OPTIMAL ALTITUDE FOR ???LIVING HIGH-TRAINING LOW???

Abstract

“Living high (2,500 m) û training low (1,250 m)” improves sea level performance in most endurance athletes. However, the individual variability in this improvement is marked, due at least in part, to a suboptimal erythropoietic response. We hypothesized that living at relatively higher altitudes would lead to greater increases in erythropoietin (EPO), VO2max, and sea level racing performance. Forty-eight competitive runners (32 men, 16 women) participated in: 1) 4 wk sea-level pretest period and supervised training camp; 2) 4 wk of “high-high-low” training camp where groups lived at 1,780 m, 2,085 m, 2,454 m, or 2,805 m and trained together at low to moderate altitude (high intensity workouts 1,250 û 1,780 m; base training 1,700 û 3,000 m) and 3) 2 wk of sea-level post-testing. Subjects were matched for gender, pre-altitude performance, and the percentage incrrease in EPO after 24 hours at a simulated altitude of 2,454 m in a hypobaric chamber and assigned to each living altitude in a balanced randomization. Primary outcome variables included VO2max and 3,000-m time-trial racing performance. Results: There was no difference among groups either for total training miles or number of hard interval sessions. VO2max increased after 4 weeks only at the three highest altitude exposures: 8 ± 85 ml; 206 ± 60 ml; 308 ± 60 ml; and 301 ± 73 ml respectively, with 2,085 m and 2,454 m statistically greater than 1,780 m. Both groups living at 2,085 m and 2,454 m improved 3,000-m time by 2.8 ± 0.7% and 2.7 ± 0.6% respectively; 15.7 ± 4.0 and 16.6 ± 4.2 seconds (p = 0.003 and 0.002) but 1,780 m and 2,805 m did not (1.1 ± 0.05% and 1.4 ± 1.1%; 6.3 ± 3.1 and 9.0 ± 7.1 s respectively). Conclusion: The optimal living altitude for “high-low” training appears to be 2,000 û 2,500 m. We speculate that < 1,800 m may be too low (possibly due to inadequate erythropoiesis) and ± 2,800 m may be too high due to negative aspects of altitude acclimatization.