Gluteus Medius and Tensor Fascia Latae muscle activation levels during multi-joint strengthening exercises

Aim: To compare the activation of GMed and TFL in four multi-joint exercises in strength training protocols and to verify if the level of muscle activation is indicated for strength gains in resistance training protocols. Methods: Eleven recreational lifters had normalized muscle activation of GMed and TFL assessed during ten maximal repetitions of four multi-joint exercises: (1) bilateral supine bridge (BiBRG); (2) bilateral supine bridge with hip abducted (BiBRG-AB); (3) unilateral supine bridge (UniBRG) and (4) single-leg squat (SLS). Results: A load of exercises was significantly greater for the BiBRG and BiBRG-AB compared to the UniBRG and SLS (p<0.001). We observed that GMed activation was significant greater compared to TFL among the four exercises (p=0.004) [BiBRG: Δ=26.2%; BiBRG-AB: Δ=27.3%; UniBRG: Δ=24.5% and SLS: Δ=18.8%]. Additionally, GMed activation was classified as moderate (<40%iMVC) and TFL activation was classified as low (<20%iMVC) in all exercises. Conclusion: Our results demonstrated that GMed is more active than TFL in all analyzed exercises. However, the level of activation observed for GMed was below that recommended to strength gain in resistance training programs.(AU)

Effects of concurrent training associated with N-acetylcysteine on bone density of spontaneously hypertensive rats

Abstract Aim: The present study aimed to analyze the effects of N-acetylcysteine supplementation associated with concurrent training on the bone mineral density of spontaneously hypertensive elderly rats. Methods: For the present study, 28 male spontaneously hypertensive rats, six months old, were distributed in the following groups: control (C, n=7); control + N-acetylcysteine (CNAC, n=7); concurrent training (T, n=7); and concurrent training+N-acetylcysteine (TNAC, n=7). The concurrent training was composed of aerobic training on a treadmill and resistance training in the same training session, three times a week. Animals of the NAC groups received a dose equivalent to 120 mg/kg/day orally for eight weeks. The animals in the trained groups underwent training for eight weeks. The animals were evaluated at the beginning and end of the experiment. After euthanasia, the tibias and femurs were submitted to bone densitometry analysis in an X-ray dual emission device. Results: Lower weight variation was observed in the trained animals and a reduction in pressure values in all groups, but without a statistical difference (p> 0.05). The animals in the T and TNAC groups presented a better performance in the physical tests (p <0.05). In relation to bone, the NAC groups demonstrated a decrease in femoral bone density when compared to groups C and T. Finally, all experimental groups demonstrated an increase in tibial bone density, but with no statistical difference (p>0.05). Conclusion: The animals in group T demonstrated better performance in the physical tests. In addition, the NAC caused a reduction in the bone mineral density of the femur.

Effects of combined training on total ghrelin and tumor necrosis factor-α in obese middle-aged men

Abstract AIMS The aim of the present study was to investigate the effects of combined training (CT) on total ghrelin and tumor necrosis factor-α (TNF-α) levels in obese middle-aged individuals. METHODS Twenty two obese middle-aged men (49.32 ± 5.74 years; Body mass index: 30.88 ± 1.64 kg/m²) were randomly assigned to a combined training group (CTG, n = 12) or a control group (CG, n = 10). The CT consisted of aerobic (50-85% of VO2peak) and resistance (6-10 RM) training performed three times per week, 60 min per session for 24 weeks. The anthropometric measurements, cardiorespiratory test (VO2peak), maximal strength assessment (1RM) and plasma concentrations of total ghrelin and TNF-α were determined before (Pre) and after 24 weeks (Post) of the experimental period. RESULTS Decreases were found in body fat percentage (Δ% -19.8) and waist circumference (Δ% -2.8) for CTG at the Post moment as compared to the Pre moment. In addition, the CTG demonstrated increases for VO2peak (Δ% 13.4) and for 1-RM of bench press (Δ% 78.1), leg press (Δ% 22.3) and arm curl (Δ% 19.3) at the Post moment as compared to the Pre moment. However, total ghrelin levels remained unchanged for CTG and CG after the experimental period, while TNF-α levels increased for CG (p ≤ 0.05). CONCLUSION the CT protocol performed was not effective in repairing total ghrelin levels and was not correlated with changes in the TNF-α; however, the exercise training was able to improve body composition and functional capabilities and contained the worsening of systemic inflammation associated to obesity.

ADRB2 Gln27Glu polymorphism influenced changes in leptin but not body composition or metabolic and other inflammatory parameters after twelve weeks of combined training in overweight adolescents

ABSTRACT Aim To compare the anthropometric, metabolic, and inflammatory parameters of overweight adolescents after 12-weeks of resistance and aerobic training (CT), taking into account the Gln27Glu polymorphism of the β2 adrenergic receptor (ADRB2) gene. Methods Forty-seven adolescents (15.05±1.07y) were assigned to one of four groups, according to the presence or absence of the Glu27 allele: CT (CarrierT n=11; NoncarrierT n=11) or control (CarrierC n=13; NoncarrierC n=12). Body composition, abdominal fat, maturation, fitness, metabolic and lipid profile, inflammatory markers were assessed. The CT consisted of six resistance exercises, followed by 30 min of walking/running at 50-80% VO2max, totaling 60 min/session, three times a week. A mixed-model factorial ANOVA was used to compare variables at baseline and after 12-weeks. Results TC was effective in reducing total fat mass (NoncarrierT ES=.45, CarrierT ES=.27) and subcutaneous abdominal fat (NoncarrierT ES=.48, CarrierT ES=.46) and increasing lean mass (NoncarrierT ES=.58, CarrierT ES=.60) and fitness. CarrierT group showed a reduction in leptin (ES=.49). Conclusion The responses of body composition and physical fitness to TC were not influenced by the presence of the Gln27Glu polymorphism. However, only the Glu27 allele carriers showed reductions in leptin after 12-weeks. Besides, a lack of intervention caused obesogenic effects, especially in Glu27carriers.