The two ways by which a person can save the energy of the body is by increasing the muscular endurance and cardiovascular endurance.
Cardiovascular endurance can be defined as the ability to perform exercise at moderate level for an extended period of time. This helps to maintain the heart rate during running or exercise.
Muscular endurance can be defined as the efficiency of a muscle to sustain repeated contractions of muscles against a resistance for a longer period of time. It provides power and strength to the muscles.