Endurance Protocol With Moderate Altitude-acclimatized Athletes Post Live-high Train-low Intervention: A Pilot Study

Aerobic exercise performance is dependent upon an athlete’s VO2max, (i.e., ability to uptake, transport, and use O2). Live-High, Train-Low protocols have capitalized on adaptations to moderate altitude exposure (e.g., erythropoiesis) and the additional exercise intensity that is possible while simultaneously performing training in low altitude conditions to maximize all three components of VO2max. The preponderance of LHTL research has been performed on athletes who reside at low altitude; however, it is not known if the same benefits of LHTL will occur within athletes who have lived at moderate altitude for months prior. PURPOSE: Examining if a four-week LHTL intervention improves performance in previously altitude-acclimatized athletes. METHODS: Five moderate altitude acclimatized endurance athletes participated in a protocol consisting of six 4x4-minute intervals at 90-95% heart rate max (HR max) with 3-min active recovery (50-60% HR max) and six 47x15-sec intervals at 90-95% HR max with 15-sec recovery periods. Pre- and post-intervention measurements included VO2max, body composition via DEXA, hemoglobin, and hematocrit. RESULTS: Absolute VO2max did not significantly increase from baseline 3.28 ± 0.97 L/min to post 3.40 ± 0.91 L/min, (p = 0.13). Relative VO2max significantly increased from 46.56 ± 12.50 to 48.94 ± 12.14 mL/kg/min (p = 0.03). Body mass decreased slightly from 70.76 kg to 70.19 kg (p = 0.21), and lean mass increased by 0.43 kg (p = 0.58). Fat mass decreased from 15.87 kg to 14.88 kg, but this change was not significant (p = 0.16). Hematocrit and hemoglobin levels showed minimal changes, with hematocrit at 47.82% and hemoglobin at 16.26 g/dL post-intervention, both statistically non-significant. CONCLUSIONS: This pilot study suggests that the LHTL protocol may positively impact VO2max and lean mass in altitude-acclimatized athletes. Preliminary indications of potential endurance benefits for athletes competing at altitude, providing a foundation for future research with a larger cohort.