Journal Title (Medline/Pubmed accepted abbreviation): Eur J Nutr
Page numbers: 285-292
doi (if applicable):
Hypothesis: The hypothesis was that antioxidant status is impaired by 18 days of “living high, training low” (LHTL) and will remain altered after 14 days of recovery.
Subjects: A total of 11 elite cross-country skiers were the subjects in this study. There were 6 in the treatment group (3 male, 3 female) and 5 (2 male, 3 female) in the control group. Subjects were not taking antioxidant supplements during training and recovery periods.
Experimental design: Independent groups (no crossover), subjects were matched on VO2 max upon assignment to treatment groups.
Treatments and protocol: Following pre-testing, the subjects in the treatment group trained for 2 hours per day in a camp at Prémanon, France (altitude 1,200 m) for a period of 18 days. During this period, their resting and sleeping periods were spent at a simulated higher altitude in a controlled chamber in which normobaric poikilocapnic hypoxia was achieved. The chamber was set to simulate 2,500 m for the first 6 nights, then 3,000 m for 6 nights and 3,500 m for 6 nights. Oxygen saturation of the athletes was monitored for safety. The control group performed the same training routine in the same location with no hypoxia. Following the training period, all subjects recovered for a 14-day period at 1,200 m. Blood sampling was done at pretest and at days 1 (POST1) and 14 (POST14) posttraining for various markers of oxidative status and levels of antioxidant nutrients such as vitamin E, vitamin A, lycopene, and b-carotene.
The authors showed that for some markers of antioxidant status, even 14 days of recovery at lower altitude was insufficient to return these markers to the levels observed before exposure to higher altitude occurred. The authors postulated that perhaps the dietary intake of antioxidant nutrients was insufficient to compensate for the oxidant stress induced by altitude and training in these athletes. Further studies are required to examine if supplementation of antioxidant nutrients in such athletes will prevent these declines in antioxidant status.