So I recently got back from a trip to Mexico and admittedly I made it to the gym all of once. Sure enough, one of the first things I read when I get back is this article on detraining.
The biggest thing that I took from reading this was that for hypertrophy there was mixed evidence as to how long before breakdown begins. Even with mixed evidence you can assume 2 weeks before you need to even begin to think about it being a problem. But the catch here is that body water and glycogen may give the appearance that you have “lost size,” but really it’s just your muscles not remaining full of glycogen.
Strength gain loss did not happen within 3 weeks of detraining.
But the real point I want to get across is that taking 2-3 weeks off of a CONSISTENT training routine isn’t going to set you back as much as you might feel it does. Now I’m not saying take 2-3 weeks off every month here, I’m just saying don’t sweat it if you have been very consistent in your training and then take a week or two off.
Some evidence even says that after this time off the gains you make when you come back are even better! So maybe a little time off a few times a year could be beneficial!
Heck, even Arnold said in his encyclopedia of bodybuilding that every 8 weeks you should take 1 weeks off.
But I encourage you to read the link above and make your own conclusions for your training!