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Athletic performance and serial weight changes during 12- and 24-hour ultra-marathons
Wei-Fong Kao1, Chih-Ling Shyu, Xiu-Wu Yang
1Section of Emergency Medicine, National Yang-Ming University, Taipei, Taiwan. wfkao@vghtpe.gov.tw
Summary
Athletes in 12- and 24-hour ultra-marathons experience significant weight loss, primarily in the first 8 hours. Optimizing fluid intake early is crucial for maintaining body weight during these endurance events.
Area of Science:
- Sports Science
- Exercise Physiology
- Human Performance
Background:
- Ultra-marathon running involves prolonged physical exertion, leading to significant physiological challenges.
- Understanding body weight changes and dehydration is critical for optimizing athlete performance and health in extreme endurance events.
Purpose of the Study:
- To evaluate serial body weight changes in athletes participating in 12- and 24-hour ultra-marathons.
- To correlate these weight fluctuations with athletic performance, specifically the distance covered.
Main Methods:
- A prospective study design was employed.
- Fifty-two participants in a 12- or 24-hour ultra-marathon were monitored.
- Body weight was measured pre-race, at 4-hour intervals, and post-race.
Main Results:
- Significant body weight decreases were observed in both 12-hour (-2.89%) and 24-hour (-5.05%) races.
- The most substantial weight loss occurred within the first 4 hours of both races.
- Weight change was not correlated with performance in the 12-hour race but was positively associated with performance in the 24-hour race.
Conclusions:
- The majority of weight loss/dehydration happens within the first 8 hours of ultra-marathons.
- Fluid intake should be strategically optimized during the initial 8 hours for both race durations.
- An additional focus on fluid intake between 16-20 hours is recommended for 24-hour ultra-marathon runners.
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