Altitude Acclimatization Attentuates Plasma Ammonia during Submaximal Exercise,
Abstract
This study examined the effects of acclimatization to 4300 m altitude on changes in plasma ammonia concentrations with 30-min submaximal (75% VO2 max) cycle exercise. Human test subjects were divided into a sedentary (n=6) and active group (n=5). Maximal oxygen uptake (VO2 max) was determined at sea level, after acute HA (t24h) and chronic HA (t=13d), exposure to 4300 m altitude. The VO2 max of both groups decreased 32% with acute HA when compared to sea level. In the sedentary group, VO2 max was decreased an additional 16% following 13-days continuous residence at 4300 m, while VO2 max in the active group showed no further change. Plasma ammonia concentration increased (P0.05) over resting levels immediately following submaximal exercise during sea-level and acute HA exposure in both groups. Immediately following submaximal exercise at chronic HA, the active group showed no increased plasma ammonia accumulation, whereas the post-exercise ammonia in the sedentary group was elevated but to a lesser ex tent than sea level or acute HA. Thus, post-exercise plasma ammonia concentration is decreased with altitude acclimatization when compared to exercise performed at the same relative intensity at sea level or acute HA. This decrease in ammonia levels may contribute to enhanced performance and altered substrate utilization with exercise following acclimatization to altitude. Keywords: Plasma lactate; Insulin; and Glucose.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1986
- Accession Number
- ADA168630
Entities
People
- Charles S. Fulco
- Laurie A. Trad
- Particia M. Young
- Paul B. Rock
- Vincent A. Forte Jr.
Organizations
- United States Army Research Institute of Environmental Medicine