Physiological Changes and Factors in Aging and Fitness

Physiological Changes Due to Aging

As we age, several physiological changes occur in our bodies. Here's a breakdown of the key changes:

Changes in the Nervous System

During aging, reaction and movement times slow down. The brain's weight, network size, and blood flow decrease.

Changes in the Gastrointestinal System

Aging leads to a reduction in the production of hydrochloric acid, digestive enzymes, and saliva. These changes can result in delayed stomach emptying and impaired swallowing. The breakdown and absorption of food may also be affected. The liver becomes less efficient in metabolizing drugs and repairing damaged cells.

Changes in the Urinary System

With age, kidney mass decreases, leading to reduced blood filtration. Bladder capacity decreases, and there's an increase in residual urine, raising the risk of urinary infections.

Changes in the Senses

As we age, senses like vision, hearing, taste, smell, and touch may become less acute. Vision and hearing are most affected. A reduction in taste buds can lead to a decreased interest in food.

Changes in the Respiratory System

Pulmonary function is impaired with advancing age. Airways and lung tissues become less elastic and efficient. There's a decrease in oxygen uptake and exchange.

Physiological Factors Determining Flexibility

Several physiological factors influence flexibility:

1. Muscle Strength: Muscles need a minimum level of strength to perform movements, especially against gravity or external forces.
2. Joint Structure: Different joints have varying ranges of motion. For example, the ball-and-socket joint of the shoulder has a greater range of motion than the knee joint.
3. Internal Environment: An athlete's internal environment affects flexibility. For instance, a warm bath increases body temperature and flexibility, while exposure to cold temperatures decreases them.
4. Age and Gender: Flexibility generally decreases with age but can be improved through training. Females tend to be more flexible than males.

Physiological Factors Determining Endurance

Endurance, a crucial component of physical fitness, is determined by these physiological factors:

Aerobic Capacity

Continuous activity requires a steady supply of energy to the muscles, which is provided in the presence of oxygen. The ability of an organism to maintain an adequate oxygen supply to working muscles is vital for endurance performance. Aerobic capacity depends on:

1. Oxygen Intake: This depends on vital capacity, influenced by lung size, the number of active alveoli, respiratory muscles, and chest cavity size.
2. Oxygen Transport: This relies on the amount of oxygen absorbed by the blood from the lungs and the circulatory system's ability to transport it quickly to the working muscles. Blood hemoglobin concentration, which can be enhanced through training, affects oxygen absorption. The heart's capacity, improvable through training, influences the transportation of oxygenated blood.
3. Oxygen Uptake: This is determined by the rate of diffusion, influenced by blood flow speed, temperature, and the partial pressure of oxygen and carbon dioxide in the blood and muscles. The number, size, and metabolic capacity of mitochondria, which can be improved through training, affect oxygen consumption.
4. Energy Reserves: Aerobic capacity depends on muscle glycogen and blood sugar levels, which can be enhanced through training.