch can be configured from the software as well - making it easier to make detailed adjustments. It should be mentioned, however, that the RS800sd does not come with an IrDA adapter for the computer, so most people will have to buy this separately. Polar does sell an adapter for $70, however as the watch uses the standard IrDA protocol you can buy the necessary adapter (minus the Polar logo) for less than $10 at any electronics store.


Polar ProTrainer 5 Software



The main benefit to using a Running Computer like the RS800sd is the ability to analyze the details of one's exercise regime. This includes looking over the telemetry from an individual run as well as looking over aggregate training logs to see exactly how well one is progressing. The watch and sensors perform the function of providing immediate feedback and data recording, however the last piece of the puzzle is the software that takes all of this raw data and allows runners to examine it in a meaningful way. In the case of the RS800sd, this duty is performed by the ProTrainer 5 software package that is included in the box.

Walkthrough

When ProTrainer 5 is first launched, the user is presented with a calendar view (shown above) that provides a high-level view of the overall training program. All of the exercises that are uploaded from the watch will be displayed in the calendar, and the user can manually add any sessions where the RS800sd wasn't used (eg swimming). Double clicking on any day in the calendar will present another dialog that allows the user to drill down for more detail, however I'll get back to that a little later.


Each individual exercise entry includes a user defined name, followed by a line containing the sport (R=Running, C=Cycling, W=Walking, etc.), the amount of time taken to complete the session (if available) and the total distance covered. This is naturally very basic information, however it is sufficient to give a rough overview of what was done on any given day. I should note that older versions of the software (which was used to download the two days shown above) placed R-R data (beat to beat heart rate curves) as a discrete exercise (not counting towards totals), however a recent update now bundles that along with the main exercise.

At the right edge of the screen are a set of panels that summarize the overall activity for each training week (see above). This lists the number of exercises, the total time and distance that was recorded during the week and the number of Calories burned. Further, the graphic at the bottom of the panel charts the amount of time spent in each of the five training zones. These zones are user configurable, but by default they are set to 10% increments of the user's maximum heart rate (ie red=90-100%, yellow=80-90%, etc.). This provides a good deal of information about overall training volume and intensity for each week, and allows the athlete to see how well they've been doing at a glance.


As noted above, to get further information the user simply double clicks on a day in the calendar view which results in the above dialog. The first tab provides the ability to keep track of basic information about the day itself. The user can enter a short note, log the weather/temperature, as well as a few basic physiological parameters. If this isn't manually filled out, the data from the previous day will simply be moved forward so it doesn't need to be modified unless something changes.


The exercises performed on the selected day appear as tabs along the top of the dialog, and clicking on them will bring up the above dialog. The left panel contains basic stats about the workout, all of which can be modified by the user if desired (and are relatively self-explanatory). The top-right panel contains the exact time spent in each of the training zones (mentioned above) during the selected session, as well as the total time of the workout.

For exercises uploaded from the watch, the panel in the bottom right corner is generally the most important. A small thumbnail provides a simple view of the data, with a set of buttons underneath allowing the user to pull up more detailed information. Double clicking on the thumbnail brings up a detailed plot of the exercise session.


The detailed plot (shown above) allows the user to examine the telemetry from the session directly. When all of the options are enabled, the chart will contain plots for stride length (green line), heart rate (thin red line with white fill), elevation (thick red line with red fill) cadence (green line) and pace (blue line). The background is colour-coded with the heart rate zones that were configured for the selected sport.

Laps are marked along the bottom axis of the plot, and hovering a mouse over any of them will bring up a summary of critical stats (time, lap time, distance, average pace, heart rate at the end of the lap, average heart rate, average speed, average altitude, total ascent, grade, vertical ascent rate and cadence average). Manual laps (triggered by pressing the red button during exercise), automatic laps (generally used to mark km/mi splits) and phase markers (used for programmed interval workouts) are designated and numbered separately so they are easy to keep track of. Right clicking on the plot and selecting 'Lap Times/Markers' allows you to get more detail, as well as add/remove/modify laps as desired.

