The following informational summary was taken from The Journal of Medicine and Science in Sports and Exercise.
Author(s): SUBUDHI, ANDREW W.1; JACOBS, KEVIN A.2,3; HAGOBIAN, TODD A.2,4; FATTOR, JILL A.5; MUZA, STEPHEN R.6; FULCO, CHARLES S.6; CYMERMAN, ALLEN6; FRIEDLANDER, ANNE L.2
Issue: Volume 38(8), August 2006, pp 1425-1431
The purpose of the study was to investigate the effects of prolonged hypoxia and antioxidant supplementation on ventilatory threshold (VT) during high-altitude (HA) exposure (4300 m). While most of us will spend little to no time competing at or above 4300m (14,000ft) this study did show a positive benefit to those in the group that were supplied with the following regimen (daily for 21 days) of antioxidants:
- 12 mg of [beta]-carotene
- 180 mg of [alpha]tocopherol acetate
- 500 mg of ascorbic acid
- 100 µg of selenium
- 30 mg of zinc
The conclusion of the study confirmed what is already widely accepted and that is ventilatory threshold upon exposure to altitude decreases however it will improve upon acclimatization. The study went on to demonstrate that supplementing with the above stated regimen improved performance (decreased effect of exposure to high altitude on ventilatory threshold). This amount of improvement was measured at 9%.
In plain language, competing at altitude when not acclimated, limits your ability to perform. However, if you supplement with antioxidants, the negative effect of the altitude on your performance will be limited, ie you will perform better.