Question

Explain the physiological factors determining strength.

Answer 1

Strength is the ability of muscles to produce force in single and maximal effort. This depends upon the following physiological factors. 

(a) Muscle cross-sectional area: It is generally measured with girth measurement. The muscle having bigger cross-section area has more strength because larger muscles have better quality of action and myosin filaments. 

(b) Types of muscle fibre: There are two basic types of fibres. 

(i) Slow twitch fibres 

(ii) Fast twitch fibres. 

Fast twitch muscle fibres lead to increase in muscle size and strength with greater explosive power. Every individual has different ratios of slow and fast twitch muscle fibres. 

(c) Muscle length: Persons with relatively long muscles have greater potential for developing size and strength than person with relatively short muscles. 

(d) Age and gender: Muscle strength declines with age due to decrease in muscle cross-sectional area. The strength changes with increase in age specially after 15 years. Men and women have similar tissues but men have bigger muscle size leading to better strength as compared to women. 

(e) Nerve impulses: Your brain and nervous system have the power to activate more motor units when they need to generate a large amount of force. So nerve impulses, intensity and the number of motor units determine the muscular strength.

Answer 2

1. Muscle size: Muscle strength directly depends on the cross-sectional area of muscle. It is well known that bigger and larger muscle can produce more force. The force produced by the same size of muscles in males and females is approximately the same but males are found to be stronger because they have larger and bigger muscles in comparison to females.
2. Body weight: There is a positive correlation between the body weight and strength individuals with than heavier body weight are stronger than the individual with the lighter weight.
3. Muscle composition: The muscle composition is genetically determined and can not be changed by any type of training.
4. Nerve impulses: The nervous system also plays a role in muscle strength. The brain and nervous system have the power to activate more motor units when they need to generate a larger amount of force. Through the strength training, the body learns to recruit more motor units and increase these units.
5. Age and gender: Age and gender is a factor which effects the muscle strength. Muscle strength decline with the age but it is primarily due to a decrease in muscle cross-sectional area and a decline in the number of contractile tissues within the muscle fibres. Regular strength training limits loss of muscle strength with ageing. Men have greater absolute muscle strength than women.