Just to the bottom left of the plot is a set of instantaneous data readings (time, heart rate, Calorie rate, pace, distance, cadence, altitude, ascent and descent) corresponding to the selected point in time. When first opened, this will reflect the starting point of the session but clicking anywhere on the plot itself will move the cursor to provide you with data from that point in time. Pressing the left and right arrows on the computer will move forward/back in one second intervals (or whatever sampling rate was selected) so the user can step through the session.

To the bottom right of the plot is a grade summary for the session, outlining how much of the session was spent on flat ground, ascending inclines and descending. Both time and distance figures are provided for all three, in both absolute and percentage terms. Naturally, the detailed elevation plot is generally more useful but this information can be handy for route comparison purposes.

Finally, the very bottom of the plot includes a summary of the overall workout. This section provides exercise duration, distance, heart rate (avg/max), pace (avg/max), cadence (avg/max), running index and ascent. The running index field specifies a synthetic score corresponding to the overall quality of the session. Polar isn't explicit about exactly how this is calculated, however it seems to correlate tightly to the ratio of speed and heart rate. I'm not entirely sure how accurate it is, however, as the score of 61 that I usually get is supposed to correspond to a 1:30 half marathon which is about twelve minutes faster than my recent race.

Customization

Polar ProTrainer also offers the option to customize many areas of the wrist units operation, as well as to create and upload custom exercises. When the user goes to the Tools->Edit Polar Product Settings menu, a tabbed dialog (shown below) is provided that offers a plethora of options.

The first tab (General) provides an overview of the wrist units current state. It includes a summary of the amount of available memory (as well as buttons to manage entries), a readout of the level of charge remaining in each of the three batteries (watch, HRM and footpod) as well as overall totals. The second tab allows basic watch functions to be configured (time and date, adding alarms, etc.) and is relatively simple so I won't cover it here.

The User tab allows athletes to enter basic information about themselves, that will be utilized by a number of algorithms within the wrist unit and the software to calculate values such as calories burned and the running index. All of these values can be updated on the wrist unit as well, however they are much easier to enter in bulk with a proper keyboard and mouse.

The Product tab controls a number of aspects about how data is recorded and displayed by the wrist unit. The Sports Zones button allows the user to customize the heart rate zones that are used for both the reports and for certain real-time displays that the wrist unit can present to the runner during a session. Finally, the 'Customize Exercise Displays' button launches another dialog that allows the user to control which data is displayed when the footpod is disabled (for some reason a different button on the 'Run' tab controls the displays used when it is available).

The 'Run' tab is likely one of the most significant panels available within this dialog, as it controls a lot of the central functionality offered by the running computer. It allows you to enable/disable the footpod, select whether the wrist unit should display pace (min/km) or speed (km/h), modify the calibration factor and a number of other variables. Most significantly, however, is the 'Customize Exercise Display' button, which allows the athlete to control how data is displayed on the watch during exercise.

Each of the six columns in this dialog represent one of the 'pages' of information that the wrist unit will be displayed. The watch face displays one page at a time, and the buttons on the right edge of the wrist unit allow the user to cycle through the pages as desired. Each of the pages can be disabled if desired, and what is displayed in each of the three available slots can be selected by the user. For reference, the available information is as follows:

• Altitude - A simple readout of the watches current altitude in feet or meters.
  
• Ascent* - The gross distance that the runner has ascended during the current session.
  
• Cadence* - A readout of the number of steps that the runner/walker is making per minute.
  
• Calories* - The total number of calories consumed during the current exercise session.
  
• Countdown Guide* - Displays remaining time or distance in the current exercise phase. When running in a phase without a target (or running a 'free' exercise session), it simply displays total time.
  
• Distance - The total distance covered during the current exercise session.
  
