Training responses of plasma beta-endorphin, adrenocorticotropin, and cortisol.
The purpose of this study was to examine the effects of three different run training programs on plasma responses of beta-endorphin (beta-EP), adrenocorticotropin (ACTH), and cortisol to maximal treadmill exercise. Subjects were randomly assigned to one of three training groups: sprint intervals (SI) (N = 8), endurance (E) (N = 10), or combination (C) (N = 7). Training was monitored for 10 wk, and maximal treadmill exercise tests were administered pre-training and after 2, 4, 6, 8, and 10 wk of training. Blood samples were obtained (pre-training and after 10 wk) before, immediately after, and 5 and 15 min following the maximal exercise tests. All groups significantly (P less than 0.05) increased maximal oxygen consumption values at 8 and 10 wk of the training period. Significant exercise-induced increase in plasma beta-EP, ACTH, cortisol, and blood lactate were observed for both pre- and post-training tests in all training groups. The SI group demonstrated significant post-training increases in beta-EP, ACTH, cortisol, and 5 min post-exercise blood lactate concentrations in response to maximal exercise. No training-induced hormonal changes were observed for the E group. While exercise-induced increases were observed, the C group exhibited significant post-training reductions in plasma responses of beta-EP, ACTH, and blood lactate concentrations in response to maximal exercise. Still, resting and post-exercise increases in plasma cortisol concentrations were significantly higher in magnitude in the post-training test. Lactate was significantly correlated with beta-EP (r = 0.72), ACTH (r = 0.70), and cortisol (r = 0.64).(ABSTRACT TRUNCATED AT 250 WORDS)
Kraemer
W J
WJ
Exercise Physiology Division, U.S. Army Research Institute of Environmental Medicine, Natick, MA 01760.
Fleck
S J
SJ
Callister
R
R
Shealy
M
M
Dudley
G A
GA
Maresh
C M
CM
Marchitelli
L
L
Cruthirds
C
C
Murray
T
T
Falkel
J E
JE
D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000328:Adult; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D007773:Lactates / Q000097:blood; D019344:Lactic Acid; D008297:Male; D010101:Oxygen Consumption; D010806:Physical Education and Training / Q000379:methods*; D010807:Physical Endurance; D011897:Random Allocation; D012420:Running; D001615:beta-Endorphin / Q000097:blood*
D007773:Lactates; D019344:Lactic Acid; D001615:beta-Endorphin; D000324:Adrenocorticotropic Hormone; D006854:Hydrocortisone