Using TrImp to calculate CTL, ATL and TSB

I read with interest this article on Training4Cyclists.com. In it Dirk Friel talks about how to take the data from a powermeter and analyze it for training. Dirk explains about CTL, ATL and TSB.

Chronic Training Load (CTL) and Acute Training Load (ATL) are the technical terms for fitness and fatigue. The last remaining piece to track is form which is also known as Training Stress Balance (TSB). To calculate the three metrics (CTL, ATL, TSB) the rider needs to first track daily Training Stress Score values. We then take the 42-day rolling average of daily TSS to calculate CTL, 7-day rolling average of daily TSS for ATL and the difference between CTL and ATL is the Training Stress Balance. Training Stress Balance is what the athlete wants to see rise as their highest priority event approaches. Ideally CTL, or fitness, is near the highest of the season and ATL, fatigue, is low in order to have the form rise.

So my thought is that, even though I don't have a powermeter, maybe I can use TrImp scores to calculate the training loads and balance. I'm sure they won't give the same values, but maybe they correspond similarly to give the same type of feedback.

But being that I don't use a powermeter or the Training Peaks WKO+ software to figure all the numbers for me, so I have to figure the formulas out, and attempt to plop them into a spreadsheet to be able to try to graph it out. If anyone knows the formulas and can explain to me what they are and how I can apply them to use TrImp values insted of power, I would really appreciate it.

I guess I could use the powerscore from the GPS2Powertrack plugin in SportTracks and plop it into the formula. Again I have to stress that I don't know how accurate the powerscore is compared to an actual powermeter, so if I average a 220 for 2 hr powerscore ... I really don't know where it compares with those who really use an SRM or PowerTap to get data. But at least I would have a baseline for myself to guage progress through the season.

Another article I read was the VeloNews article titled 'Power at lactate threshold wins races'. This article explains that about producing more power at LT. You can find out your LT through testing, or you can guess. If you want to test it, do a 30 minute timetrial and find your average heart rate for the final 20 minutes. That's a good measure of LT heart rate. If you just want to guess, just use 85% of your max heart rate reserve.

The trick is to train your body to produce more power at LT without going above and taxing your system. I guess I can't explain it as well as Rick does in the article.

Think of it this way. In an event an hour or more long, how long can an athlete accumulate lactate before he/she blows? In the aerobic state, an athlete can pretty much go until the fuel is gone. Doesn’t it make sense to develop power in the aerobic zone where the majority of the race will be spent? Think of making the opposition go into a state of excruciating lactate induced burn while you cruise along semi-comfortably at threshold. That is the essential element of training the physiology of an endurance athlete.

Really this keeps with my thought of training either at high intensity or at recovery. I use heart rate zones to guage intensity. Zone 1 (<60%) and 2 (60-70%) are recovery. Zone 3 (70-80%) is the aerobic zone. Zone 4 (80-90%) is the high aerobic/LT zone. And Zone 5 (>90%) is anaerobic threshold. So in trainingyou are either training at zone 4 or higher, or you are recovering at zone 2 or less. Baisicly skip zone 3 for training.

This isn't to say you will not go into zone 3. You pass zone 3 going from 2 to 4. And there will be times where you will dip into zone 3 while attempting to stay in zone 4. You will inadverntly get enough zone 3 training, without trying.

So read the articles. I think I've made this post much longer that I wanted. Blah-blah-blah. It's late. It's flippin snowing outside. I don't think I'll make my week goal again this week. And I don't think I'll be able to ride much tomorrow.

Click here for Part 2.
Click here for Part 3.

training training power power watts watts TrImp TrImp Training+impulse Training+impulse cycling cycling bike bike cyclist cyclist Gunnar Gunnar Soroos Soroos ATL ATL CTL CTL LTHR LTHR TSB TSB