How long until muscles start to shrink/weaken?

[exreds]

I would like to know how long will it take for muscles to start to weaken and/or shrink from not working out?

I'm asking because I'm going on holidays for 3 weeks. I'll be travelling a lot and probably won't have time to workout let alone find a gym.

Will those 3 weeks without working out be enough to notice a loss in strengh and muscle size?

I will obviously keep my diet in check (where possible) and keep my protein intake high.

Any input from your own experience will be greatly appreciated.

[dday39]

3 weeks will set you back a touch

do some pullups, chins, pushups

[exreds]

Yeah I'll try to squeeze in some exercise when possible. But it's gonna be difficult.

It's just that I've been working out really hard and gaining a lot of strenght lately, I'd really hate to see any big drawbacks in my progress.