Effects Of Ischemic Preconditioning On Adaptations To An Altitude Training Camp In Well-trained Cross-country Skiers

Acclimatization and training at moderate altitude (“live high-train high” paradigm) has been shown to improve sea-level endurance performance in athletes. PURPOSE: To assess whether ischemic preconditioning (IPC) performed prior to an altitude training camp could further enhance maximal aerobic physiology and performance. METHODS: In a randomized controlled trial, nineteen competitive cross-country skiers (8 women; group VO2peak 71.2±9.3 ml.kg-1.min-1) performed 6 sessions of IPC (4x5-min occlusions to both legs at 110% arterial occlusion pressure, n=10) or placebo compressions (30% arterial occlusion pressure, n=9) over 7 days immediately before attending a 21-day altitude camp in Park City, Utah (2,200 m) during their pre-competition season. All athletes were from the same team and performed the same supervised training sessions before and during the camp. Primary measure of performance and laboratory outcomes included a 3,000-m track time trial, peak treadmill speed and peak O2 uptake. Freshness/fatigue state was assessed with the Hooper-MacKinnon questionnaire. RESULTS: The change in fatigue state over the camp was similar between groups. VO2peak improved only in IPC (3 ml.kg-1.min-1, 4%, P=0.02). The time to exhaustion in the incremental test also only improved in IPC (15.5 sec, P=0.007), in direct proportion to the increase in VO2peak (r=0.84, P<0.05). The peak treadmill speed improved in IPC (1.1 km.h-1, P=0007) and PLA (0.8 km.h-1, P=0.004), as well as the time to complete the 3,000-m time trial (IPC: 10:32 to 10:27 min:sec, P=0.007; PLA: 10:24 to 10:19 min:sec, P=0.01), without group differences. CONCLUSION: Chronic IPC application enhances the VO2peak gain from an altitude training camp in well-trained skiers, concomitant with a longer time to fatigue. However, the improvement in sea-level running performance does not appear to be majorated by a prior ischemia-reperfusion stimulus in a “live high-train high” paradigm. Ski de Fond Québec