• Exercise Time - The total amount of time accumulated in the current session.
  
• Heart Rate - The current heart rate reading (in beats per minute) that is provided by the Wearlink strap.
  
• Lap Distance* - The total distance accumulated in the current lap.
  
• Lap Time - The total amount of time accumulated in the current lap.
  
• RR Variation* - The average variance (in milliseconds) between individual heart beats.
  
• Speed/Pace - A readout of the instantaneous pace (or speed) of the runner/walker.
  
• Target Zone* - A readout of the current training zone that the wearer is in.
  
• Time of Day* - A simple clock readout to provide the current time of day.
  
• Zone Pointer* - A graphical readout of where the current heart rate falls within the training zones.

* The entries above listed with an asterisk are only available in the top two rows of the display. The lower row offers a smaller number of selections as it uses a fixed element LCD rather than the bitmapped display used by the upper two.

This provides a good deal of flexibility so that the user can select exactly what information they want available and how to organize it. The above fields cover pretty much anything that runners will likely want access to, and the availability of six selectable screens allows that information to be retrieved without much difficulty. The default configuration works relatively well, however no layout is perfect for everyone so the ability to customize it to this level is quite helpful.

The next major tab allows the user to prepare preprogrammed exercise sessions which the wrist unit will guide them through. The RS800sd can store up to ten exercises at any given time, and if more are necessary the software allows users to save them to disk and call them back when necessary. When an open slot is available, the three buttons across the top of the dialog allow the user to create new sessions - either by a simple zoned exercise (with a single set of targets for the entire session) or a complex phased exercise (with a number of phases, each with their own individual targets).

When the user creates a phased exercise, the above dialog is used to build and prepare each of the phases. In this case, an 8 mile run with ten 100m strides is planned with heart rate targets programmed into each phase. The panel at the bottom of the dialog allows the phases to be prepared and re-ordered, with the following dialog provided to allow customization of each individually:

Using this dialog, the athlete can name the phase, specify how it is initiated (automatically when the previous phase ends or manually by pressing the red button), the duration of the phase (manual, time, distance or when a specific heart rate is reached) and what sort of targets the user would like to aim for (none, preprogrammed training zones, manually specified heart rate range or a pace range). Further, the bottom panel allows the user to specify that one or more phases is repeated a number of times which is helpful for interval training sessions.

Once the phases have been built up, the diagram near the top of the exercise dialog illustrates the overall workout as well as the specified targets. The top right of the dialog provides an estimate of how long the run will take, as well as how much distance will be covered. Once complete, the exercise can be given a name and short description, then uploaded to the watch.

The next time an exercise session is started, the user can then select this exercise and the wrist unit will walk them through the session. When the specified phase is complete, the watch will beep to signal the user to change to the next phase (the name of which is shown on screen momentarily). If targets have been set for the current phase, the wrist unit will also sound an alarm whenever the runner falls outside of the specified range (this can be turned off during the session if desired). After the run is complete, the watch will provide a summary of a number of critical details (time spent, distance covered, average pace, heart rate, cadence, etc.) broken down by phase. Naturally, phase changes are also marked on exercise plots when examining them in ProTrainer.

That covers the main functionality of the ProTrainer 5 software. The package does offer additional features like entering an exercise plan and generating detailed reports of your progress, however this article is already getting pretty long so I'll stick to the basics outlined above. Regardless, the functionality discussed above covers most of the core features that most people will use in a good deal of detail.

Variants
G3 GPS Sensor

In addition to the S3 footpod, the RS800 can also be used with a GPS device called the G3 that provides distance and speed data. This model is generally purchased as part of the RS800G3 bundle, however RS800sd users can also purchase the sensor separately and use it instead of the S3 footpod that came with their watch. Note, however, that the RS800, RS800sd and RS800G3 can only use one of these sensors at any given time so the user must select which mechanism they would like to use (although this is a simple menu item, so it can be done on a session-by-session basis). It is also important to note that these models do not store a tracklog of the route like other GPS-based products, instead simply storing the calculated distance and speed data.

