Quantifying training

Repairing muscle microtrauma may not be the same healing a scraped elbow, but it's also not the same as restoring creatine kinase activity. I was trying to use a visual example that everyone has experienced to make the point that as the amount of damage increases the amount of recovery time needed increases. In my field, the rule of thumb is often 5 time constants for a process to be considered "complete." I don't understand what this means. Could you explain it or point me to an explanation? I don't even understand it enough to google an explanation.

I know people who were severely overtrained who needed months to recover (unfortunately they often didn't rest completely during the recovery...after all, these are people with a tendency to overtrain...) Overtraining is a medical condition that is very close to depression of nervous system. Time it takes to recover is no longer dependant on day-to-day / business as usual physiological changes, but rather on the time it takes to restore this fragile chemical balance (brain) responsible for letting the nervous system do its job correctly. That said, sever overreaching effects can take up to 21 days to fade away, which probably explains why certain 21day long tapering protocols have shown some results in certain context. In fact, we often talk and focus solely on tapers. In my opinion, the 3 weeks that preceded the taper are just as important since they set the magnitude of this overreaching. What you did 3-6 weeks before tapering should in big part, condition how long this taper should be. Intense race pace / vo2max training during this critical phase is gaining more and more popularity nowadays (even about long duration endurance athletes), since it's believed to create massive cardiovascular surcompensation (cardiac output, enzymes etc...). That calls for at least 14 day long tapers though.

The "time constant" is 1/|k|; it is related to the "half-life" by a factor of ln(2). Thanks Chris. So the "5 time constants" is the length of time to return to steady state. Pretty obvious reading your comment. I was trying to figure out how you would come up with 5 constants that were related to time which didn't even seem logical. It never helps to start off going in the wrong direction.

Wow, here's one very sound text on the subject of our little debate. And that one is definitely more inline with your experiment. I was thinking. May be a catch 22 debate here. Cause the time required to recover may be way too dependent on the intensity of the weight session (this can vary so much from one person to another), the age the gender etc. Anyway, read this, very nicely written. The only major omission is that the author doesn't really make any distinction between trained and untrained subjects. www.johnberardi.com/.../weightlifting.htm

I assume the impulse response model is using an exponential response of the form y = y_0*exp(k*t) To the best of my knowledge, sjstuart might want to correct me if I'm wrong here, fitness (work capacity) uses the following exponential constant Exp(-1/45) and fatigue Exp(-1/15) Given an accumulated base of 1000 as of yesterday, if I add a score of 100 for today, it would be computed as follow: Fitness effect = 1000 * Exp(-1/45) = 978 + 100 * 1 = 1078 Fatigue effect = 1000 * Exp(-1/15) = 936 + 100 * 2 = 1136 The net effect therefore = -58. If the ahtlete rests the next day then Fitness (or accumulated Base) goes down to 1054 and fatigue goes down to 1063 sjstuart may want to correct any misleading information here though.

In my field, the rule of thumb is often 5 time constants for a process to be considered "complete." So we're talking 5-10 weeks for full recovery from acute fatigue. The problem is that your fitness fades with a different decay constant (28-45 days). So (according to the model) you are still getting incrementally less fatigued after 3, 4, 5 weeks. But you're also getting less fit. Only for the first 2-3 weeks is the recovery from fatigue more than enough to make up for the loss of fitness.

This is WAY too much thinking for me. My formula is train hard during the season, taper 3-4 days at most for minor meets, taper 8-10 days for the major meets.

"Some experts have suggested that the taper effect may be due to surcompensating effects of other physiological mechanisms that are similar to those of glycogen loading. Although this explanation is vague, it may nevertheless be the best one currently available" (E.Maglischo, 2003). Without any more context, I'd interpret this as saying that recovery during taper may be analogous to restocking glycogen during carb loading. Not that the timescales are similar. I.e., overtraining followed by rest allows recovery to higher than previous levels of fitness (which sounds to me like the standard training effect), just like starvation followed by carb loading allows a temporary over-filling of glycogen levels. But the time scale of the former is ~2 weeks, and the latter is ~2 days. I don't assume from this that "muscle tissue damage recovery time goes parallel to time to replenish glycogen levels" (emphasis mine). Just like fatigue related mechanisms go parallel to blood lactate concentration. Wow, that's a whole different argument. I don't know about you, but I definitely feel fatigue long after my blood lactate concentrations return to normal. There are far too many, several too many many physiological changes that are taking place during the tapering process to explain performance enhancement solely on 1 of them. I agree wholeheartedly. Persisting in *micro-injuring* ourselves during the taper provides the best explanation for prolonged duration. Which implies that your 4-day "sudden break" would be more effective than a 2-week gradual taper. I agree that would not be a good taper strategy. But I think so because I don't believe fatigue has faded in 4 days. I'm curious why you don't like a full-stop taper strategy?

Yes, I understood that In that case, then, you're correct. According to the models, you're still "recovering" from the workouts you did 5-10 weeks ago. But 5 time constants out, you're 99.4% recovered, so you probably don't still feel tired. :) The model doesn't distinguish between regular training and overtraining. Recovery from both is assumed to be the same. Maybe it's just when you're overtrained that the damage is significant enough that you can still feel it many weeks out. Avoiding overtraining is actually where I get the most real-world use out of these models. But that's a separate topic that I think I'd better save for later.

Thanks for the links. I think the thing we're disagreeing on is the meaning of "fatigue". The 7- and 15-day constants in the models weren't made up. They were fitted to real results from real athletes. (Mostly trained, but perhaps not always.) If there were no measurable effect on performance at 3 days out, then the time constant would be much shorter. You say that "in exercise physiology, fatigue simply refers to the phenomenon that forces you to slow down as Lactate Level increase." But in the context of these models, the quantity defined as the "fatigue score" (or ATL in Coggan's model) is something very different. It's the residual effect of training (biological source unspecified) that has a negative effect on performance. I agree that my lactate concentration, glycogen, soreness are all recovered within a few hours or days of a tough workout (fatigue in your sense). But that workout will prevent me from swimming peak times for a somewhat longer time (fatigue in the model sense).