Post-exercise hypotension following different resistance exercise protocols

Sport Sciences for Health - To investigate the hemodynamic responses, especially HPE following different resistance exercises RE protocols in young adult subjects. Eighty-nine men...     

Does aerobic exercise intensity affect health‐related parameters in overweight women?

The aim of this study was to compare the effect of a cycling training programme performed at intensity corresponding to the lowest value of the respiratory quotient (RQ) versus at intensity corresponding to the ventilatory threshold (VT), on body composition and health‐related parameters in overweight women. Thirty‐two sedentary obese women (27–42 years old) were studied in a randomized trial of either RQ (n = 17) or VT (n = 15). RQ and VT training sessions were equalized by time (60 min) and performed in a cycloergometer. Anthropometry, body composition, lipid profile, glucose, basal metabolic rate (BMR) and fitness (maximal oxygen uptake) were evaluated before and after 12 weeks of intervention. Body weight, body mass index, fatness and fitness were improved in both groups (P<0·001). Triglycerides (TG) levels decreased only in response to RQ (P<0·001) and fat‐free mass (FFM) to VT (P = 0·002). No differences were observed between groups. Both exercise intensities seem to be effective for improving health in overweight women. However, low‐intensity compared with the high‐intensity exercise training appears to have additional benefits on TG levels and to maintenance of FFM.     

Reliability of Vertical Jump Performance evaluated with contact mat in elderly women

The aim of this study was to evaluate the reliability of the vertical jump (VJ) using a contact mat in elderly women. Thirty‐one physically active women aged 69·5 ± 5·6 years participated in this study. Jump performance was evaluated with a contact mat. The first testing session (s1) consisted of four countermovement jumps interspersed with 40 s rest intervals. After a period of 5–7 days, volunteers performed the second session (s2) utilizing the same procedures. The intersession statistical analysis was calculated considering the two highest jumps, one obtained in each section. The intra‐session analysis utilized all eight jumps, all four from each section, and the differences between means were calculated by repeated measures ANOVA. Reliability was tested using the intra‐class correlation coefficient (ICC) and agreement by the Bland–Altman method. The intra‐ and inter‐subject variation percentage was calculated by the coefficient of variation (CV). Results: The intersession results displayed a high ICC (0·91; P<0·001) and a good agreement verified by the Bland–Altman method. There was a significant difference in the intra‐session analysis only in s2 between the jumps 2 and 4. Both in s1 and s2, the ICC was high (0·96; P<0·001; 0·95; P<0·001), and the within session reliability CV was low (10·14% and 9·07%). Conclusion: In physically active elderly women, VJ evaluation using a contact mat is a reliable method and could be used to estimate jump height. Additionally, the results of this study could serve as reference values in similar samples evaluated with the same procedures.     

Understanding the individual responsiveness to resistance training periodization

This study was designed to compare the effects of linear periodization (LP) and undulating periodization (UP) on functional capacity, neuromuscular function, body composition, and cytokines in elderly sedentary women. We also aimed to identify the presence of high responders (HR), medium responders (MR), and low responders (LR) for irisin, interleukin-1 beta (IL-1β), toll-like receptor-4 (TLR-4), and brain-derived neurotrophic factor (BDNF) to resistance training (RT). Forty-nine elderly women were assigned to a control group, LP, and UP scheme. Functional capacity, body composition, maximal strength, irisin, TLR-4, BDNF, and IL-1β were evaluated. Both periodization models were effective in improving 45° leg press 1RM, chair-stand, arm curl, and time-up and go tests, with no significant differences in body composition and cytokines. Furthermore, HR, MR, and LR were identified for irisin, IL-1β, TLR-4, and BDNF, with differences between groups and moments. This study provides evidence that both periodization models were effective in improving functional capacity and neuromuscular function, with no effect on body composition and cytokines (probably as a consequence of the different responsiveness). Furthermore, for the first time, HR, MR, and LR were identified for irisin, IL1-β, TLR-4, and BDNF in response to RT.     

Moderate exercise increases the metabolism and immune function of lymphocytes in rats

Exercise modulates both glucose and glutamine metabolism which influences lymphocyte function. We investigated the influence of chronic moderate exercise on glucose and glutamine metabolism in lymphocytes, the associated influence on proliferation, and cytokine and immunoglobulin production. Male Wistar rats (8 weeks old) were placed in an exercise training group (N = 15, 1 h day^?1 at 60 % VO_2max, 5 days week^?1) for 8 weeks of exercise, or a sedentary control group. Twenty-four hours following the final training session, lymphocytes were separated, and the incorporation of [U-14C]-glucose, [U-14C]-glutamine, and [2-14C]-thymidine from the supernatant was measured. The activity of glucose-6-phosphate dehydrogenase, hexokinase, and glutaminase was measured. Lymphocytes were stimulated with ConA and LPS and incubated with the Mycobacterium bovis bacille Calmette-Guerin (BCG) vaccine and plasma IgG and IgE were measured. Glutamine metabolism increased in both T and B lymphocytes in the trained group. In the trained group, proliferative capacity increased T lymphocytes under ConA stimulation, and increased B lymphocytes with LPS. There was a significant increase in IL-2 production and decrease in IL-4 in the trained group compared with sedentary controls. IL-2R and TNFR increased in trained rats while IL-4R decreased and were more pronounced in T lymphocytes compared with B lymphocytes. In both lymphocyte subsets, exercise training significantly increased the expression of CD54+ and CD30+ cell markers. Exercise training increased plasma IgG compared with the sedentary group. In conclusion, moderate exercise training improves immune function and metabolism in T and B lymphocytes, reflecting an increased ability to respond to immune challenges.     

