Hard Is Only Hard in Context

A training log records how much you did. It cannot tell you whether that was a lot, because the same session is routine for someone training consistently and a significant overreach for someone back from two weeks off. The acute:chronic workload ratio, meaning recent work divided by habitual work, supplies the missing context by comparing the last 7 days against the last 28: what you just did, against what your body is actually conditioned for. A ratio near 1.0 means this week resembles your recent normal. The sports science literature associates roughly 0.8 to 1.3 with the lowest injury rates and sharp spikes above it with the highest.

Two honest caveats. The relationship is correlational, and the method has drawn real methodological criticism over how the windows are constructed and what they can support, so this is framed throughout as something worth noticing, never a rule. And a planned hard week is *supposed* to read high; that is what progressive overload looks like from the outside. Kriterion counts rest days as part of the window rather than averaging only over days you trained, since a rest day is genuinely part of a training load, and excludes passive step activity, which would otherwise add a large constant to both windows and flatten everyone toward 1.0.