Endurance Performance of Moderate Altitude Residents During Initial Exposure to 4300 M, With and Without Carbohydrate Supplementation
Abstract
This study determined the effect of living at moderate altitude on endurance exercise performance, with and without carbohydrate supplementation (CHOS), during the first 3 days of residence at 4300 m. The experimental trials were conducted in a double-blind manner. Subjects were healthy Air Force Academy (AFA) active duty members (9 men and 6 women; age: 30 +/- 30 yrs; mean +/- SE) who had been living at 1800 to 2200 m for at least 3 months prior to the start of the study. All performed a maximal effort 720 kJ cycle time trial at the AFA and at the summit of Pikes Peak (PP), CO, (4300 m) on Days 1 (PP1) and 3 (PP3). At the start of the time trials at PP, and then every 15 min thereafter, nine subjects drank a 10% CHO solution (0.175 g*kgEXP -1 body weight) and six fitness-matched subjects drank a placebo (PLA) solution. All subjects freely adjusted power outputs and drank water ad libitum. Blood glucose, heart rate, arterial oxygen saturation, and ratings of perceived exertion were recorded frequently during exercise. Cycle time did not differ between groups at the AFA (CHOS vs. PLA; 85 +/- 8 vs. 93 +/- 8 min), PP1 (101 +/- 8 vs. 116 +/- 10 min), or PP3 (95 +/- 8 vs. 107 +/- 12 min). For both groups, cycle times on PP1 and PP3 were longer compared to the AFA (P<0.01) and were improved from PP1 to PP3 (P<0.03). There were no between-group differences in any of the measurements during exercise, other than blood glucose (1.5 to 2.0 mmol*Lexp -1 higher for CHOS vs. PLA P<0.01). It was concluded that (1) moderate altitude residents had improved endurance performance from PP1 to PP3; (2) CHOS during exercise provided no additional performance benefit; and (3) endurance performance during initial exposure to 4300 m for moderate altitude residents was more than 50% better compared to previously studied low-altitude residents.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 30, 2005
- Accession Number
- ADA433424
Entities
People
- Allen Cymerman
- Beth A. Beidleman
- Charles S. Fulco
- Dennis Rufolo
- Ellen Glickman
- Janet Staab
- Kenneth Kambis
- Leonard Elliot
- Megan Hannon
- Michael Tapia
- Michael Zupan
- Paul B. Rock
- Stephen Muza
- Tamara Payn
Organizations
- United States Army Research Institute of Environmental Medicine