title: Effects of low-volume resistive exercise on beta-endorphin and cortisol concentrations.
abstract: It has been recently suggested that high and sustained lactate levels may elicit increases in peripheral B-EN concentrations (16). We have observed elevated and sustained lactate concentrations in response to a low-volume resistive exercise protocol (14) that were similar to those from other exercise protocols that produced elevated beta-endorphin (B-EN) concentrations. Thus, the purpose of the study was to determine the effects of a low-volume (21,700 J) resistive exercise repetition maximum (RM) protocol using weight machines on peripheral lactate, B-EN and cortisol concentrations. Subjects completed 3 sets of bench press, lat-pull, leg extension, and leg curl exercise at a 10-RM load. Blood samples were collected and rating of perceived exertion (RPE, 15-point Borg scale) was assessed before exercise (-40 and -10 min), after each exercise, and after the exercise session (+ 35 min); blood samples were collected at 7 additional post-exercise times. RPE increased significantly throughout the exercise. Lactate concentrations rose significantly to peak at 8.54 mM at LE. B-EN and cortisol concentrations (-10) of 4.63 +/- 0.54 pmol.l-1 and 12.09 +/- 1.44 micrograms.dl-1, respectively, were not significantly elevated over time. The data suggest that a low-volume resistive exercise protocol using weight machines elevates lactate concentrations without altering B-EN and cortisol concentrations.
authors.affiliation: Department of Kinesiology and Health Studies, Southeastern Louisiana University, Hammond 70402, USA.
authors.forename: R R
authors.initials: RR
authors.lastname: Kraemer
authors.forename: E O
authors.initials: EO
authors.lastname: Acevedo
authors.forename: D
authors.initials: D
authors.lastname: Dzewaltowski
authors.forename: J L
authors.initials: JL
authors.lastname: Kilgore
authors.forename: G R
authors.initials: GR
authors.lastname: Kraemer
authors.forename: V D
authors.initials: VD
authors.lastname: Castracane
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006854:Hydrocortisone / Q000097:blood*; D008297:Male; D010953:Plasma Volume; D001615:beta-Endorphin / Q000097:blood*
chemical_list: D001615:beta-Endorphin; D006854:Hydrocortisone