How often should I take a rest day?

This really does depend on you and to be honest it is something you need to decide for yourself.

Recovery is a very individual process; some people will recover faster from a tough training session than others. To improve recovery, it’s important to consider sleep, nutrition, stress and stretching; optimizing these will reduce the number of rest days you’ll need between difficult training sessions.

Generally speaking, the body needs 24 to 48 hours to completely recover from a tough workout, but the way in which you recover can shorten or extend this.