Energy intake deficit and physical performance at altitude

Area of Science:

• Sports Medicine
• Human Physiology
• Altitude Research

Background:

• Sea-level residents experience reduced physical performance at altitude.
• Acclimatization can partially restore performance, but the impact of nutritional status is unclear.

Purpose of the Study:

• To investigate the effect of a significant energy deficit on physical performance during high-altitude acclimatization.
• To determine if lean body mass loss impacts performance at altitude.

Main Methods:

• 10 men at 4300 m received a 1500 kcal/day deficit (DEF), while 7 maintained adequate intake (ADQ).
• Performance was assessed via VO2max, a lift and carry task, arm strength, and hand grip endurance.
• Body composition and performance were measured at sea-level and during 21 days at altitude.

Main Results:

• The DEF group lost 4.6 kg of lean body mass, while the ADQ group did not experience significant changes.
• Despite lean body mass loss, there were no significant differences in performance changes between the DEF and ADQ groups from day 3 to day 21.
• Both groups showed improvements in VO2max and the lift and carry task.

Conclusions:

• A significant loss of lean body mass due to underfeeding during the initial 21 days of altitude acclimatization does not impair physical performance.
• Nutritional strategies may need re-evaluation for optimizing performance during altitude exposure.