Explain the physiological mechanisms by which dehydration affects movement efficiency in athletic performance. (6 marks)
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- Cardiovascular function is compromised because blood volume decreases during dehydration. This leads to increased heart rate but reduced stroke volume per beat. As a result, oxygen delivery to working muscles is limited, causing decreased movement efficiency and earlier fatigue.
- Body temperature regulation becomes less effective due to reduced fluid availability for sweating. Internal temperature therefore rises rapidly during exercise. Consequently, the central nervous system is affected, which leads to reduced muscle activation and compromised motor control.
- Muscle function deteriorates as electrolyte imbalances, particularly sodium loss, occur. These imbalances disrupt normal contraction processes in muscle cells. Therefore, movements become less powerful and coordinated, resulting in inefficient biomechanics and wasted energy.
- Energy production efficiency declines because cellular processes are altered by dehydration. Glycogen stores subsequently deplete faster than normal. Hence, the body must rely on less efficient energy systems, which creates premature fatigue and reduced performance capacity.
- Movement coordination decreases when nerve signals are affected by dehydration. Poor proprioceptive feedback results in compromised technique execution. Consequently, athletes require more energy to perform the same movements, further reducing efficiency.
- Perception of effort increases significantly as various physiological stress responses are triggered. Athletes therefore feel movements are more difficult than normal. The outcome is unconsciously reduced intensity, which compounds the negative effects on performance.
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Sample Answer
- Cardiovascular function is compromised because blood volume decreases during dehydration. This leads to increased heart rate but reduced stroke volume per beat. As a result, oxygen delivery to working muscles is limited, causing decreased movement efficiency and earlier fatigue.
- Body temperature regulation becomes less effective due to reduced fluid availability for sweating. Internal temperature therefore rises rapidly during exercise. Consequently, the central nervous system is affected, which leads to reduced muscle activation and compromised motor control.
- Muscle function deteriorates as electrolyte imbalances, particularly sodium loss, occur. These imbalances disrupt normal contraction processes in muscle cells. Therefore, movements become less powerful and coordinated, resulting in inefficient biomechanics and wasted energy.
- Energy production efficiency declines because cellular processes are altered by dehydration. Glycogen stores subsequently deplete faster than normal. Hence, the body must rely on less efficient energy systems, which creates premature fatigue and reduced performance capacity.
- Movement coordination decreases when nerve signals are affected by dehydration. Poor proprioceptive feedback results in compromised technique execution. Consequently, athletes require more energy to perform the same movements, further reducing efficiency.
- Perception of effort increases significantly as various physiological stress responses are triggered. Athletes therefore feel movements are more difficult than normal. The outcome is unconsciously reduced intensity, which compounds the negative effects on performance.