Beta-endorphin time course response to intensity of exercise: effect of training status

Saved in:
Bibliographic Details
Title translated into German:Reaktion der Zeitkurve des beta-Endorphins auf die Intensitaet der koerperlichen Belastung: Auswirkung des Trainingszustandes
Author:Goldfarb, A.H.; Hatfield, B.D.; Potts, J.; Armstrong, D.
Published in:International journal of sports medicine
Published:12 (1991), 3 , S. 264-268, Lit.
Format: Publications (Database SPOLIT)
Publication Type: Journal article
Media type: Print resource
ISSN:0172-4622, 1439-3964
Online Access:
Identification number:PU199112050541


The concentration of beta-endorphin (B-EP) was measured in 6 trained and 6 untrained cyclists during three intensities of exercise to determine the time course changes of B-EP. B-EP was determined by radioimmunoassay with <5 cross reactivity with beta-lipotrophin. A counter-balanced design was used to avoid an order effect from exercise intensity. Resting B-EP values were similar across visits. There were no differences in resting B-EP values comparing the trained (4.61 +/- 0.25 pmol/l) to the untrained (4.03 +/- 0.23) pmol/l) group. Cycling at 60 VO2max did not increase B-EP in either group at any time measured. Cycling at 70 VO2max increased B-EP by 10 min in both groups p<0.05. The rate and magnitude of increase of B-EP were similar for both groups. B-EP changes at 80 VO2max were significantly greater that at 70 VO2max and were identical for the two groups. Both groups demonstrated increases by 5 min and further increases at 30 min of exercise p<0.01. These changes occurred despite the fact that lactate levels were lower in the trained group at both 70 and 80 VO2max intensities. It is concluded that the time course change for B-EP is similar for trained and untrained individuals working at the same relative intensity of exercise and does not seem to be related to plasma lactate concentrations. Verf.-Referat