Physical exercise and Yoga, when regularly done, have a positive effect on the body, as explained below.
Effects of physical activities on vital organs and body functions
Bones
Weight bearing exercise helps preserve bone mass and thus protects against osteoporosis (bone degeneration).
Muscles
Physical activity build and strengthen muscles, which can protect the bones from injury, support and protect joints from being affected by arthritis. Strong muscles also give stability and improve balance and coordination during movements. Physical activities also improve blood supply to the muscles and increase their capacity to use oxygen.
Muscles and muscle performance
Physical activities if undertaken regularly have beneficial effects on the muscular system. Whenever physical activities, games or sport are undertaken there is contraction of muscles and increase in energy level due to breakdown of ATP.
The beneficial effects of regular physical activities are listed below —
- Change in shape and size of the muscle fibres: Muscle fibres enlarge with physical activities which cause an overall enlargement of muscles with the change in its size and shape. The size of muscles increases by 60 per cent. It is because of this reason that, the muscles of arms of a tennis player are well developed.
- Maintenance of muscle tone: Muscles are stimulated to contract by signals from nerves. Due to continuous signals, when physical exercises are undertaken, muscles remain in partial state of contraction called muscle tone. Hence, regular physical activities maintain good muscle tone and enhance physical fitness.
- Increase in muscle proteins: The units of muscle contraction are proteins. Physical activities lead to increase in total proteins.
- Increase in blood capillaries: Regular physical exercises lead to increase in number of blood capillaries supplying blood to muscles.
- Increase in efficiency of ligaments and tendons: Ligaments and tendons become more efficient as a result of regular physical activity. This improves muscle movements resulting in greater tolerance of stress during strenuous activity.
- Long term increase in muscle strength: Regular physical exercises increase and maintain strength of muscles. This increases speed of contraction as in the case of marathon runner and also work well against load as in the case of weight lifter.
- Delay in muscle fatigue: Muscles need oxygen to contract. But when muscles are used for a long time during sport, available oxygen gets used up and lactic acid accumulates. This causes muscle fatigue. It is, therefore, important to do physical activities like stretching to delay muscle fatigue.
- Maintaining correct posture and beautiful body: Regular physical activities and yogic activity like asanas prevent postural deformities. Healthy muscles give the body a beautiful shape.
- Overall improvement in efficiency of muscle movements and reaction time: Muscles contract on receiving stimulus from nerves. The time taken to react to the stimuli (reaction time) improves with regular physical exercise.
- Increase in capacity for storage of food: Regular physical activities help cells to store more food, which can be readily available for oxidation to provide energy when needed.
Respiratory system
- Increase in size of lungs and volume of chest: Physical activities require more oxygen. Therefore, more oxygen has to be inhaled. This provides exercise to the lungs and chest and as a result the size increases. Simultaneously, the diaphragm and rib muscles strengthen.
- Increase in lung power: Respiratory exercises, which include Pranayam and Anulom-vilom, improve lung power. The efficiency of alveoli or air sacs of lungs also improves.
- Activation of unused (inactive) alveoli: Active inhalation increases residual volume of air, tidal air and vital capacity which is important for healthy body.
Circulatory system
Blood pumped into circulation transports oxygen and food to tissues, removes waste and also transports hormones to target organs. During physical activities, nutrients and Oxygen is needed by muscles to get energy for contraction. So heart pumps at a faster rate and circulation is speeded up. But this change is temporary. Certain permanent changes also occur when physical activities are undertaken regularly. These are given below.
Increase in the size of heart occurs as cardiac muscles develop with regular physical activities. Regular exercise increases the capacity and thickness of the walls of the heart.
Increase in number of capillaries and blood cells: The unused capillaries become active with physical activities making circulation efficient. An increase in the number of blood cells and amount of hemoglobin has also been observed.
Decrease in heart rate: Under normal conditions the heart beats 72 times per minute at rest. But an athlete’s heart rate may be found to be much lower at rest. The athlete’s heart becomes so efficient that at rest same requirement is fulfilled with fewer heartbeats.
Increase in stroke volume: Stroke volume is the quantity of blood pumped out by aorta in one stroke. Heart, having gained efficiency with regular physical activities, is able to pump out more blood in one stroke.
Decrease in LDL and increase in HDL: LDL and HDL are low density lipoproteins and high density lipoproteins respectively. Lipoproteins are secreted by liver. LDL, also known as bad cholesterol, adversely affects the blood vessels of the heart. On the other hand, HDL which is good cholesterol helps to remove cholesterol from the body. Regular physical activities help in production of more HDL and less LDL Thus physical activities help in reducing blood cholesterol.
Prevention of heart related illness/ailments: It is well known that cardiac diseases and high blood pressure can be prevented by regular physical exercises.
