Tapering

A taper works the same fitness-fatigue relationship that Form describes. Once volume drops, Fatigue clears much faster than Training Load, so the fitness underneath re-emerges without you adding anything new. A good taper is not a rest week. Sessions stay sharp and race-pace-specific, only shorter and less frequent, which preserves fitness and neuromuscular sharpness while the tiredness drains off.

Bosquet et al.'s 2007 meta-analysis of tapering research, published in Medicine & Science in Sports & Exercise, is the most cited synthesis on the subject. It found the biggest performance gains came from a progressive, exponential cut in volume of roughly 40 to 60% over about two weeks, with training frequency and intensity largely maintained. An abrupt single drop, the step taper, did worse than the gradual version in the pooled data.

The Bosquet meta-analysis put the mean performance gain from a well-executed taper at roughly 2 to 3%, against carrying normal training into the race. That is a large margin in competitive racing. Individual response varies with training history, and with how much fatigue you were actually carrying when the taper started.

Taper length and depth should scale with the race and with the block behind it. Marathon tapers usually run two to three weeks, 5K and 10K tapers one to one and a half, because marathon training leaves more accumulated fatigue to clear. And a taper is only worth as much as the fitness banked under it. It converts Training Load into race-day performance. It does not create fitness.

Cutting intensity along with volume does the most damage. The Bosquet data specifically supports holding intensity while volume comes down, and dropping both tends to produce detraining rather than freshness. Tapering too long or too deep is the other one, and it leaves Form so high that race day feels flat instead of fast.