Changes in Body Composition and Aerobic Capacity after High Altitude Exposure in Elite Climbers

Abstract

BACKGROUNDHigh altitude (HA) exposure influences appetite, protein synthesis and breakdown, and aerobic capacity. Thus, HA exposure typically causes weight (wt) loss, while the impact on aerobic capacity upon return to sea level is more variable.OBJECTIVETo examine the influence of hypobaric hypoxia on body composition and exercise capacity in elite HA climbers (n=4, 2 female) acclimating at ≥5,150 m over 2 mo. relative to trekkers (n=8, 0 female) acclimating at 5,150 m over 2 wks (Mt. Everest, Nepal). Each elite climber successfully summited Mt. Everest.METHODSBody composition (DEXA, skin folds, wt) and exercise capacity (treadmill) were assessed before and within 2 wks post HA.RESULTSHA exposure increased Hct and Hb, with peak values of 52±5% and 18±2 g/dl, and 50±3% and 17±1 g/dl for the climbers and trekkers, respectively. HA decreased lean and fat tissue in both the climbers (lean −4.4±2.3%, fat −8.2±4.0%) and trekkers (lean −1.8±1.6%, fat −5.8±6.1%) (all P≤0.06). No change was observed in skin folds for either group. Wt decreased in the climbers (−5±2%, P<0.03) and trekkers (−3±1%, P<0.01). There was no change in VO2max pre‐to post‐HA in either group (climbers 3.26 ± 0.37 vs. 3.27 ± 0.61 L/min; trekkers 3.60 ± 0.54 vs. 3.66 ± 0.43 L/min).CONCLUSIONHA results in both lean and fat tissue loss in well acclimatized climbers and trekkers with little subsequent impact on aerobic capacity. Mayo Clinic & TNF.