Accession Number : ADA192597

Title :   Hypothalamic-Pituitary-Adrenal Responses to Short Duration High Intensity Cycle Exercise,

Corporate Author : ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA

Personal Author(s) : Kraemer, William J ; Patton, John F ; Knuttgen, Howard G ; Marchitelli, Louis J ; Cruthirds, Charles

PDF Url : ADA192597

Report Date : Jan 1988

Pagination or Media Count : 32

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.

Descriptors :   *EXERCISE(PHYSIOLOGY), *MUSCLE FIBERS, ADRENAL GLANDS, ADRENOCORTICOTROPIC HORMONE, ANAEROBIC PROCESSES, BLOOD, BLOOD PLASMA, COMPUTER APPLICATIONS, CORTISOL, CYCLES, DENSITY, ERGOMETERS, HYPOTHALAMUS, INTENSITY, LACTATES, MORPHOLOGY(BIOLOGY), MUSCLES, MUSCULOSKELETAL SYSTEM, OXYGEN CONSUMPTION, PEAK VALUES, PITUITARY GLAND, SAMPLING, HUMANS, MALES, CAPILLARIES(ANATOMY), BLOOD CHEMISTRY, NONLINEAR SYSTEMS, LEGS, ENDURANCE(PHYSIOLOGY), RESPONSE(BIOLOGY)

Subject Categories : Biochemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE