Thermoregulation during Cold Water Immersion is Unimpaired by Muscle Glycogen Depletion
Abstract
This investigation studied the importance of muscle glycogen levels for body temperature regulation during cold stress. Physiological responses of eight euglycemic males were measured while they rested in cold water on two separate occasions. The trials followed a three-day program of diet and exercise manipulation designed to produce either high (EMG) or low (LMG) pre-immersion glycogen levels in the muscles of the legs, arms and upper torso. Pre-immersion vastus lateralis muscle glycogen concentrations were lower during the LMG trial than the HMG trial. There were no significant differences between the two trials in shivering as reflected by aerobic metabolic rate or in the amount of body cooling as reflected by changes in rectal temperature during the immersions. Post-immersion muscle glycogen levels remained unchanged from pre-immersion levels in both trials. Small but significant increases in plasma glucose and lactate concentration occurred during both immersions. Plasma glycerol increased during immersion in the LMG trial but not in the HMG trial. Plasma free fatty acid concentration increased during both immersion trials, but the change was apparent sooner in the LMG immersion. It was concluded that human thermoregulatory response to cold stress is not impaired by a substantial reduction in the muscle glycogen levels of several major skeletal muscle groups.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1988
- Accession Number
- ADA199203
Entities
People
- Andrew J Young
- Michael N. Sawka
- P. D. Neufer
- Stephen R. Muza
Organizations
- United States Army Research Institute of Environmental Medicine