Effect Of Concurrent Training With Blood Flow Restriction In The Elderly.

The aim of this present study was to investigate on the effects of concurrent training with blood flow restriction (BFR-CT) and concurrent training (CT) on the aerobic fitness, muscle mass and muscle strength in a cohort of older individuals. 25 healthy older adults (64.7±4.1 years; 69.33±10.8 kg; 1.6±0.1 m) were randomly assigned to experimental groups: CT (n=8, endurance training (ET), 2 days/week for 30-40 min, 50-80% VO2peak and RT, 2 days/week, leg press with 4 sets of 10 reps at 70-80% of 1-RM with 60 s rest), BFR-CT (n=10, ET, similar to CT, but resistance training with blood flow restriction: 2 days/week, leg press with 1 set of 30 and 3 sets of 15 reps at 20-30% 1-RM with 60 s rest) or control group (n=7). Quadriceps cross-sectional area (CSAq), 1-RM and VO2peak were assessed pre- and post-examination (12 wk). The CT and BFR-CT showed similar increases in CSAq post-test (7.3%, P<0.001; 7.6%, P<0.0001, respectively), 1-RM (38.1%, P<0.001; 35.4%, P=0.001, respectively) and VO2peak (9.5%, P=0.04; 10.3%, P=0.02, respectively). The BFR-CT promotes similar neuromuscular and cardiorespiratory adaptations as CT

Acute changes in serum and skeletal muscle steroids in resistance-trained men

IntroductionResistance exercise can significantly increase serum steroid concentrations after an exercise bout. Steroid hormones are involved in the regulation of several important bodily functions (e.g., muscle growth) through both systemic delivery and local production. Thus, we aimed to determine whether resistance exercise-induced increases in serum steroid hormone concentrations are accompanied by enhanced skeletal muscle steroid concentrations, or whether muscle contractions per se induced by resistance exercise can increase intramuscular steroid concentrations.MethodsA counterbalanced, within-subject, crossover design was applied. Six resistance-trained men (26 ± 5 years; 79 ± 8 kg; 179 ± 10 cm) performed a single-arm lateral raise exercise (10 sets of 8 to 12 RM - 3 min rest between sets) targeting the deltoid muscle followed by either squat exercise (10 sets of 8 to 12 RM - 1 min rest) to induce a hormonal response (high hormone [HH] condition) or rest (low hormone [LH] condition). Blood samples were obtained pre-exercise and 15 min and 30 min post-exercise; muscle specimens were harvested pre-exercise and 45 min post-exercise. Immunoassays were used to measure serum and muscle steroids (total and free testosterone, dehydroepiandrosterone sulfate, dihydrotestosterone, and cortisol; free testosterone measured only in serum and dehydroepiandrosterone only in muscle) at these time points.ResultsIn the serum, only cortisol significantly increased after the HH protocol. There were no significant changes in muscle steroid concentrations after the protocols.DiscussionOur study provides evidence that serum steroid concentration increases (cortisol only) seem not to be aligned with muscle steroid concentrations. The lack of change in muscle steroid after protocols suggests that resistance-trained individuals were desensitized to the exercise stimuli. It is also possible that the single postexercise timepoint investigated in this study might be too early or too late to observe changes. Thus, additional timepoints should be examined to determine if RE can indeed change muscle steroid concentrations either by skeletal muscle uptake of these hormones or the intramuscular steroidogenesis process

Comparison in responses to maximal eccentric exercise between elbow flexors. and knee extensors of older adults

To compare the susceptibility of elbow flexors (EF) and knee extensors (KE) to eccentric exercise-induced muscle damage in older individuals, since ageing could modulate the difference in the susceptibility to muscle damage between muscles. Cross-sectional and cross-over study design. Eight older (61.6 +/- 1.8 years) adults performed 5 sets of 6 maximal isokinetic (90 degrees s(-1)) eccentric contractions of the EF (range of motion: 80-20 degrees) and RE (30-90 degrees) with the non-dominant limb in a randomised, counterbalanced order with 2 weeks between bouts. Maximal voluntary isometric (MVC-ISO) and concentric contraction torque, optimum angle, range of motion (ROM), muscle soreness and serum creatine kinase (CM) activity were measured before, immediately after (except CM), and 24, 48, 72 and 96 h following exercise. Normalised changes in the variables following exercise were compared between EF and KE by a mixed model analysis of variance. Only MVC-ISO and ROM demonstrated significant group effects (p 0.05) were found between EF and KE for any of the dependent variables changes. These results suggest that the KE of older adults are relatively as susceptible to muscle damage as their EF, or at the very least, the difference between EF and KE are small for older adults. (C) 2013 Sports Medicine Australia1719195COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFund for the Support of Education, Research and Extension from the State University of Campinas (FAEPEX

