What important role does each play in an exercise regiment?

There are five principles of fitness out of which two are overload principle and rest and recovery principle. Overload principle is one of the most important principle which tell that to gain and improve the fitness one should do the hard work.  

Slowly and gradually the intensity and time of exercise are increased so that our body can adapt to the hard work. Overload principle plays an important role in improving the skills and improving performance during exercise and sports.

Rest and recovery principle is important to relax the body and release the stress that happens due to intense training like in case of weight lifting one day rest should be taken to repair and rebuild the muscles. This allows the body to encounter the fatigue and improve performance.

Explanation: