Practice IB Sports, exercise and health science (SEHS) Topic A.2.1 Water and Electrolyte Balance with authentic exam-style questions for both SL and HL students. This question bank focuses on the exact syllabus content for A.2.1 Water and Electrolyte Balance and mirrors Paper 1A, 1B, 2 style where relevant.
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Refer to the urine color chart. If an athlete’s urine consistently matches color D, what does this suggest about their hydration status?
What is the main effect of low sodium levels (hyponatremia) during endurance events?
Which electrolyte is most commonly recommended for replacement due to the greatest loss in sweat during exercise?
Why is sodium essential in maintaining fluid balance during exercise?
An ultramarathon runner drinks excessive plain water without electrolytes. Which condition is most likely to occur?
The athlete is optimally hydrated; electrolyte excretion is balanced
The athlete is slightly dehydrated; risk of hyponatremia is increased
The athlete is dehydrated; reduced plasma volume may impair thermoregulation
The athlete is overhydrated; antidiuretic hormone (ADH) is being suppressed
Headache and nausea
Muscle cramps and confusion
Dizziness and low blood pressure
Decreased sweat rate
Magnesium
Sodium
Potassium
Chloride
It stimulates sweat production to enhance cooling
It maintains osmotic balance and helps retain water
It is the main electrolyte inside cells and drives fluid into the cell
It promotes rapid glucose uptake into muscle independently of water movement
Hypernatremia
Hyponatremia
Hypoglycemia
Hyperthermia