RS800CX

Recently, Polar has released a new revision of this training computer offering a few additional features. The core design and operation of the new model is basically identical to the RS800sd, so most of the above is relevant to this model as well. The major differences are as follows:

• Compatibility with Polar W.I.N.D. speed and cadence sensors for bicycles allows the RS800CX to work for both running and cycling workouts.
• When used with the G3 GPS sensor, can now record a map of the route taken during the session.
  
• Ability to connect to both the S3 footpod and G3 GPS radio at the same time. This provides the route recording capability of GPS and combines it with the accuracy of the footpod mechanism.
• Automatically falls back to alternative tracking if the connection to the primary sensor is lost (eg if the footpod battery dies, GPS will take over).
• Ability to monitor up to four pairs of shoes (vs. two in the RS800sd).
  
• Allows the ability to append new session onto an existing session when the later is started shortly after finishing the former.
• A number of other small refinements to the overall design of the system.

As such, the primary advantages of the RS800CX over the RS800sd is for multi-sport athletes who need the addition of the cycling functionality. As I'm currently both a runner and cyclist, the RS800CX would have been a better match had it been an option when I was buying it. For someone who simply runs, there isn't really a lot of material difference between the models (although if buying new you might as well buy the CX).

One thing that should be mentioned is that some Polar distributors appear to be offering the option of upgrading the RS800sd to the RS800CX. There is unfortunately no company-wide policy on this front, however in countries where the service is being offered existing customers can send in their RS800sd and pay to have the electronics replaced to make it the functional equivalent of the new RS800CX. I haven't really looked into what the situation is in Canada as of yet, however I likely will give them a call at some point to examine the possibility.

Technical Details:

As the RS800sd uses wireless transmitters in each of its components, Polar is required to file documents with regulatory bodies in countries where it is sold. In many countries, these filings become part of the public record and thus can be pulled up by those interested - providing internal photos and details of the devices that aren't available from other sources. The American Federal Communications Commission does just this, and fortunately their filings can be pulled up via a simple web search. As such, for those technically inclined readers interested in such detail the appropriate filings for the components are as follows:

RS800 Wrist Unit: INWK1
WINDLink HRM: INWK2
S3 Footpod: INWJ9
G3 GPS Pod: INWM5

Interestingly, when pulling up the above URLs I also found this entry (INWR7) detailing a bluetooth-based HRM module similar to the WINDLink (named Windlink+ in the filings). Currently Polar uses a proprietary 2.4GHz protocol for communication between their sensors, but moving to an open standard like this would make it easier for third-party products to add compatibility for these products (much like the open ANT+ protocol used by Garmin).

Weaknesses

While the RS800sd is an extremely powerful tool, like anything in the market it does have a few rough edges. These aren't really huge issues, and many of them likely fall into the nitpick category, but for completeness sake a quick summary is as follows:

• The RS800sd uses an integral wrist strap instead of a standard strap coupling, which means that when it wears out you have to send it back to Polar for repair. Further, the lack of a user-replaceable strap means that one has no option to go with an alternative design.
  
• The beep signal sounded by the wrist unit when an auto-lap occurs is the same as the phase change signal, potentially making it difficult to differentiate them. When an automatic lap is triggered during a phased exercise, it is easy to get confused and interpret it as signalling the end of a phase. Ideally, it would be nice to have a number of different signals that could be selected for different types of phases.
• Given the rapid decline in flash memory prices, it would be a significant benefit to have more than four hours of capacity with all features active. While this is generally enough for any individual running session, more memory would mean that it wouldn't have to be synchronized with the computer as often (especially significant when travelling). It was understandable when the RS800sd was released years ago, but it would have been a nice step to add more memory to the updated RS800CX that was released late last year.

