1. Size of muscles: The strength of the muscle largely depends upon the size of the muscle. It is a well known fact that bigger and larger muscles can produce more force. The force produced by the same size of muscle in males and females is approximately the same but males are found to be stronger because they have larger muscles and bigger muscles in comparison to females.
2. Body weight: It is also a well known fact that the individuals who are heavier are stronger than the individuals who are lighter. There is a positive correlation between body weight and strength among international weightlifters. The heavier weightlifters lift the heavier weight. So, body weight also determines the strength of an individual.
3. Intensity of the nerve impulse: A muscle is composed of a number of motor units. The total force of the muscle depends on the number of contracting motor units. Whenever, a stronger nerve impulse from central nervous system excites more number of motor units, the muscles will contract more strongly or it can said that the muscle will produce more force or strength. So, the intensity of the nerve impulse also determines the amount of strength.
