Hypothalamic-Pituitary-Adrenal Responses to Short Duration High Intensity Cycle Exercise,
Abstract
Beta-endorphin (B-EP), adrenocorticotropin (ACTH) and cortisol plasma concentrations were examined before and after maximal exercise at four intensities (36, 55, 73 and 100% of maximal leg power (MLP) utilizing a computerized cycle ergometer. All intensities were greater than those eliciting peak oxygen uptake for the individual subjects. Blood samples were collected at rest, immediately following exercise (IP) and at 5 and 15 min post-exercise. Significant (p < 0.05) increases were observed at 36% MLP for B-EP and ACTH at IP, 5 and 15 min post-exercise. Plasma cortisol increased at 36% MLP at 15 min post exercise. Blood lactate significantly increased at all post-exercise collection points for exercise intensities of 36, 55 and 73% MLP and at 5 min post exercise for 100% MLP. B-EP concentrations at 36% MLP were significantly correlated (r=0.75) with capillary density (mm-2) and cortisol concentrations at 36% MLP were significantly correlated (r=0.89) with % type II muscle fibers. No other significant relationships were observed. Keywords: Beta endorphin, Adrenocorticotrophin, Cortisol, Blood lactate, Skeletal muscle fiber morphology, Anaerobic exercise.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1988
- Accession Number
- ADA192597
Entities
People
- Charles Cruthirds
- Howard G. Knuttgen
- John F. Patton
- Louis J. Marchitelli
- William J. Kraemer
Organizations
- United States Army Research Institute of Environmental Medicine