Lifestyle Choices and Sedentary Living
Lifestyle and Its Impact on Health
The choices a person makes every day — what they eat, how much they move, how they sleep, whether they use recreational drugs — accumulate over time to shape their long-term health. These are known as lifestyle choices. Understanding which choices promote health and which ones damage it is fundamental to physical education because it connects the theory of the body to the reality of how people live. The spec identifies four key lifestyle factors: diet, activity level, work/rest/sleep balance, and the use of recreational drugs (alcohol and nicotine).
Diet
A balanced diet provides the energy and nutrients the body needs to function well. The key macronutrient proportions for a healthy, active individual are approximately 55–60% carbohydrates, 25–30% fats and 15–20% protein. Carbohydrates are the primary fuel for physical activity, particularly moderate-to-high-intensity exercise. Protein is essential for muscle repair and growth after training. Fats support hormone production, cell function and provide fuel for low-intensity, prolonged exercise. Vitamins and minerals (micronutrients) are needed in smaller amounts but support vital functions such as immune defence, oxygen transport (iron) and bone formation (calcium and vitamin D).
Poor diet choices can have serious long-term consequences. A diet consistently high in saturated fat and refined sugar raises low-density lipoprotein (LDL) cholesterol, contributing to atherosclerosis and coronary heart disease. A high-calorie, low-nutrient diet causes weight gain and, if sustained, leads to obesity. A diet lacking in calcium and vitamin D weakens bones, increasing the risk of osteoporosis. Insufficient iron intake can cause anaemia, reducing the oxygen-carrying capacity of the blood and impairing exercise performance.
Work/Rest/Sleep Balance
The body does not adapt to training during exercise — it adapts during rest and recovery. Insufficient sleep disrupts the release of growth hormone, which is essential for muscle repair. Chronically poor sleep is associated with weight gain (due to disrupted appetite hormones), increased injury risk and reduced concentration, which impairs the decision-making needed in sport. For athletes, 8–9 hours of sleep per night is generally recommended, though individual needs vary. An imbalanced lifestyle where work or social pressures chronically reduce sleep time can negate the benefits of regular training.
The four lifestyle factors are: diet (balanced nutrition vs poor food choices), activity level (regular exercise vs sedentary behaviour), work/rest/sleep balance (adequate recovery vs chronic sleep deprivation), and use of recreational drugs (abstaining vs smoking or alcohol use). Each factor can either protect health or increase risk of disease.
Recreational Drugs: Alcohol and Nicotine
Nicotine is the addictive substance in tobacco. Smoking damages the respiratory system progressively. The tar in cigarette smoke coats the alveoli, reducing the surface area available for gas exchange and lowering the efficiency of oxygen delivery to muscles. Carbon monoxide in smoke binds to haemoglobin in place of oxygen, further reducing the blood’s oxygen-carrying capacity. Long-term consequences of smoking include bronchitis (inflammation of the bronchi, causing persistent cough and breathlessness), emphysema (destruction of alveoli, causing severe breathlessness) and lung cancer. Smokers have significantly reduced cardiovascular endurance and are less able to sustain aerobic activity. A 16-year-old who smokes regularly will have measurably worse performance on a Cooper 12-minute run test than a non-smoking peer of the same training background.
Alcohol is a depressant drug that slows the central nervous system. Short-term effects relevant to sport include impaired reaction time, reduced coordination and decreased balance — all of which reduce performance and increase injury risk. Long-term excessive alcohol consumption damages the liver (cirrhosis), raises blood pressure, contributes to weight gain (alcohol is high in calories with no nutritional value) and weakens the immune system. Alcohol also disrupts sleep quality, compounding the recovery problems described above. Athletes who regularly consume alcohol in large quantities find that their cardiovascular fitness, strength adaptations and recovery rates all deteriorate over time.
Carbon monoxide from cigarette smoke binds to haemoglobin with an affinity 200 times greater than oxygen. This means a smoker’s haemoglobin is partially ‘blocked’ and cannot carry as much oxygen to working muscles. The result is that cardiac output must increase to compensate, raising heart rate for the same submaximal workload. The smoker’s maximum aerobic capacity (VO2 max) is measurably lower. Additionally, nicotine causes vasoconstriction — narrowing of blood vessels — which raises blood pressure and reduces blood flow to the working muscles. Naming the mechanism (carbon monoxide binds to haemoglobin; tar coats alveoli) earns more marks than simply stating “smoking reduces fitness.”
Sedentary Lifestyle and Its Consequences
A sedentary lifestyle is one that involves little or no regular physical activity. As a result of reduced energy expenditure, the body stores excess energy as fat, leading to being overweight or, in more serious cases, clinically obese. The consequences extend far beyond body weight. Without regular exercise, the cardiovascular system deteriorates: resting heart rate rises, blood pressure increases and the risk of coronary heart disease escalates significantly.
Sedentary individuals have lower insulin sensitivity, increasing the risk of type 2 diabetes. Inactivity weakens muscles through atrophy and reduces bone density, elevating the risk of osteoporosis. Posture deteriorates as postural muscles weaken from disuse, contributing to chronic back pain. Mental health is also affected: sedentary people have higher rates of depression and anxiety, partly because they miss the endorphin benefits of exercise and partly because sedentary activities (such as excessive screen time) displace social interaction and purposeful activity.
Students sometimes use these three terms interchangeably, but they have distinct meanings. Overweight refers to body mass above what is considered healthy for a person’s height (typically BMI > 25). Overfat refers specifically to excess body fat regardless of total weight — a heavily muscled athlete might be overweight by BMI but not overfat. Obese is a clinical classification (BMI > 30) associated with serious long-term health risks. The spec uses all three terms and the correct term for the context described is what earns credit.
Consequences of a sedentary lifestyle include: overweight/obesity, coronary heart disease, high blood pressure, type 2 diabetes, osteoporosis, loss of muscle tone and poor posture, and depression/anxiety. These span all three dimensions of health and are all reducible through regular physical activity.