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.

Concurrent Validation of the OMNI Perceived Exertion Scale for Resistance Exercise

“…As such, Wt tot increased with accumulating repetitions within each set and also varied across the three successive sets for a given exercise. A volume loading protocol at 65% 1-RM intensity was used because it has been shown to produce: (a) a wide range of Wt tot within and between exercise sets for both upper-and lower-body resistance exercises (2,13,17,27), and (b) large increases in blood [Hla] above resting levels during isotonic resistance exercise (1,7,8,13,17,27). Large response ranges for both Wt tot and [Hla] were requisite for correlational analyses of the type used to establish concurrent scale validity.…”

“…R atings of perceived exertion (RPE) have been assessed for female and male subjects performing concentric and eccentric resistance exercise paradigms that varied the total volume of weight lifted (i.e., volume loading), percent of one repetition maximum muscular action (% 1-RM; i.e., intensity loading), and rest periods between separate sets and exercises (1,6 -8,14,17-19,26,27). These resistance exercise paradigms: (a) established force-effort psychophysical functions using torque, electromyography (EMG), and magnetic resonance imaging (MRI) as criterion measures (5,10,19,21); (b) examined blood lactic acid concentration ([Hla]), HR, EMG, epinephrine, norepinephrine, cortisol, betaendorphins, and pain as possible physiological mediators of the effort sense (1,4,7,8,11,13,(17)(18)(19)27,28); and (c) used RPE to prescribe muscular strength, endurance and hypertrophic training programs, and to track conditioning progress (1)(2)(3)9). In these foregoing investigations, RPE was assessed using the original and modified versions of Borg's 15-category scale and Borg's Category-Ratio (CR-10) scale.…”

“…For modes such as cycling and walking, the intensity of the various differenti-ated perceptual signals usually differs from that of the undifferentiated signal at a given time point during submaximal exercise (23). Some investigations involving resistance exercise have measured only the overall RPE (1,7,8,10,17,27,29) with perceptual estimates primarily recorded during the postexercise recovery period (2,29). However, a number of other investigations have differentiated RPE to active muscles during resistance exercise (2-5,11,12,18,20 -22), providing anatomic specificity to the perceptual response.…”

Effects of Exercise Intensity on Rating of Perceived Exertion During a Multiple-Set Resistance Exercise Session

“…However, the RPE during a multiple-set resistance exercise protocol has been poorly described. The few studies addressing this issue reported increases in RPE assets increased from moderate to high intensity (e.g., 80% of 10 repetition maximum [10RM], and 65% of 1RM) (12,13,22). In practice, these results suggest that a reduction in the intensity between sets is necessary to maintain the same RPE during multiple-set resistance training.…”

Níveis de beta-endorfina em resposta ao exercício e no sobretreinamento

“…Em contraste, esses mesmos autores depois verificaram que os níveis de -end 1-31 diminuíam significativamente após a realização de um protocolo similar de exercício de força aplicado em estudantes (63). Outro estudo, em que sete homens treinados executaram um protocolo de três séries de 10 RM com quatro exercícios diferentes, demonstrou que um baixo volume de exercício de força não aumenta significativamente os níveis de -end (62). Por outro lado, Kraemer e cols.…”