title: Plasma beta-endorphin immunoreactivity: response to resistance exercise.
abstract: Previous research investigating the response of plasma beta-endorphins (beta-EP) to resistance exercise has resulted in equivocal findings. To further examine the effects of resistance exercise on beta-endorphin immunoreactivity, six resistance-trained athletes participated in a three-set series of eight repetitions of isotonic exercise. All exercises were performed at 80% maximal effort. Blood was sampled from the group by venepuncture, both prior to and following the exercise bout, and beta-endorphin concentration was determined by radioimmunoassay. The results indicated that mean (+/- S.E.) plasma levels of beta-endorphins following exercise (18.04 +/- 3.4 pg beta-EP ml-1) were not significantly changed from pre-exercise (control) levels (19.59 +/- 2.4 pg beta-EP ml-1), although there was considerable inter-individual variability. Our results support previous research which has reported no significant changes in beta-endorphin immunoreactivity following resistance exercise, as well as reported findings of considerable variability in the beta-endorphin response to exercise.
authors.affiliation: Department of Health and Sport Science, Robins Center, University of Richmond, Virginia 23173.
authors.forename: E F
authors.initials: EF
authors.lastname: Pierce
authors.forename: N W
authors.initials: NW
authors.lastname: Eastman
authors.forename: H T
authors.initials: HT
authors.lastname: Tripathi
authors.forename: K G
authors.initials: KG
authors.lastname: Olson
authors.forename: W L
authors.initials: WL
authors.lastname: Dewey
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D011863:Radioimmunoassay; D014891:Weight Lifting / Q000502:physiology*; D001615:beta-Endorphin / Q000097:blood*
chemical_list: D001615:beta-Endorphin