1.Your muscles grow when you rest. When lifting weights you are tearing muscle fibers. Rest days are crucial for these fibers to repair and become even larger. The strength is not being built during exercising, but on off days. When you are sore and body feel fatigue, it is important to listen to your body and make sure you get the rest you need. 

2. Rest days boost your motivation and drive.When you are fully rested and have fueled your body, your energy and motivation becomes even stronger. If you are at the gym everyday you may start to become used to the same routine.

3. Rest days aid joint health and help prevent future injuries. When lifting weights, it puts wear and tear on your bones that may cause inflammation. Inflammation is your body’s way of protecting itself from infection, illness, or injury. As part of the inflammatory response, your body increases its production of white blood cells, immune cells, and substances called cytokines that help fight infection That’s why it is crucial to rest and avoid this from happening.