Hydration and Performance in Young Triathletes During a Competition in Tropical Climate

Area of Science:

• Exercise Physiology
• Sports Science
• Environmental Physiology

Background:

• Understanding hydration and thermal regulation is crucial for athletic performance, especially in hot and humid conditions.
• Adolescent athletes participating in triathlons face unique physiological challenges during competition.

Purpose of the Study:

• To investigate fluid intake patterns in young triathletes during a tropical competition.
• To examine the relationship between body mass loss and athletic performance.
• To assess core body temperature changes in adolescent triathletes under competitive, tropical conditions.

Main Methods:

• Measured fluid intake and pre- and post-competition body mass in 35 adolescent triathletes.
• Monitored core body temperature in one male and one female participant.
• Analyzed urine specific gravity to assess hydration status upon waking.

Main Results:

• Athletes exhibited suboptimal hydration upon waking (urine specific gravity 1.024).
• Body mass loss averaged 0.6 kg, with 66% losing ≥1.0% and 29% losing ≥1.5% of body mass.
• Fluid intake (528.5 mL) replaced only 47% of estimated fluid loss (1184.9 mL); intake was higher during the run than the bike.
• Males showed a moderate negative correlation between body mass loss and finishing time (r = -.52), with higher sweat rates and faster times.
• Core body temperature increased to 40.1°C in the female and 39.6°C in the male participant.

Conclusions:

• Young triathletes in a hot/humid climate experienced mild to moderate dehydration and hyperthermia during competition.
• Despite the availability of fluids, hydration needs were not fully met, leading to significant body mass loss.
• While physiological strain was evident, participants did not develop symptoms of exertional heat illness.