Plasmaß‐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.

Participation of endogenous opioids in the antinociception induced by resistance exercise in rats

“…Many studies have demonstrated an increase in the plasma levels of endogenous opioids, mostly β-endorphin, during and after aerobic exercise (5); however, only a few studies have investigated alterations in this parameter when resistance exercise was involved, with equivocal results. Analysis of blood samples of athletes submitted to 3 sets of 8 repetitions at 80% of 1 RM showed no significant change in the circulating β-endorphin levels (14), while a significant increase in plasma β-endorphin levels was detected in men after a high total work-exercise protocol (15).…”

β-Endorphin Immunoreactive Material and Authentic β-Endorphin in the Plasma of Males Undergoing Anaerobic Exercise on a Rowing Ergometer

“…More detailed investigations revealed that an anaerobic state, which was reached at a threshold of about 90 % of maximum oxygen consumption and was documented by a blood lactate level of more than 4 mmol/l arterialized blood, leads to a considerable increase of β-endorphin levels in human plasma under exercise [24,26]. Compatible with these findings was the fact that non-exhaustive performance such as heavy resistance exercise, although requiring high muscular activity for short time periods, did not lead to an increase of β-endorphin levels at all [20], even decreased them [21], or only allowed an increase under approximately exhaustive conditions [14]. On the other hand, one would have expected an enhancement of exhaustive exercise-induced β-endorphin release under additional hypoxia which, however, was not observed [5,13].…”

Vernonia cinerea Less. supplementation and strenuous exercise reduce smoking rate: relation to oxidative stress status and beta-endorphin release in active smokers

“…It should be noted that in group 1, the slight reduction of β-end level was significant (p < 0.05), thus suggesting that the increased β-end in group 2 and 3 most likely resulted from exercise only and not from VC. From previous reports, the intensity and type of exercise for increasing β-end is still unclear, but resistance and moderate intensity exercise did not influence β-endorphin level [46]. …”