Deload weeks: why backing off makes the next block stick

A deload week is not a wasted week. It's the week where the work you already did becomes fitness.

Hard training does two things at once: it creates the stimulus to adapt, and it creates damage that has to be repaired. If you keep stacking stimulus before the repair catches up, you stop adapting and start digging a hole. The classic symptoms — flat legs, creeping resting heart rate, easy pace drifting slower at the same effort — are the body saying it's behind on the bill.

A deload is the planned payment. The usual prescription is one lighter week every four to six weeks of hard training, with volume dropped by roughly half and intensity held steady or eased back. You're not detraining — research shows the muscular adaptations you've already earned can be held for surprisingly long stretches of reduced work. What you're doing is letting the nervous system, connective tissue, hormones, and sleep all catch up so the next block has something to build on.

The mistake most intermediate runners make is treating the deload as optional and only taking one when they're already injured or sick. By that point you're not deloading, you're recovering. A scheduled step-back week is cheap insurance. A forced two-week layoff isn't.

The practical move: pick week four (or six, depending on your block length) and write it into the plan before the block starts. Same easy runs, same strides if they're already in your week, but cut the long run, drop one workout, and skip any double days. Then look at the data after — easy pace at the same heart rate, sleep, mood. That's the signal to start the next block.

Source: ScienceAlert — The Science of Deload Weeks