Exercise is a huge and necessary stress for the human body. Exercise and recovery, when combined appropriately, strengthen the body. One without the other is not ideal. Exercise also lengthens lifespan and healthspan. For your body to adapt to the stress of exercising, your muscles need to repair themselves. If you do not build in recovery stretches and rest days your body is going to get more and more exhausted which will eventually lead to injury. Another consequence of poor recovery is a lack of gains in muscle strength, hypertrophy or power.

During exercise, you are systematically using muscle and inducing signals at the genetic level that cause certain proteins to be formed. Recovery periods allow your muscles to heal and gradually strengthen to the stresses put upon them during exercise. The protein formation and the adaptation of the muscle group starts after exercise and will continue for a few days actually. Muscle protein synthesis is elevated by about 50% at 4 hours after a resistance training session. It goes on to double at 24 hours and then gradually returns to normal. Without recovery, your body is extremely unlikely to progress to longer and harder exercise routines. You may even have to set back from the difficulty level you were already at.

If there is any micro-tearing of the muscle or fascia elements too, these must have time to repair.