How fast strength fades when training stops
Detraining is the partial reversal of fitness adaptations when the training stimulus is removed. For maximal strength the early picture is reassuring: a short layoff of one to a few weeks tends to preserve most of the gains, in part because much of strength is neural and the nervous system holds its learned coordination for a while. After that grace period strength declines gradually rather than collapsing.
The curve is therefore relatively flat at first, then slopes downward as the weeks accumulate.
Strength versus muscle size on different clocks
Strength generally fades more slowly than aerobic conditioning, which can decline noticeably within a couple of weeks. Compared with muscle size, the relationship is nuanced: neural strength can persist while measurable muscle cross-section also reduces only gradually, and previously trained muscle tends to regain size faster on return, an effect popularly called muscle memory.
Exact rates differ by individual, training history, age, and how complete the layoff is. This is general educational information; an injury-related break should be managed with a qualified professional rather than guided by a generic curve.