Inflammatory responses after different velocities of eccentric exercise

The present study aimed to verify the indirect markers of muscle damage and inflammatory response following different velocities of eccentric exercise in women. Nine women performed isokinetic eccentric actions at a slow velocity (Ecc30 group, 23.8 +/- 2.0 years; 57.8 +/- 7.0 Kg; 1.6 +/- 0.5 m) and another ten women performed at high velocity (Ecc210 group, 22.2 +/- 3.9 years; 56.4 +/- 6.0 Kg; 1.6 +/- 0.5 m). Maximal voluntary isometric contraction (MVIC), range of motion (ROM), upper-arm circumference, muscle soreness, creatine kinase (CK), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6) and interleukin-10 (IL-10) were measured before, immediately after (except CK and cytokines), and 24, 48 and 72 h following exercise. Normalized changes in the variables following exercise were compared between velocities by a mixed model. The Ecc30 demonstrated greater CK activity than the Ecc210 (group vs. time interaction, P < 0.001). A group effect for circumference and ROM (P < 0.001) and a time effect for circumference (P = 0.003), ROM (P = 0.004), soreness (P < 0.001), TNF-alpha (P = 0.004), IL-6 (P = 0.001) and IL-10 (P = 0.041) were found. The Ecc30 showed large effect sizes for TNF-alpha and IL-6 compared to Ecc210, which presented small and moderate effect sizes, respectively. IL-10 showed a moderate effect size for both groups. The velocity of the eccentric exercise does not modulate the systemic anti-inflammatory response, at least for a low number of muscle contractions performed by a small muscle group in women2217784CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPsem informação2012/09709-0extracurricular project of weight training and fitness (Faculty of Physical Education of State University of Campinas - UNICAMP

Resistance training-induced changes in integrated myofibrillar protein synthesis are related to hypertrophy only after attenuation of muscle damage

Key points Skeletal muscle hypertrophy is one of the main outcomes from resistance training (RT), but how it is modulated throughout training is still unknown. We show that changes in myofibrillar protein synthesis (MyoPS) after an initial resistance exercise (RE) bout in the first week of RT (T1) were greater than those seen post-RE at the third (T2) and tenth week (T3) of RT, with values being similar at T2 and T3. Muscle damage (Z-band streaming) was the highest during post-RE recovery at T1, lower at T2 and minimal at T3. When muscle damage was the highest, so was the integrated MyoPS (at T1), but neither were related to hypertrophy; however, integrated MyoPS at T2 and T3 were correlated with hypertrophy. We conclude that muscle hypertrophy is the result of accumulated intermittent increases in MyoPS mainly after a progressive attenuation of muscle damage. AbstractSkeletal muscle hypertrophy is one of the main outcomes of resistance training (RT), but how hypertrophy is modulated and the mechanisms regulating it are still unknown. To investigate how muscle hypertrophy is modulated through RT, we measured day-to-day integrated myofibrillar protein synthesis (MyoPS) using deuterium oxide and assessed muscle damage at the beginning (T1), at 3weeks (T2) and at 10weeks of RT (T3). Ten young men (27(1)years, mean (SEM)) had muscle biopsies (vastus lateralis) taken to measure integrated MyoPS and muscle damage (Z-band streaming and indirect parameters) before, and 24h and 48h post resistance exercise (post-RE) at T1, T2 and T3. Fibre cross-sectional area (fCSA) was evaluated using biopsies at T1, T2 and T3. Increases in fCSA were observed only at T3 (P=0.017). Changes in MyoPS post-RE at T1, T2 and T3 were greater at T1 (