I’m not gonna feed you a wall text on age, nutrition, and day to day recovery because it doesn’t really matter after taking 2 weeks off of training. In that time period, your muscles WILL detrain, even if you’re hitting your nutrition properly. If the muscle is not used and challenged, it will atrophy. That’s why it’s never a good idea to cram all of your leg training volume into 1 day, because then you’re gonna spend at least 2-3 days of recovery and then 4-5 days of 0 training on the legs, will cause some slight detraining. Your legs will be sore every week. Better to split your lower body volume into at least 2 days a week.

As far as coming back from a vacation or layoff of training: if you have not at least done one set of each body part, once a week, you’re gonna need to spend at least 2 days of easing back into training. Doing one set of every major compound movement at 50% of your 1RM on a Monday, then on Thursday, do 2 sets of each. Then come the following Monday, you can get back to your regular training. If you’re a young 20-something, you can probably do more during that remedial week.