Originally Posted by An old Guy .
1)
http://home.trainingpeaks.com/articles/cycling/normalized-power,-intensity-factor,-training-stress-score.aspx
"TSS ... might be best viewed as a predictor of the amount of glycogen utilized in each workout. Thus, a very high TSS resulting from a single race or training session can be used an indicator that one or more days should be scheduled."
Please tell me what is a better view. (I can find nothing on the internet that indicates any scientific basis for TSS. Only that you came up with it
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2)
Given the quote above:
http://forums.roadbikereview.com/racing-training-nutrition-triathlons/tss-score-guidelines-114728.html
"what I [Andrew Coggan] and others have observed is that a long-term average (e.g., CTL) of ~100 TSS/d (i.e., ~700 TSS/wk) represents the point at which most people begin to feel that they 'adaptive energy' limited, versus simply being time-limited. OTOH, a long-term average of ~150 TSS/d (i.e., ~1000 TSS/wk) seems to represent an upper limit that few, if any, have been able to exceed for an extended period of time and not break down in some manner or another."
CTL and ATL are clearly related to TSS which you said is "best viewed as a predictor of the amount of glycogen utilized in each workout." It does seem that CTL and ATL are related to glycogen utilization. But glucogen replacement has a half life of 7 hours.
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4)
I am sorry. We both agree that "performance" is not related to TSS. So any claim that you can recover to perform again the next day seems out of bounds.
Had I anticipated your comments about Obrree I would have made the rides 100% for 1 hour vs. 55% for 3.3 hours both 100 TSS. Most of the guys here cannot do the first on multiple days, but most could do the second on multiple days. But as I said performance seems to be out of bounds.
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Give me some type of experiment that will show that those 2 rides should have the same TSS.
Our discussions could be more productive if you would state a bit more precisely what TSS measures. Right now I only have your comments on glycogen depletion/utilization.
1. See my previous posts: TSS is a global indicator of the physiological strain resulting from a particular "dose" of training, as determined by the combination of intensity (relative to FTP) and duration. As such, it
is predictive of glycogen utilization, (thus disproving your statement that it predicts nothing) - however, that wasn't my intent when developing TSS, and if I were to design a study to attempt to validate TSS, glycogen utilization would not be my first choice as a "gold standard" metric (although it is a handy way of illustrating the concept).
2. In the Performance Manager approach, CTL and ATL are indeed calculated from TSS, but the structure of the model (i.e., CTL/ATL/TSB and the associated math) is separate from the input function (i.e., TSS). IOW, you could use the Performance Manager approach with other metrics (e.g., Banister's TRIMP score) as well,
Based on the above, it should be obvious that the time constants of 42 and 7 d for CTL and ATL, respectively, have absolutely nothing to do with glycogen metabolism. Indeed, this is one of the conceptual limitations of the impulse-response model (upon which the Performance Manager is based and from which the time constants are derived), i.e., the model structure is almost entirely empirical in nature, and is
not based upon any underlying physiology.
4a) You misunderstand: properly interpreted, TSS
is a predictor of performance...however, that is because performance is related to stress (strain) and to adaptation, not because TSS is
directly a TPS (training performance score)
or TAP (training adaptation score).
4b) Doing all-out 1 h TTs on back-to-back days is a lot easier than you imply, and certainly easier than the impossible workouts you've suggested - indeed, on multiple occasions I (and others) have done back-to-back (and even back-to-back-to-back) 40 km TTs with <1 h (not 1 d) between them.
4c) Since TSS, the Performance Manager, etc., can't be said to have been scientifically-tested (only scientifically-inspired), the best evidence to address your questions/concerns comes from empirical observations, in particular what happens to CTL when people markedly change the composition of their training (e.g., shift from almost all level 2/3/4 to entirely level 5/6/7). What typically happens in that situation is that people have to reduce their training load somewhat, perhaps by 10-20%. Based on that, it would appear that TSS overestimates the stress of lower intensity, longer duration exercise compared to that resulting from shorter duration, higher intensity exercise. Rather than being disappointed in this result, though, I would argue that you should be impressed by it - after all, the notion that you can just "pin a number on it" and have a single metric adequately reflect all possible forms/types of training and their consequences is, on its face, simply ludicrous (as I pointed out when I introduced the idea). As it turns out, however, it is possible to do, and w/ sufficient precision/accuracy that the resulting tools are quite useful to know how to use them (just ask the recent Pan-Am TT champion's coach!). Perhaps more the point here, no one - yourself, most notably, included - have ever even
proposed any alternative, much less demonstrated that it is better/easier.
