This study compared four different intensities of a bench press exercise for muscle soreness, creatine kinase activity, interleukin (IL)-1beta, IL-6, tumor necrosis factor-alpha (TNF-alpha), and prostaglandin E(2) (PGE(2)) concentrations in the blood. Thirty-five male Brazilian Army soldiers were randomly assigned to one of five groups: 50% one-repetition maximum (1-RM), 75% 1-RM, 90% 1-RM, 110% 1-RM, and a control group that did not perform the exercise. The total volume (sets x repetitions x load) of the exercise was matched among the exercise groups. Muscle soreness and plasma creatine kinase activity increased markedly (P < 0.05) after exercise, with no significant differences among the groups. Serum PGE(2) concentration also increased markedly (P < 0.05) after exercise, with a significantly (P < 0.05) greater increase in the 110% 1-RM group compared with the other groups. A weak but significant (P < 0.05) correlation was found between peak muscle soreness and peak PGE(2) concentration, but no significant correlation was evident between peak muscle soreness and peak creatine kinase activity, or peak creatine kinase activity and peak PGE(2) concentration. All groups showed no changes in IL-1beta, IL-6 or TNF-alpha. Our results suggest that the intensity of bench press exercise does not affect the magnitude of muscle soreness and blood markers of muscle damage and inflammation.
BackgroundThe effects of chronic aerobic exercise upon lipid profile has been previously demonstrated, but few studies showed this effect under resistance exercise conditions.ObjectiveThe aim of this study was to examine the effects of different resistance exercise loads on blood lipids.MethodsThirty healthy, untrained male volunteers were allocated randomly into four groups based at different percentages of one repetition maximum (1 RM); 50%-1 RM, 75%-1 RM, 90%-1 RM, and 110%-1 RM. The total volume (sets × reps × load) of the exercise was equalized. The lipid profile (Triglycerides [TG], HDL-cholesterol [HDL-c], LDL-cholesterol, and Total cholesterol) was determined at rest and after 1, 24, 48 and 72 h of resistance exercise.ResultsThe 75%-1 RM group demonstrated greater TG reduction when compared to other groups (p < 0.05). Additionally, the 110%-1 RM group presented an increased TG concentration when compared to 50% and 75% groups (p = 0.01, p = 0.01, respectively). HDL-c concentration was significantly greater after resistance exercise in 50%-1 RM and 75%-1 RM when compared to 110%-1 RM group (p = 0.004 and p = 0.03, respectively). Accordingly, the 50%-1 RM group had greater HDL-c concentration than 110%-1 RM group after 48 h (p = 0.05) and 72 h (p = 0.004), respectively. Finally, The 50% group has showed lesser LDL-c concentration than 110% group after 24 h (p = 0.007). No significant difference was found in Total Cholesterol concentrations.ConclusionThese results indicate that the acute resistance exercise may induce changes in lipid profile in a specific-intensity manner. Overall, low and moderate exercise intensities appear to be promoting more benefits on lipid profile than high intensity. Long term studies should confirm these findings.
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