Acute effects of resistance training on cytokines and osteoprotegerin in women with metabolic syndrome

Chronic inflammation has been identified as an important component of metabolic syndrome (MetS). Inhibition of the inflammatory mediator signals is a promising strategy against insulin resistance, atherosclerosis and other problems associated with MetS. Regular exercise decreases the components associated with MetS, including inflammatory cytokines. However, the relationship between an acute resistance training (RT) session, cytokine levels and MetS is unclear. Therefore, the aim was to evaluate the effects of a single bout of acute RT on tumour necrosis factor (TNF‐α), interleukins (IL) IL‐1a, IL‐1β, IL‐12, IL‐6, IL‐10 and osteoprotegerin (OPG) in women with MetS. Twenty‐four women were divided into 2 groups: metabolic syndrome (MetS) and non‐metabolic syndrome (Non‐MetS). After the familiarization and testing for 1 repetition maximum (1RM), participants completed 3 sets of 10 repetitions in the following exercises: machine leg press, leg extension, leg curl, chest press, lat front pull‐down and machine shoulder press with 60% of 1RM followed by 15 repetitions of abdominal crunches. A rest interval of 1 min was allowed between sets and exercises. Plasma TNF‐α, IL‐1a, IL‐1β, IL‐12, IL‐6, IL‐10 and OPG were measured before, immediately post and 60 min after RT. MetS group showed significantly higher concentrations of IL‐1β (P = 0·024) and IL‐6 (P = 0·049) and a trend for higher TNF‐α values (P = 0·092) compared with Non‐MetS. There was no group × time interactions after the RT session on the measured cytokines and osteoprotegerin. In conclusion, acute RT session induced no additional increase in pro‐inflammatory cytokines nor a decrease in anti‐inflammatory cytokines and OPG in women with MetS.     

Influence of exercise order on upper body maximum and submaximal strength gains in trained men

The purpose of this study was to investigate the influence of exercise order on one‐repetition maximum (1‐RM) and ten‐repetition maximum (10‐RM) strength gains after 6 weeks of resistance training (RT) in trained men. Sixteen men were randomly assigned into two groups based on the order of exercises performed during training sessions: a group that performed large muscle group exercises first and progressed to small muscle group exercises (LG‐SM); while a second group performed the opposite sequence and started with small muscle group exercises and progressed to large muscle group exercises (SM‐LG). Four sessions of RT were conducted per week; all exercises were performed for three sets of 8–12 repetitions with 1‐min rest intervals between sets. Maximal and submaximal strength were assessed at baseline and after 6 weeks of RT with 1‐RM and 10‐RM testing for the bench press (BP), lat pulldown (LPD), triceps pulley extension (TE) and biceps curl (BC), respectively. Two‐way ANOVA for the 1‐RM and 10‐RM tests indicated a significant group x time interaction. The 1‐RM values significantly increased for all exercises in both groups (P<0.05), but were not significantly different between groups. However, effect size (ES) data indicated that the LG‐SM group exhibited a greater magnitude of gains (1‐RM and 10‐RM) for the BP and LPD exercises. Conversely, ES indicated that the SM‐LG group exhibited a greater magnitude of gains (1‐RM and 10‐RM) for the TE and BC exercises. In conclusion, the results suggest that upper body movements should be prioritized and performed according to individual needs to maximize maximal and submaximal strength.     

Matrix metallopeptidase 2 activity in tendon regions: effects of mechanical loading exercise associated to anabolic-androgenic steroids

Matrix metallopeptidases (MMPs) are responsible for degradation of the extracellular matrix components and tissue remodeling. To achieve a better understanding of AAS effects in rat tendon, MMP-2 activity in the proximal and distal regions of the calcanear tendon (CT) and proximal, intermediate and distal region of superficial (SFT) and deep flexor tendons (DFT) after mechanical load exercise associated with AAS was investigated. Animals were grouped into four groups: sedentary animals (S); sedentary animals with ASS supplementation (S + A); trained animals (T) and trained animals with AAS supplementation (T + A). Analysis of MMP activity in tendon extracts was done by gelatin zymography. Both proximal and distal regions of the calcanear tendon showed the lowest MMP-2 concentration and the highest proportion in MMP-2 active form. The intermediate region of the SFT differed (P < 0.01) from the proximal and distal regions with higher % of active MMP-2 in the sedentary group. The proportion of active MMP-2 decreased in the proximal region of the CT. AAS treatment strongly decreased both MMP-2 concentration and active form in the three regions of the SFT and on the proximal region of the CT, but not on the DFT. The differences in the response to exercise and AAS treatment are a result of distinct metabolism and recruitment of these tendon regions in the exercise program employed in this study.