Physical Benefits and Consequences

This lesson covers the physical benefits of exercise and the physical consequences of inactivity, as required by the OCR GCSE PE (J587) specification. You must understand how regular physical activity improves the body's physical health and how a lack of activity leads to physical deterioration and increased disease risk.

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Physical Benefits of Regular Exercise

Regular physical activity produces a wide range of physical health benefits. The OCR specification requires you to know these benefits and be able to explain the mechanisms behind them.

1. Reduced Risk of Coronary Heart Disease (CHD)

Coronary heart disease is one of the leading causes of death in the UK. Regular exercise significantly reduces the risk.

How Exercise Reduces CHD Risk	Explanation
Lowers blood pressure	Exercise strengthens the heart, allowing it to pump blood more efficiently with less strain on blood vessel walls
Reduces LDL cholesterol	Exercise helps lower "bad" cholesterol, which forms fatty deposits (atheroma) in coronary arteries
Increases HDL cholesterol	Exercise raises "good" cholesterol, which helps remove fatty deposits from artery walls
Strengthens the heart muscle	Cardiac hypertrophy (the heart growing larger and stronger) makes each beat more efficient
Improves blood vessel elasticity	Regular exercise keeps blood vessel walls flexible, reducing resistance to blood flow

Exam Tip: When explaining how exercise reduces CHD risk, always include the mechanism. Do not just write "exercise reduces heart disease." Write "exercise reduces blood pressure by strengthening the heart muscle, meaning it can pump blood more efficiently with less force on the artery walls, reducing the risk of damage and fatty deposit build-up."

2. Reduced Blood Pressure

High blood pressure (hypertension) is a major risk factor for stroke, heart attack and kidney disease.

Term	Definition
Blood pressure	The force exerted by blood against the walls of blood vessels
Systolic pressure	The pressure when the heart contracts (pumps blood out)
Diastolic pressure	The pressure when the heart relaxes (fills with blood)
Hypertension	Persistently raised blood pressure (above 140/90 mmHg)

Regular exercise reduces blood pressure by:

• Strengthening the heart so it pumps more blood per beat (increased stroke volume), requiring fewer beats per minute
• Improving the elasticity of blood vessel walls
• Reducing the amount of body fat, which decreases the total amount of blood the heart needs to circulate

3. Improved Bone Density

Weight-bearing exercise (running, jumping, resistance training) stimulates bones to become denser and stronger.

Effect	Explanation
Increased bone mineral density	Weight-bearing forces stimulate osteoblasts (bone-building cells) to lay down more calcium and minerals
Reduced risk of osteoporosis	Higher bone density means bones are less likely to become brittle and fracture, especially in later life
Stronger skeletal support	Denser bones provide better structural support for the body and its muscles

This benefit is particularly important for young people (whose bones are still developing) and older adults (who are at higher risk of osteoporosis).

4. Obesity Prevention

Exercise plays a critical role in preventing obesity by increasing the amount of energy the body uses:

Concept	Explanation
Energy balance	The relationship between energy consumed through food and energy expended through activity and bodily functions
Weight maintained	When energy intake equals energy expenditure
Weight gain	When energy intake exceeds energy expenditure over time
Weight loss	When energy expenditure exceeds energy intake over time

Regular exercise increases energy expenditure, making it easier to maintain a healthy body composition. It also increases the body's metabolic rate, meaning more calories are burned even at rest.

graph LR
    A["Energy In<br/>(Food & Drink)"] --> B{"Energy Balance"}
    C["Energy Out<br/>(Exercise + Bodily Functions)"] --> B
    B -->|"Intake = Expenditure"| D["Weight Maintained"]
    B -->|"Intake > Expenditure"| E["Weight Gain / Obesity"]
    B -->|"Intake < Expenditure"| F["Weight Loss"]
    style D fill:#c8e6c9,stroke:#2e7d32
    style E fill:#ffcdd2,stroke:#c62828
    style F fill:#fff9c4,stroke:#f9a825

5. Reduced Risk of Type 2 Diabetes