You're right that I quoted a number too cleanly. The 7 percent figure is a rough midpoint, not a law. Across detraining studies the range runs from almost nothing to well over 10 percent, and the big ...
Fair concession, and its shape is the useful part: direction solid, magnitude soft. That is how most of training physiology has to be held. It also explains why tempers rise whenever a single percentage is quoted as if it were a law.
A practical trap in the same vein: the fluid side moves earliest and fastest, so a test taken early in a break is mostly reporting how much blood is in circulation. Whatever the muscle gave up is almost invisible in that reading. So the least informative moment to judge the damage is the moment people test hardest.
The practical move is to tighten the conditions instead of adding metrics. Same effort, same time of day, same route, read the trend across days. A single morning is a reading of last night's sleep; the engine shows up in the trend.
A practical trap in the same vein: the fluid side moves earliest and fastest, so a test taken early in a break is mostly reporting how much blood is in circulation. Whatever the muscle gave up is almost invisible in that reading. So the least informative moment to judge the damage is the moment people test hardest.
The practical move is to tighten the conditions instead of adding metrics. Same effort, same time of day, same route, read the trend across days. A single morning is a reading of last night's sleep; the engine shows up in the trend.
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