Things that Could be Improved

Aside from the direct issues listed above, there are a few refinements that would make the RS800 a better product. These items aren't really faults with the design itself, but instead little things that could be done a little better:

• When configuring phased exercises, it would be beneficial to be able to specify a total distance value in the duration field of each phase. On many occasions it would be beneficial to have variable length phases (eg the recovery portions of an interval workout) but still maintain a fixed distance for the entire run. At this point, users can only specify a distance or length of time for each phase in isolation so getting a fixed total distance means that all phases need to be distance-based.
• Switching the IrDA connection to a radio frequency based option (possibly Bluetooth-based given the above filing) would make for a more elegant solution. While IrDA ports may have been common when the RS800sd was released, it has largely been supplanted by RF technologies. Aside from more people having the requisite hardware already, using RF would remove the annoyance of having to maintain a line-of-sight connection when uploading.
  
• As noted above, changes in barometric pressure can manifest themselves incorrectly as changes of altitude. Incorporating a second barometer and a simple data logger into the infrared interface (which stays at your desk) would allow the software to completely eliminate this error. Given the extremely high precision of the built-in altimeter, this would yield a nearly perfect elevation record.
• Adding a mechanism to allow calibration factor to be changed on-the-fly when it is apparent that it is off. Currently, the calibration procedure requires you to initiate it before running the known distance. In some cases, however, it's easy to change shoes and forget to update the calibration. When this happens, it would be nice to simply select a menu item at a known point and change the calibration on the spot.
• Furthering the above, when using both the S3 and G3 it would be nice to offer an automatic calibration option that will detect any error. While manually calibrating the footpod would be more accurate, a system like this would provide most of the benefits of an inertial system without the user having to worry about maintaining calibration.
  
• Adding electronics in the footpod to detect the activation signal from ChampionChip timing pads and drop a lap marker would be extremely helpful when racing. Every finishing photo that I have shows me looking down at my wrist to press the stop button, and adding a simple feature like this would allow me to let the device do all the work. While it would add some cost to the product, the system would only have to detect the signal rather than interpret it.
• If at all possible, it would be nice to use the same type of battery in all three of the sensors that work within this system. Right now, each of the sensors uses a slightly different button cell battery so it's a bit of a pain to pick up replacements. This isn't really a very big thing, but it's just a matter of a more elegant configuration.
  

Conclusion

The Polar RS800sd is an extremely powerful tool, and with the associated software it can provide Runners with a lot of critical information to improve their workout regime. It records more data than any other running computer on the market, and does so using some of the most advanced technology available. The footpod-based system does require a certain degree of attention on the part of the user to keep it accurate, but for those willing to expend the effort it yields the most accurate results currently available.

Heart Rate Training

I was asked by one of the instructors at my local Running Room shop to give a talk on heart rate training, and I delivered it on Tuesday. I began using a heart rate monitor about 16 months ago when I was still in my power walking regime, so I've made heavy use of this technology for the duration of my running career. Being a technically minded individual, I've dug up all of the information that I can on this topic and figured that this would be a good opportunity to share what I've learned. As I did the work to compile this information, I figured that I'd upload a copy of my notes and the handout to this blog in case someone else might find the information handy.

Running is naturally an aerobic sport, and performance is primarily governed by your body’s ability to move oxygen from the air and get it to your muscles. Heart rate monitors are tools designed to allow you to objectively monitor the performance of the systems responsible for this task. This, in turn, allows you to make sure you are getting the most out of your training.

There are three basic variables that control the quantity of oxygen that your cardiovascular system can transport. Firstly, the composition of your blood determines how much oxygen it can carry in a given volume. Secondly, your stroke volume determines the amount of blood that your heart moves in each beat. Finally, your heart rate determines the number of beats per minute.

