EFFECT OF F1O2 ON PHYSIOLOGICAL RESPONSES AND POWER OUTPUT IN TRAINED CYCLISTS AT MODERATE ALTITUDE.

Abstract

PURPOSE: To evaluate the effect of different concentrations of inspired oxygen (F1O2) on physiological responses and power output in trained endurance athletes at altitude. METHODS: Subjects (n = 19) were trained male cyclists and triathletes (30 ± 7 yr; 177 ± 5 cm; 69.8 ± 9.8 kg; 9.1 ± 3.2 BF%; VO2max = 4.09 ± 0.52 L min−1, 58.7 ± 3.8 ml kg−1 min−1) who were residents of moderate altitude (1600–1700 m). Testing was conducted at 1860 m where subjects completed three trials in which they performed a standardized interval workout while inspiring a medical grade gas comprised of 21.0% (control), 26.5% or 60.0% O2. The interval workout consisted of 6 x 100 kJ performed on a cycle ergometer (Lode Excalibur™) at a self-selected load and pedaling cadence. Experimental trials were conducted at 7-day intervals in a randomized order and subjects were blinded to F1O2%. An average of the six work intervals was calculated, and a univariate repeated measures ANOVA was used to evaluate mean differences between trials. RESULTS: Major results are reported below as the mean ± SD. CONCLUSION: These data suggest that supplemental O2 (26.5% and/or 60.0% F1O2) produces significant improvements in Hb-O2 saturation and power output during intense interval training at moderate altitude, thereby allowing athletes to “live high-train low”. Supported by the United States Olympic CommitteeTable: No Caption Available