Beta-endorphin, catecholamines, and cortisol during exhaustive endurance exercise.
To assess changes of beta-endorphin during intense endurance exercise, ten nonspecifically trained volunteers (aged 25.7 +/- 2.9 years) were subjected to an exhaustive endurance test on a cycle ergometer at the work load of the individual anaerobic threshold (IAT) determined in a preparatory graded exercise test. Prior to, in 25-min intervals during, and repeatedly subsequent to exercise venous blood samples were drawn to measure the levels of beta-endorphin (beta-E), cortisol (C), adrenaline (A), and noradrenaline (NA). In addition, lactate, heart rate, and rate of perceived exertion were determined. The levels of beta-E remained unchanged during the first 50 min; between the 50th and 75th min beta-E increased by 82% (p less than 0.01). At the end of the exercise (mean exercise time: 89 min), a beta-E level three times the resting level was measured. The maximum exercise-induced increase of beta-E showed a positive correlation to endurance capacity (W.kg-1 of IAT): r = 0.74; p less than 0.05. C exhibited similar changes to beta-E, but the onset of increase was delayed if compared with beta-E; there was a close correlation between these two stress hormones (75th min of exercise: r = 0.91; p less than 0.001). The catecholamines A and NA increased linearly during exercise, without a correlation with the behavior of beta-E being established.
Schwarz
L
L
Department of Sports and Performance Medicine, University of Saarland, Saarbrücken, FRG.
Kindermann
W
W
D000328:Adult; D001642:Bicycling; D004837:Epinephrine / Q000097:blood*; D015444:Exercise; D006339:Heart Rate; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008297:Male; D009638:Norepinephrine / Q000097:blood*; D010807:Physical Endurance; D005082:Physical Exertion; D013997:Time Factors; D001615:beta-Endorphin / Q000097:blood*
D007773:Lactates; D019344:Lactic Acid; D001615:beta-Endorphin; D006854:Hydrocortisone; D009638:Norepinephrine; D004837:Epinephrine