Which is a known effect of dehydration on performance and how can athletes monitor hydration status?

• A. Dehydration reduces endurance and cognitive function; monitor via urine colour and thirst.
• B. Dehydration reduces endurance and cognitive function; monitor via heart rate alone.
• C. Dehydration has no effect on performance; monitor via thirst.
• D. Dehydration reduces endurance but does not affect cognitive function (monitor via urine colour and thirst).

Answer: (A)

Dehydration lowers both endurance and cognitive performance. When you’re not adequately hydrated, blood volume drops, heart rate rises, and temperature regulation becomes less efficient, which makes endurance tasks harder. It also impairs mental functions like attention, reaction time, and decision-making, which athletes rely on in competition.

Monitoring hydration in the field is practical and effective by checking urine colour and thirst. Urine colour gives a quick read on hydration status—the lighter the colour, the better hydrated; darker urine suggests dehydration. Thirst is a cue, but it isn’t always reliable on its own because you can become dehydrated before you actually feel thirsty, so using both signals together gives a better overall picture.

That’s why this option is the best: it pairs the known impact on performance with a sensible, easy-to-use monitoring approach.