Increase in heart size: Regular exercises develop the muscles of the heart. It increases the size of the heart along with the strengthening of heart. The heart becomes efficient in doing its job.

The decrease in cholesterol level: Regular exercise reduces the level of cholesterol in Our blood. The level of cholesterol in our blood is directly linked with blood pressure. Exercise decreases the level of low-density protein and increases the level of high-density lips protein. It means that exercise decreases the LDL (bad cholesterol) and increase HDL (good cholesterol)

Faster adaptation to workload: Due to the regular exercise, the heart can adapt to working load quickly i.e. quick adjustment of the heart according to body needs.

Increase in no. and efficiency of capillaries: With the regular exercise, efficiency and no. of capillaries is increased with the increase of Muscle mass. The unused and new capillaries become efficient and nourish the various cells efficient and nourish the various cells effectively.

Improve the working capacity of the cardiovascular system: Regular exercise Improve cardio-vascular system thus the blood travels faster through the blood vessels and increased circulation of blood makes healing faster.

1. Muscle strength: The muscle should have a minimum level of strength to make the movement, especially against the gravity or external force.
2. Joint structure: There are different types of joint in the human body, some of the joints intrinsically have a greater range of motion than others for example. The ball & socket joint of the shoulder has the greatest range of motion in comparison to the knee joint.
3. Internal environment:- Internal environment of athlete influences the flexibility. For example-warm bath increases body temperature and flexibility whereas 10 minutes outside stay in 100c temperature reduces the body temperature and flexibility.
4. Injury: Injuries to connecting tissues and muscles can lead to thickening or fibronectin on the effected area. Fibrous tissues are less elastic and can lead to limb shortening and lead to reduce flexibility.
5. Age and gender: Flexibility decreases with the advancement of age. However, it is trainable. It can be enhanced with the help of training as strength and endurance are enhanced. Gender also determine the flexibility. Females tend to be more flexible than male.
6. Active and sedentary lifestyle: Regular activities enhance the flexibility, whereas inactive individual loses flexibility due to the soft tissues and joints shrinking and losing extensibility.
7. Heredity: Bony structures of joints and structure length and flexibilities of the joint capsules and surrounding ligaments are genetical and cannot be altered by stretching programs.

Speed is determined to a great extent by the genetic factors. The study of physiological Factors helps to select the activity for an individual.

1. The mobility of the Nervous System: The rapid contraction and relaxation of muscles are made possible by the rapid excitation and inhibition of the concerned motor centres. The nervous system can maintain this rapid excitation and inhibition for only for a few seconds. After which the excitation and inhibition for only for a few seconds. After which the excitation spread to the neighbouring centres causing tension in the entire body. This results in a decrease in speed. The mobility of the nervous can be trained only to a very limited extent.
2. Muscle composition: The muscle, which has more percentage of fast twitch fibre, contract with more speed in comparison to the muscle which has lower percentage be slow twitch fibre. The muscle position is genetical and cannot be changed by training.
3. Explosive strength: For very quick and explosive movements, explosive strength is indispensable. It depends upon metabolic composition, muscle size & muscle coordination. The explosive strength of the muscles can be improved through training.

Reduces the risk of Age-Related Dieses: Regular exercise reduces the risk of a number of health problems, many aged persons face. Such health problems are:

Reduces the risk of Age-Related Dieses: Regular exercise reduces the risk of a number of health problems, many aged persons face. Such health problems are cholesterol, increase good cholesterol, decreases blood pressure and blood vessels stiffness.

1. Increase in muscular strength: the Ageing process does not hinder the individual ability to enhance the muscle strength. Regular exercise increases the strength of the muscles. As a matter of fact, exercise increases the size of muscle which ultimately increases muscular strength.
2. Reduce the loss of muscle mass: Muscle mass decreases with advancing age. Ageing has a negative effect on metabolism. Regular exercise reduces the loss of lean body mass and drops in the metabolic rate. Regular exercise also reduces the accumulation of fats.
3. Enhances the capacity of lungs and hearts: Regular exercise enhance the working capacity of lungs and heart, it reduces the loss of electricity of the muscle fibres of lungs and heart. It also plays a key role in keeping the lungs strong and increase oxygen update and oxygen exchange.
4. Maintaining the bone density: The bone density decreases with age. It usually leads to fracture and osteoporosis. Physical exercise helps to maintain bone mass and stimulate bone growth. The ageing persons can increase their bone density with the help of regular exercise.
5. Slow down the brain due to ageing: The regular exercise reduces the risk of mild cognitive new nerve cells and builds new capillaries to supply the brain with more oxygen.
6. Improve mental health and mood: Regular physical activities can help to keep thinking learning and judgement skills sharpen. Aerobic and muscle strengthening activities can also reduce the risk of depression and may help to sleep better.

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.