The first two parameters are basically fixed in nature. With sustained training, they will improve, but that process occurs over the period of weeks and months. As such, your heart rate is the only mechanism that your body has to adapt to short-term demands. By monitoring this value, like watching the tachometer in your car, you can objectively determine your training intensity at any given time.

Unlike a car, however, the human body can adjust itself to deal with changing demands. When your systems are repeatedly put under stress, they will make adaptations to better deal with those stressors in the future. Training programs, such as the one that you are following now, stress your body in a controlled manner in order to trigger a specific set of adaptations suited to the target race.

The catch, however, is that the adaptations that the body makes are very specific to the stresses that are applied. Each of the different types of runs in your schedule has different objectives, so it is critical that they are done at the correct intensity. If they are done too hard or too easily, they will trigger different adaptations than intended and leave you improperly prepared when it comes to race day.

The tricky part of this is that it is often difficult to figure out exactly what the correct intensity is. Trying to tie it down to a specific pace is problematic as the mapping between intensity and pace is dependent on a number of variables. Further complicating this, as your fitness improves you will be able to run at faster paces at a given intensity.

Naturally, this is exactly the reason why heart rate monitors were created. By targeting specific heart rates during your runs, you will be able to precisely target the correct intensity and trigger the intended adaptations. As you get stronger, your heart rate for a given pace will become lower, allowing you to see when you need to step things up a bit to keep the stressor in place.

To simplify this process, physiologists have developed a structure composed of five different heart rate zones. Each zone encompasses a range of heart rates, and carries with it specific training characteristics. Nearly all modern HRMs provide tools to determine which zone you are in, as well as to analyze how much time is spent in each. Naturally, depending on what you are trying to achieve, the importance of each zone to your training program will vary.

The lowest zone on this scale, zone 1, is for extremely low intensity work such as a light walk or slow jog. Naturally, it produces little stress on your body, and therefore produces little to no training benefit in and of itself. With that said, it does serve to get the blood flowing and helps to warm up your tissues prior to heavier work. Similarly, at the end of the workout it is also potentially useful for clearing excess lactate from muscle tissues. As such, this zone is primarily used for the warmup and cooldown segments of your workouts.

The next step up the ladder is zone 2, which generally represents the bottom edge of what is considered aerobic exercise. For most people, running in this zone will require a conscious effort to slow yourself down and is basically akin to the long-slow distance runs that you do on Sundays. Due to this, it is often the most under-appreciated zone despite its critical role in improving a runner’s efficiency.

The energy that your body needs is provided from two primary sources – carbohydrates and fats. The former is naturally the ideal fuel; however your body can only store a maximum of about 2500 Calories in this form at any given time. The later, on the other hand, provides energy at a much slower rate; however each pound of fat can provide about 3500 Calories. If you are carrying 30 lbs of fat, for instance, that translates into a store of 105,000 Calories at your disposal. As such, when it comes to long distance running your ability to make use of that energy becomes critical to your success.

Whenever you run, your body burns a mixture of these two fuels. The higher your heart rate, the larger the percentage of carbohydrates you will consume. In zone 2, the majority of your energy is drawn from your fat stores. Because of this, spending time in this zone stresses the metabolic pathways responsible for burning fat. Over time, this will improve the efficiency of these systems and, in turn, allow a larger percentage of your energy to be drawn from your fat stores even at higher intensities.

For endurance sports, this is a critical adaptation as significant depletion of your carbohydrate stores becomes more and more likely as the length of your runs get longer. While complete depletion is unlikely in the half-marathon distance, it takes some time to regenerate those supplies between training sessions so it can negatively affect your ability to train properly. Every Calorie of energy that comes from fat is a Calorie that remains in your carbohydrate reserves, allowing you to recover for the next session faster.

