Q.Explain any five physiological changes that occur in the human body due to ageing.

Ageing brings a gradual decline in the efficiency of nearly every body system. Here are five key physiological changes:

1. Decreased maximum heart rate and cardiac output. The heart's pacemaker cells become less responsive, and the left ventricle stiffens. Resting heart rate may stay normal, but the maximum heart rate achievable during exercise drops (roughly 220 - age). Stroke volume also falls, so cardiac output at peak effort is lower — this reduces aerobic capacity and endurance.

2. Loss of muscle mass and strength (sarcopenia). After about age 30, muscle fibres — especially fast-twitch (Type II) fibres — begin to atrophy. The rate of muscle protein synthesis slows, and motor units are lost. This leads to reduced grip strength, slower movements, and a lower basal metabolic rate because muscle is metabolically active tissue.

3. Reduced bone mineral density. Bone resorption outpaces bone formation, particularly after menopause in women due to oestrogen decline. Trabecular bone (spongy bone inside vertebrae and at the ends of long bones) thins first. The result is osteopenia and eventually osteoporosis, making bones more brittle and prone to fracture from minor falls.

4. Decline in lung function. The lung tissue loses elasticity, the chest wall becomes stiffer, and the respiratory muscles weaken. Vital capacity (the maximum amount of air that can be exhaled after a deep breath) decreases by about 40–50% between ages 20 and 70. Residual volume increases, so gas exchange becomes less efficient — maximal oxygen uptake (VO_2max) declines roughly 10% per decade after 25. …

Ageing is not a disease, but it does systematically reduce the body’s functional reserve. The physiological changes are gradual, cumulative, and vary from person to person based on genetics, lifestyle, and physical activity history. For a Physical Education student, knowing these changes is essential because they directly affect how we prescribe exercise intensity, duration, and type for elderly populations.

Here are five major physiological changes that occur with ageing:

1. Cardiovascular changes

The heart muscle becomes less efficient. Maximum heart rate declines (roughly 220 - age), stroke volume decreases, and the arteries lose elasticity, leading to higher systolic blood pressure. The result is a lower cardiac output during maximal effort, meaning the heart cannot deliver oxygen to working muscles as quickly as it once could. Recovery after exercise also takes longer.

2. Respiratory changes

Lung tissue loses elasticity, the rib cage becomes stiffer, and the respiratory muscles weaken. Vital capacity — the maximum amount of air you can exhale after a deep breath — drops by about 40–50% between ages 20 and 70. This reduces the body’s ability to take in oxygen and remove carbon dioxide, so older adults feel breathless more easily during exertion.

3. Muscular changes (sarcopenia)

After about age 30, muscle mass and strength begin a slow decline — roughly 3–8% per decade, accelerating after 60. This is called sarcopenia. Fast-twitch (Type II) muscle fibres atrophy more than slow-twitch fibres, so explosive power and speed are lost first. Reduced muscle mass also lowers basal metabolic rate, making weight gain easier and fat loss harder.

4. Skeletal changes (osteopenia and osteoporosis)

Bone mineral density peaks around age 30 and then gradually declines. In women, the drop accelerates sharply after menopause due to falling oestrogen levels. Bones become more porous and brittle, increasing the risk of fractures — especially in the hip, wrist, and spine. Loss of height and a stooped posture (kyphosis) are common visible signs.

5. Nervous system changes …