Summer holiday season is here, but there is no reason to worry about losing your hard gained muscle.
A recent study shows that when trained individuals take two weeks off from resistance training, they do not lose muscle. It is possible though that your muscles appear slightly smaller due to a decrease in muscle glycogen (carbs stored in the muscle), but this soon recovers quickly enough once you start training again. I would advise getting a session in if you’re lucky enough to be holidaying for more than three weeks!
Consistently train all year round so you have the luxury of having an enjoyable holiday.
A week or so off from training will actually do you good.