Hey @jz91!
Detraining is a natural part of the training process. Minor detraining occurs during rest weeks or when tapering for an event, but it’s outpaced by the performance improvements that come with recovery.
More significant detraining occurs during the offseason, when a full recovery facilitates greater fitness improvements in the coming months. In these cases, detraining is temporary, intentional, and productive.
The detraining that comes with longer-term breaks from training, on the other hand, can be unproductive. Complete detraining can dramatically decrease your fitness with no real benefit, potentially erasing improvements you’ve worked long and hard to obtain. Luckily, it usually doesn’t take much to stave off these effects, and the fitter you’ve been in the past, the easier it is to bounce back.
Full info here: