The principal objective of this study was to test the hypothesis that acclimatization to moderate altitude (2,500 m) plus training at low altitude (1,250 m), 'living high-training low,' improves sea-level performance in well-trained runners more than an equivalent sea-level or altitude control. Thirty-nine competitive runners (27 men, 12 women) completed 1) a 2-wk lead- in phase, followed by 2) 4 wk of supervised training at sea level; and 3) 4 wk of field training camp randomized to three groups: 'high-low' (n = 13), living at moderate altitude (2,500 m) and training at low altitude (1,250 m); 'high-high' (n = 13), living and training at moderate altitude (2,500 m); or 'low-low' (n = 13), living and training in a mountain environment at sea level (150 m). A 5,000-m time trial was the primary measure of performance; laboratory outcomes included maximal O2 uptake (V̇O(2max)), anaerobic capacity (accumulated O2 deficit), maximal steady state (MSS; ventilatory threshold), running economy, velocity at V̇O(2max), and blood compartment volumes. Both altitude groups significantly increased V̇O(2max) (5%) in direct proportion to an increase in red cell mass volume (9%; r = 0.37, P < 0.05), neither of which changed in the control. Five-kilometer time was improved by the field training camp only in the high-low group (13.4 ± 10 s), in direct proportion to the increase in V̇O(2max) (r = 0.65, P < 0.01). Velocity at V̇O(2max) and MSS also improved only in the high-low group. Four weeks of living high-training low improves sea-level running performance in trained runners due to altitude acclimatization (increase in red cell mass volume and V̇O(2max)) and maintenance of sea- level training velocities, most likely accounting for the increase in velocity at V̇O(2max) and MSS.
ASJC Scopus subject areas
- Physiology (medical)