How much % should we scale down intensity after every week of inactivity or rest?

I recall reading fitness drop around 5-10% every week of inactivity, is it correct?

I did just base work over the last 3 weeks and started back with butter yesterday @ 90% and plan to do the same with the other sessions until I do 4DP next week. I think it’s hard to say an exact % due to so many variables and if the drop is linear. Would a HM be an option to check where your at?

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5-10% sounds like a lot in 1 week?

I guess it depends how fit you were before the inactivity started, 5-10 might be for those who are beginners to training. I think if your in good physical shape you wouldn’t see a big drop for maybe 2 weeks and even then you may just find runs/rides slightly tougher but obviously the more weeks go by with no training whatsoever the more you will lose. Even if your doing very easy runs or rides your still doing something and it’s not so much detraining but recovery. After all I’m sure a lot of us don’t properly recover at all and train while still fatigued.


I drop zero % after 2 weeks off due illness. More than that, I see how I feel and dial it back. If I’ve been off for longer than a couple of months, I do a half monty and dial it back based on those results.

I’d suggest that the % you dial back will depend on more than duration off training. Age, life stress, and the fitness level you were at, plus how long you’ve been fit and training for, plus why you were off, travel, minor illness, I jury, major illness will all make a difference. I used to lose fitness way more quickly when I was new to cycling than now. The body does seem to remember. I find it easy to get back into the same intensity level after a short minor illness or things like being unable to train due to work. Injury and major illness, I’m definitely dialing it back.