Carbohydrate supplementation and exercise performance at high altitude: a randomized controlled trial

Area of Science:

• Exercise Physiology
• Nutritional Science
• Altitude Research

Background:

• Acute carbohydrate intake enhances endurance at sea level and altitude.
• Chronic carbohydrate effects at altitude, where acclimatization may alter responses, are unknown.

Purpose of the Study:

• To investigate the impact of chronic carbohydrate supplementation on endurance exercise capacity and perceived exertion during high-altitude expeditions.
• To assess cardiovascular parameters and physical activity levels in response to carbohydrate supplementation at altitude.

Main Methods:

• A double-blind, placebo-controlled study involving 41 participants on a 22-day high-altitude expedition (5192m).
• Participants consumed either placebo or carbohydrate supplements via energy drinks ad libitum.
• Performance was assessed via a mountaineering time trial, with submaximal exercise tests and accelerometer data collected.

Main Results:

• Carbohydrate-supplemented individuals reported 18% lower ratings of perceived exertion during the time trial.
• They completed the mountaineering time trial 17% faster than the placebo group (p<0.05).
• No significant differences were observed in cardiovascular parameters or spontaneous physical activity between groups.

Conclusions:

• Chronic carbohydrate supplementation effectively reduces perceived exertion and enhances physical performance during high-intensity exercise at high altitude.
• These findings are particularly relevant for endurance activities and prolonged physical stress in hypoxic environments.
• The study highlights the benefits of sustained carbohydrate intake for mountaineers and high-altitude athletes.