CSSD Hydration Strategies 4 — Questions and Answers
Question 1: An athlete training twice daily in summer heat has a resting morning urine osmolality of 900 mOsm/kg for three consecutive days. What does this indicate?
- Optimal hydration from previous day's fluids
- Chronic mild dehydration requiring increased daily fluid intake (Correct answer)
- Kidney dysfunction requiring medical referral
- Normal hydration; osmolality fluctuates widely
Correct answer: Chronic mild dehydration requiring increased daily fluid intake
Consistently elevated morning urine osmolality above 700–900 mOsm/kg suggests incomplete recovery of fluid balance between training sessions.
Question 2: Which physiological adaptation from heat acclimatization most directly benefits hydration status during subsequent heat exposure?
- Decreased aldosterone secretion
- Earlier onset and increased sweat rate with lower sodium content (Correct answer)
- Reduced plasma volume
- Higher core temperature threshold for sweating
Correct answer: Earlier onset and increased sweat rate with lower sodium content
Heat acclimatization results in earlier onset of sweating, greater total sweat production, and lower sweat sodium concentration, improving thermoregulation while conserving electrolytes.
Question 3: A basketball player drinks 500 mL of a 6% carbohydrate sports drink 15 minutes before a game. What is the primary benefit regarding hydration?
- Maximizes liver glycogen stores before tip-off
- Ensures euhydrated state entering the game and provides a substrate reserve (Correct answer)
- Increases plasma osmolality to stimulate drinking during the game
- Reduces sweat rate during the first quarter
Correct answer: Ensures euhydrated state entering the game and provides a substrate reserve
Pre-game fluid intake ensures athletes begin exercise in a euhydrated state, optimizing cardiovascular function and thermoregulatory capacity from the outset.
Question 4: Which environmental condition MOST increases sweat rate for a given exercise intensity?
- Low humidity with high solar radiation
- High temperature combined with high relative humidity (Correct answer)
- High altitude with low ambient temperature
- Moderate temperature with strong headwind
Correct answer: High temperature combined with high relative humidity
High humidity impairs evaporative cooling, forcing greater sweat production to maintain thermoregulation even when air temperature may be moderate.
Question 5: When advising a team sport athlete about alcohol consumption the night before competition, what is the CSSD's primary hydration concern?
- Alcohol increases glycogen storage, impairing carbohydrate availability
- Alcohol's diuretic effect promotes dehydration that may persist into game day (Correct answer)
- Alcohol raises resting heart rate, increasing early-game fluid needs
- Alcohol enhances ADH release, causing fluid retention
Correct answer: Alcohol's diuretic effect promotes dehydration that may persist into game day
Alcohol inhibits ADH secretion, promoting diuresis and dehydration that can persist for hours, leaving athletes in a hypohydrated state before competition.
Question 6: A distance runner experiences muscle cramps late in a marathon. According to the exercise-associated muscle cramp (EAMC) dehydration hypothesis, what intervention is suggested?
- Immediate carbohydrate ingestion
- Sodium-containing fluid replacement to restore sweat electrolyte losses (Correct answer)
- Protein supplementation to repair muscle microtrauma
- Complete exercise cessation and ice immersion
Correct answer: Sodium-containing fluid replacement to restore sweat electrolyte losses
The dehydration/electrolyte hypothesis attributes EAMC to sodium and fluid deficits from sweat; sodium-containing beverages are the recommended intervention under this model.
Question 7: An athlete's post-exercise body weight is 1.8 kg less than pre-exercise after a 90-minute training session. Approximately how much fluid should be consumed to achieve full rehydration?
- 1.8 L (1:1 replacement)
- 2.5–2.7 L (approximately 150% of deficit) (Correct answer)
- 0.9 L (50% of deficit)
- 3.6 L (200% of deficit)
Correct answer: 2.5–2.7 L (approximately 150% of deficit)
Current guidelines recommend consuming approximately 125–150% of fluid losses (1.8 kg × 1.5 = ~2.7 L) to account for ongoing urine losses during recovery.
CSSD Hydration Strategies 4
An athlete training twice daily in summer heat has a resting morning urine osmolality of 900 mOsm/kg for three consecutive days.
What does this indicate?