djconnel said:Nice! Page 14, in particular, shows a cyclist getting sick in two cases of approximately 6 weeks at TSB ~ -20 in each case.
This suggests I could define an additional variable which describes the sustained TSB:
CTL(t) = (1/Tctl) integral of t' from 0 to t { exp((t' - t) / Tctl) TSS(t'😉 dt' }
Tctl ~ 42 days
ATL = (1/Tatl) integral of t' from 0 to t { exp((t' - t) / Tatl) TSS(t'😉 dt' }
Tatl ~ 7 days
TSB = CTL - ATL
Now I define quantity X:
X = (1/Tx) integral of t' from 0 to t { exp((t' - t) / Tx) TSB(t'😉 dt' }
or, equivalently:
X(t + dt) = (1 - dt/Tx) X(t) + (CTL(t) - ATL(t) - X(t)) dt / Tx
for some Tx (21 days? How long does it take to get in trouble?)
For the sample case, I'd guess he got sick
She, actually (it's my wife's data).
djconnel said:when X <= -20. But of course, there's a lot of other factors in getting sick...
Interpretation: TSB describes your rate of change of CTL. Averaging this over time should then describe how much training load has changed over the averaging interval. So "X" is describing how much CTL has changed over the past certain-number-of-weeks. But this is basically what you said 🙂 (there's big red lines on the plot showing rapid CTL rise sustained over extended periods).
The funny thing is that I've been showing that plot at seminars for several years now, but it was only when I was preparing my presentation for the '06 Cycling Summit that I noticed that the first rapid and sustained ramp-up in CTL was followed by a small dip. Sure enough, when I pulled out her training diary from that year, she'd missed several days of training due to illness...
(BTW, I belatedly realized that the particular slides that I was directing you to - i.e., the frequency distribution histograms - are already out-of-date. More recent versions based on additional data can be found in the 'Files' section of the wattage list, and/or in the version of this presentation hosted by Charles Howe on www.trainwithpower.net.)