Impact of prolonged exercise in the heat and carbohydrate supplementation on performance of a virtual environment task

Mil Med. 2008 Feb;173(2):187-92. doi: 10.7205/milmed.173.2.187.


Purpose: The purpose of this investigation was to determine whether performance of a virtual environment (VE) task is influenced by exercise in the heat and carbohydrate supplementation.

Methods: Ten males completed four exercise trials to fatigue. During each trial, subjects cycled at a submaximal workload. Subjects exercised in a normal environment (NORM) and in a hot environment on different occasions. During exercise, subjects drank 10 mL x kg(-1) x hour(-1) of body weight of a 6% carbohydrate beverage (CHO) or a placebo. Subjects completed a VE task before, during exercise, and after fatigue.

Results: More failures occurred during placebo than CHO during exercise. The NORM CHO trial had the fewest failures at fatigue. More kills occurred during exercise in the NORM CHO.

Conclusions: Performance of a VE task was negatively influenced by prolonged exercise and heat stress. CHO supplementation may have a positive impact on performance of the VE task following prolonged exercise.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Adult
  • Dietary Carbohydrates / administration & dosage*
  • Exercise / physiology*
  • Exercise Test
  • Hot Temperature / adverse effects*
  • Humans
  • Male
  • Monitoring, Physiologic / methods
  • Physical Endurance / physiology
  • Placebos
  • Task Performance and Analysis
  • United States


  • Dietary Carbohydrates
  • Placebos