Moving up another level, zone 3 is generally the range where people will naturally run without any conscious effort to control pace. This relates to the steady runs in your training schedule and will generally provide the bulk of the mileage that you rack up on a weekly basis. Running in this zone begins to stress the cardiovascular system, and triggers the body to make a number of changes to improve the transport of oxygen to the muscles. Primarily, it increases the density of capillaries in the muscles responsible for running, making it easier to get oxygenated blood to your muscle fibers. Secondly, it builds the strength of your heart muscles; thereby increasing the amount of blood it can pump with each beat (the stroke volume, mentioned above). This, in turn, means that your heart rate can run at lower levels for a given output level – allowing you to run faster in each of the zones covered here. As such, these adaptations are critical to pretty much every type of running and form an important part of any training plan.

Next up is zone 4, which is likely one of the most important zones for the half marathon distance. Running in this zone will typically require you to push yourself to maintain the pace; however it is slow enough that you can sustain it for significant distances. As such, this is the level that you will typically run races longer than 10K (including the half marathon). With that said runs in this zone take a lot out of you and will require significant recovery time, so there are limits to how much mileage you can accumulate in it.

This zone represents the level at which you begin to reach the limits of your ability to supply sufficient oxygen to your muscles. When this happens, your body must rely on its anaerobic pathways. This produces a byproduct called lactate that will accumulate as long as the oxygen deficit persists. When it builds up to a sufficient concentration, it causes pain and will begin to negatively affect the ability of your muscles to produce power.

Fortunately, your body is capable of clearing this substance from your blood in parallel with its production allowing you to push a little harder than you would otherwise be capable of. As such, there is a point within this zone called the lactate threshold where the rate at which lactate is produced exceeds the capacity of your body to clear it out of your system. When you run at or below this level, you will be able to sustain it for an extended period. If, however, you exceed this threshold, lactate will build up and eventually force you to slow down. The further you go beyond the threshold, the faster that this will become an issue.

As with the other zones, training at this threshold triggers a number of adaptations that will help to improve your ability to run at race pace. Primarily, it stresses the metabolic pathways responsible for processing lactate in your bloodstream. This, in turn, results in improvements in these systems that allow you to clear it faster and more efficiently – pushing the threshold to higher intensity levels. Secondly, repeated exposure to significant concentrations of lactate will trigger your tissues to develop a tolerance to it. This, in turn, will increase the concentrations necessary to cause problems and allow you to run beyond the threshold for a longer period of time.

Your lactate threshold is the primary physiological characteristic that will determine how fast you will be able to run long distance races like the half marathon. As such, training sessions focused on working in this zone, such as your tempo runs, are critical to getting the most out of your goal race. While they don’t represent a huge portion of your weekly mileage, it is important that you focus on running them at the correct intensity.

Finally, we come to zone 5, which represents maximal effort exercise such as speedwork and hill training. At these intensities, you will accumulate blood lactate very quickly so you cannot sustain it for very long. Exercise in this zone will increase the maximum volume of oxygen (VO2Max) that your body can transport, and it helps to trigger a number of adaptations that increase your maximum speed. Working out in this zone is critical for short distance races like the 5K and 10K (as this is the zone you will race them in), however its utility is somewhat limited for endurance distances like the marathon and half marathon so I won’t go into any further details.




With the basics covered, I’ll move along to the equipment itself. Heart rate monitors operate by using a simplified electrocardiogram device that wraps around your chest. Two small sensor pads capture the electrical activity within your heart, and a small microprocessor then processes that data. The resulting information is then relayed to a wrist unit, which provides a real-time readout of this value, allowing you to use this value as feedback to adjust your training.

With all but the most basic units, this data is also recorded in on-board memory and can often be uploaded into a computer for post-run analysis. Further, higher-end models also possess the ability to monitor other parameters such as pace, distance and elevation providing the heart rate plots with critical context. These capabilities are nearly as important as the real-time displays, as it allows you to look back at your runs and evaluate what you did right and what you did wrong. In addition, it allows you to precisely monitor your progress over the long term and determine the effectiveness of your training regime.