The findings suggest that non-invasive brain stimulation over the TC modulates the ANS activity and the sensory perception of effort and exercise performance, indicating that the brain plays a crucial role in the exercise performance regulation.
BackgroundThe loss of skeletal muscle mass (MM) or muscle function (MF) alone increases the risk for losing physical independence in older adults. We aimed to examine the independent and synergic associations of low MM and low MF, both criteria of sarcopenia, with the risk for losing projected physical independence in later life (+90 years old).MethodsCross‐sectional analyses were conducted in 3493 non‐institutionalized older adults (1166 males). Physical independence was assessed with a 12‐item composite physical function scale. Logistic regression was used to estimate the odds‐ratio (OR) for being at risk for losing physical independence.ResultsApproximately 30% of the participants were at risk for losing physical independence at 90 years of age. Independent analysis demonstrated that participants with low MM had 1.65 (95%CI: 1.27–2.31) increased odds for being at risk for losing physical independence and participants with low MF had 6.19 (95%CI 5.08–7.53) increased odds for being at risk. Jointly, having a low MM and a low MF increased the risk for losing physical independence to 12.28 (95%CI 7.95 to 18.96).ConclusionsAlthough low MM represents a risk factor for losing physical independence, low MF seems to play a more dominant role in this relationship, with the presence of both sarcopenia criteria representing a substantial risk for losing physical independence in later life.
Aging is associated with sarcopenia and dynapenia, with both processes contributing to functional dependence and mortality in older adults. Resistance training (RT) and increased protein intake are strategies that may contribute to health improvements in older adults. Therefore, the aim was to investigate the effects of whey protein (WP) supplementation consumed either immediately pre- or post-RT on skeletal muscle mass (SMM), muscular strength, and functional capacity in pre-conditioned older women. Seventy older women participated in this investigation and were randomly assigned to one of three groups: whey protein pre-RT and placebo post-RT (WP-PLA, n = 24), placebo pre-RT and whey protein post-RT (PLA-WP, n = 23), and placebo pre- and post-RT (PLA-PLA, n = 23). Each group ingested 35 g of WP or PLA. The RT program was carried out over 12 weeks (three times per week; 3 × 8–12 repetition maximum). Body composition, muscular strength, functional capacity, and dietary intake were assessed pre- and post-intervention. Two-way analysis of covariance (ANCOVA) for repeated measures, with baseline scores as covariates were used for data analysis. A time vs. group interaction (p < 0.05) was observed with WP-PLA and PLA-WP presenting greater increases compared with PLA-PLA for SMM (WP-PLA = 3.4%; PLA-WP = 4.2%; PLA-PLA = 2.0%), strength (WP-PLA = 8.1%; PLA-WP = 8.3%; PLA-PLA = 7.0%), and the 10-m walk test (WP-PLA = −10.8%; PLA-WP = −11.8%; PLA-PLA = −4.3%). Whey protein supplementation was effective in promoting increases in SMM, muscular strength, and functional capacity in pre-conditioned older women, regardless of supplementation timing. This trial was registered at ClinicalTrials.gov: NCT03247192.
The 1-repetition maximum test (1RM) has been widely used to assess maximal strength. However, to improve accuracy in assessing maximal strength, several sessions of the 1RM test are recommended. The aim of this study was to analyze the influence of previous resistance training experience on the reliability of 1RM test. Thirty men were assigned to the following 2 groups according to their previous resistance training experience: no previous resistance training experience (NOEXP) and more than 24 months of resistance training experience (EXP). All subjects performed the 1RM tests in bench press and squat in 4 sessions on distinct days. There was a significant session × group effect in bench press (F = 3.09; p < 0.03) and squat (F = 2.76; p < 0.05) showing that only the NOEXP increased maximal strength between the sessions. Significant increases (p < 0.05) in maximal strength occurred in the NOEXP between session 1 and the other sessions in bench press (session 1 vs. 2 = +3.8%; session 1 vs. 3 = +7.4%; session 1 vs. 4 = +10.1%), and squat (session 1 vs. 2 = +7.6%; session 1 vs. 3 = +10.1%; session 1 vs. 4 = +11.2%). Moreover, in bench press, maximal strength in sessions 3 and 4 were significantly higher than in session 2. The results of the present study suggest that the reliability of the 1RM test is influenced by the subject's previous experience in resistance training. Subjects without experience in resistance training require more practice and familiarization and show greater increases in maximal strength between sessions than subjects with previous experience in resistance training.
To investigate whether the manipulation of brain excitability by transcranial direct current stimulation (tDCS) modulates the heart rate variability (HRV), the effect of tDCS applied at rest on the left temporal lobe in athletes (AG) and non-athletes (NAG) was evaluated. The HRV parameters (natural logarithms of LF, HF, and LF/HF) was assessed in 20 healthy men before, and immediately after tDCS and sham stimulation. After anodal tDCS in AG the parasympathetic activity (HF(log)) increased (P<0.01) and the sympathetic activity (LF(log)) and sympatho-vagal balance (LF/HF(log)) decreased (P<0.01), whereas no significant effects were detected in NAG (P>0.05). No significant changes in HRV indexes were provoked by sham stimulation in both AG and NAG (P>0.05). In conclusion, tDCS applied on the left temporal lobe significantly increased the overall HRV in AG, enhancing the parasympathetic and decreasing the sympathetic modulation of heart rate. Consequently the sympatho-vagal balance decreased at rest in AG but not in NAG. Releasing a weak electric current to stimulate selected brain areas may induce favorable effects on the autonomic control to the heart in highly fit subjects.
The aim of this study was to analyze the effects of resistance training (RT) performed with 1 or 3 sets per exercise on osteosarcopenic obesity (OSO) syndrome parameters in older women. Sixty-two older women (68.0 ± 4.3 years, 26.8 ± 4.4 kg/m) participated in a 12-week RT program. Participants were randomly assigned into one of the three groups: two training groups that performed either 1 set (G1S, n = 21) or 3 sets (G3S, n = 20) 3 times weekly, or a control group (CG, n = 21). Body composition was assessed by dual X-ray absorptiometry, strength was evaluated by 1 repetition maximum testing. The G3S presented significantly higher strength changes than G1S. The changes for percentage of body fat were higher for G3S compared to G1S. There was no difference in skeletal muscle mass between G3S and G1S, however both training groups displayed greater increases in this outcome compared to CG. There was no effect for bone mineral density. The overall analysis indicated higher (P < 0.05) positive changes for G3S than G1S (composed Z-score: G3S = 0.62 ± 0.40; G1S = 0.11 ± 0.48). The results suggest that a 12-week RT period is effective to improve the risk factors of OSO, and that 3 sets induce higher improvements than a single set.
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