What happens to the body during exercise and how does it adapt to training over time?
The short-term (immediate) effects of exercise on the body and the long-term effects and adaptations that result from regular training.
A focused answer to AQA GCSE PE on the short and long-term effects of exercise: the immediate responses of the body to a single session, and the long-term adaptations of the muscular, cardiovascular and respiratory systems to regular training.
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What this dot point is asking
AQA wants you to describe what happens to the body immediately during a single exercise session (the short-term effects) and how the body adapts to regular training over weeks and months (the long-term effects).
Short-term effects of exercise
These are the immediate responses to a single bout of exercise:
- Increased heart rate to pump more oxygenated blood to the muscles.
- Increased breathing rate and depth to take in more oxygen and remove carbon dioxide.
- Increased body temperature and sweating to cool the body.
- Muscle fatigue and a build-up of lactic acid during anaerobic work.
- Redder skin as blood vessels near the skin widen to lose heat.
Each of these is the body meeting an increased demand. The working muscles need far more oxygen and produce far more carbon dioxide, so heart rate and breathing rise together to deliver oxygen and clear waste. The energy released by contracting muscles also produces heat, which is why core temperature climbs and the body sweats and reddens to lose that heat and protect itself from overheating. If the effort is intense enough to outstrip the oxygen supply, the muscles respire anaerobically, lactic acid accumulates, and the familiar burning fatigue sets in. These responses are temporary and return to normal within minutes to hours once the exercise stops, which is exactly what separates them from the lasting long-term adaptations.
Long-term effects and adaptations
These adaptations mean the trained body can deliver more oxygen, work harder for longer, recover faster, and resist injury better. A trained athlete also tolerates lactic acid better, so they can keep working anaerobically for longer.
The type of training shapes the adaptation. Resistance and strength training drives muscular hypertrophy and stronger tendons, suiting power athletes such as sprinters and throwers. Aerobic endurance training drives cardiac hypertrophy, a lower resting heart rate, more capillaries and a larger vital capacity, suiting distance runners and cyclists. This is the principle of specificity at work: the body adapts to the demands placed on it. Adaptations also follow reversibility, so a performer who stops training loses them over a few weeks (detraining), which is why athletes maintain a base level of fitness in the off season.
Worked example
Exam-style practice questions
Practice questions written in the style of AQA exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.
AQA 20173 marksDescribe three short-term effects of exercise on the body during a single training session.Show worked answer →
A Paper 1 recall item, one mark per correctly described immediate response.
Award marks for any three of: increased heart rate (to pump more oxygenated blood), increased breathing rate and depth (to take in more oxygen and remove carbon dioxide), increased body temperature and sweating (to cool the body), muscle fatigue, and lactic acid build-up during anaerobic work.
Markers reward immediate responses only. A long-term adaptation such as hypertrophy here would score zero because the question specifies short-term effects.
AQA 20204 marksExplain two long-term adaptations of the cardiovascular system to regular aerobic training and how each improves endurance performance.Show worked answer →
An AO2 question requiring named adaptations linked to performance.
Award marks for: cardiac hypertrophy (the heart muscle grows larger and stronger), which raises stroke volume so more blood is pumped per beat; and a lower resting heart rate (bradycardia), which shows greater efficiency. More capillaries also improve oxygen delivery to the muscles.
Full marks need the performance link: a higher stroke volume and more capillaries mean more oxygen reaches the muscles, so the performer sustains aerobic work for longer and recovers faster.
Related dot points
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Sources & how we know this
- AQA GCSE Physical Education (8582) specification — AQA (2016)