analyzing heart rate data

I have been using a heart rate monitor for a few years now. In the past I didn’t use it much more than for recording maximum and average HR during exercise.

This year I have started to realize the HRM’s true potential. Polar software can be used to analyze HR, speed, cadence, altitude etc. By comparing these parameters, it is possible to analyze your training rides and races.

The above is the data from my last 2 races (you can open the graphs copied into word by clicking on them):

• Tour of Yatsugatake
• Tour of Kusatsu

Yatsugatake Analysis

At Yatsugatake, the climb is relatively long (25km) and not too steep, with some flatter sections in the middle and steeper sections towards the end（red line）. Changes in speed tend to follow an easing of the gradient (blue line). The highest speeds are seen near the start (riding in the group), around the middle (through the flat sections) and near the end (short downhill before the road rises up to the finish). By changing gearing I could keep a relatively steady cadence at around 80rpm (green line). This year I feel that I am riding at a lower cadence with slightly heavier gearing than last year. Maybe this is a positive effect of winter strength training.

The heart rate line is the most interesting (dark red line). Similar to the data for speed, HR goes high early in the race when I tried to keep with the leaders and dips can be observed corresponding to flatter and downhill sections.

I have determined my heart rate zones, which can be seen in the background. The uppermost pinkish zone is the 5C anaerobic zone and involves rapid lactate build up. Exercise in this zone is not possible for a long period of time. The narrow red and green zones below this are zones 5B (aerobic capacity) and 5A (superthreshold). In these zones, which are above the lactate threshold, there is a slower rate of lactate build up. In theory, you can work in this zone for about an hour. In a race like Yatsugatake (just over an hour long) 5B and C form what is effectively the “race zone”.

At Yatsugatake, I went too hard too early. By trying to keep up with the lead group I forced myself into the red zone. After this point I found it hard to find a good rhythm and suffered with cramps. This no doubt slowed me down for a while as I tried to recover. As we got into the flatter sections about half way up, I felt recovered and rode at my own pace in the “race zone”. It’s hard to say but I think I could have rode better by keeping in the race zone. I went past Yoneyama san of Ravanello while going hard early on, only for him to come past me later on when I was suffering. Maybe he was paying more attention to his HR! I’ll ask him at the weekend!

Kusatsu Analysis

Kusatsu is shorter (12km) and less steep. I made an effort to stay in the race zone this time. This can be difficult as you are dictated by the pace of the riders around you, but you can help to keep you HR down by finding a good position in the pack, riding at a good cadence and trying to relax. As the race broke up, I was isolated and so had to go hard to try to keep a gap from two following riders. There are a couple of times when I went into the red but I managed to stay mostly in the “race zone”. Once I was caught by the two riders towards the finish, I took the chance to draft and recover. This can be seen in the lowering of the HR into the light green/yellow aerobic zones. Interestingly, speed also drops at this point. Later I made the mistake of sprinting too early. This can be seen in the spike in the blue speed line and followed by the HR line. Ideally this spike should correspond with the finish line. Unfortunately my timing was wrong! That one big dive into the red meant that it was impossible for me to keep with the other two guys and fight it out for 3rd. I’ll know better next time!

Again cadence was steady around the 80 rpm mark (green line). My one concern from this race is the general decrease in speed as the race progresses (blue line). Maybe the gradient increases further up the hill but I want to keep my speed for longer periods. After this weekend’s race at Gunma, I want to try to get some longer climbs (1 hour or so) into my training. I’ll do my best!

Thanks Adam showing me through the software. I know Analogue Andy still has lots to learn!!!!