Lesson 04 · 3 min · 5 things to do
The dose makes the stressor
Predict when a load builds capacity and when it exceeds it.
A load that is too small does nothing. A load that is too large causes injury. What does that make the useful range?
- Yes.The same shape appears for training, heat, cold, fasting, sunlight and mental challenge. It is why 'is X good for you' has no answer without a dose.
- Not quite.Tolerance is measured on the day. The repair happens over the following days, and that is the limit that matters.
- Not quite.Below the band nothing adapts, and the capacity slowly falls. Doing nothing is a dose too.
Slide the size of the load and watch what it produces.
NoneModerateHeavyExtremeAdaptation gained−8Damage to repair0NoneNo demand, no signal. Capacity drifts downward — the body keeps what it uses.
Adaptation gained26Damage to repair10ModerateA clear demand, comfortably within repair. This is where nearly all the gains live.
Adaptation gained31Damage to repair34HeavyBigger demand, and repair is now most of the week. Gains are smaller than the effort suggests.
Adaptation gained12Damage to repair70ExtremeThe damage exceeds what can be repaired before the next demand. Capacity falls.
Between the moderate and heavy frames the effort rose sharply and the gain barely moved. What does that tell you?
- Yes.It is the same diminishing-returns shape as everywhere else, with a sting: the cost keeps rising in a straight line while the benefit flattens, so the last increment is nearly all cost.
- Not quite.The pattern is one of the better established in exercise physiology, and it is why serious plans are mostly moderate work.
- Not quite.The fourth frame is worse than the second in absolute terms, not just slower.
Move the control to see what changes.
The dose makes the stressor. Heat, cold, hunger, effort and difficulty all build capacity in a band and break it above one.
For each pair, which is the version that builds capacity?
A hard hour, then two days to recover.
A hard hour, every day, for a month.
A difficult problem you eventually solve.
A problem with no solution and no end date.
A cold shower.
Yes.Two features separate the columns: the load ends, and there is time before the next one. A demand with no end and no gap is the one shape that reliably exceeds capacity, whatever its size.A runner's capacity rises 4% after a well-recovered hard week, and falls 3% after an under-recovered one. Over eight weeks they manage five recovered weeks and three not. What is their net change, in percent?
%Yes.5 × 4 − 3 × 3. Adding percentages is a rough approximation here, and the shape is what matters: the under-recovered weeks did not merely fail to help, they removed gains already made.Why do two people doing an identical programme end up with opposite results?
- Yes.The body does not keep separate accounts for training, work, illness, worry and short nights. One programme, added to two different totals, sits in the band for one person and above it for the other.
- Not quite.Response does vary between people, and it is nothing like as large as the difference made by what else is on the pile.
- Not quite.Trying harder is the reflex, and where the total is already too high it moves the person further above the band, not back into it.
Lesson complete
Every load has a band: too little builds nothing, too much breaks what it built.
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