The purpose of this study was to investigate postexercise hypotension (PEH) during a 4-month period of resistance training in hypertensive elderly women. Sixty-four women were divided into 2 groups: an experimental group (EG), which performed resistance training, and a control group (CG) that did not practice any exercise. The EG carried out the following steps: (a) 3 weeks of exercise adaptation and 1 repetition maximum (1RM) test (month 1); (b) resistance exercise at 60% 1RM (month 2); (c) resistance exercise at 70% 1RM (month 3); (d) resistance exercise at 80% 1RM (month 4); and (e) PEH analyses at the end of each month. Measurements of systolic (SBP) and diastolic blood pressure (DBP) were calculated each 5 minutes during a 20-minute resting period before the sessions and each 15 minutes during 1 hour of post-session recovery. Analysis of covariance for repeated measures showed a reduction in SBP of about 14 mm Hg (p ≤ 0.05) and in DBP of 3.6 mm Hg (p ≤ 0.05) between resting values after the training period. In the EG group, SBP showed acute PEH during months 2 and 3, whereas DBP showed acute PEH during months 2 and 4. The CG did not show acute PEH or variations during the 4-month period. Postexercise hypotension occurrence and chronic reduction of resting blood pressure observed in the EG may have a protective effect on the cardiovascular system of the study participants.
16 September 2015 in Clinical Physiology and Functional Imaging
Objectives: The purpose of this study was to compare the effects of resistance training (RT) on body composition, muscle strength, and functional capacity in elderly women with and without sarcopenic obesity (SO). Methods: A total of 49 women (aged ≥60 years) were divided in two groups: without SO (non-SO, n=41) and with SO (n=8). Both groups performed a periodized RT program consisting of two weekly sessions for 16 weeks. All measures were assessed at baseline and postintervention, including anthropometry and body composition (dual-energy X-ray absorptiometry), muscle strength (one repetition maximum) for chest press and 45° leg press, and functional capacity (stand up, elbow flexion, timed “up and go”). Results: After the intervention, only the non-SO group presented significant reductions in percentage body fat (-2.2%; P=0.006), waist circumference (-2.7%; P=0.01), waist-to-hip ratio (-2.3; P=0.02), and neck circumference (-1.8%; P=0.03) as compared with baseline. Muscle strength in the chest press and biceps curl increased in non-SO only (12.9% and 11.3%, respectively), while 45° leg press strength increased in non-SO (50.3%) and SO (40.5%) as compared with baseline. Performance in the chair stand up and timed “up and go” improved in non-SO only (21.4% and -8.4%, respectively), whereas elbow flexion performance increased in non-SO (23.8%) and SO (21.4%). Effect sizes for motor tests were of higher magnitude in the non-SO group, and in general, considered “moderate” compared to “trivial” in the SO group. Conclusion: Results suggest that adaptations induced by 16 weeks of RT are attenuated in elderly woman with SO, compromising improvements in adiposity indices and gains in muscle strength and functional capacity.
1 August 2018 in Applied Physiology, Nutrition, and Metabolism
This was a placebo-controlled randomized study that aimed to investigate the effects of strength training (ST) combined with antioxidant supplementation on muscle performance and thickness. Forty-two women (age, 23.8 ± 2.7 years; body mass, 58.7 ± 11.0 kg; height, 1.63 ± 0.1 m) were allocated into 3 groups: vitamins (n = 15), placebo (n = 12), or control (n = 15). The vitamins and placebo groups underwent an ST program, twice a week, for 10 weeks. The vitamins group was supplemented with vitamins C (1 g/day) and E (400 IU/day) during the ST period. Before and after training, peak torque (PT) and total work (TW) were measured on an isokinetic dynamometer, and quadriceps muscle thickness (MT) was assessed by ultrasound. Mixed-factor ANOVA was used to analyze data and showed a significant group × time interaction for PT and TW. Both the vitamins (37.2 ± 5.4 to 40.3 ± 5.6 mm) and placebo (39.7 ± 5.2 to 42.5 ± 5.6 mm) groups increased MT after the intervention (P < 0.05) with no difference between them. The vitamins (146.0 ± 29.1 to 170.1 ± 30.3 N·m) and placebo (158.9 ± 22.4 to 182.7 ± 23.2 N·m) groups increased PT after training (P < 0.05) and PT was higher in the placebo compared with the control group (P = 0.01). The vitamins (2068.3 ± 401.2 to 2295.5 ± 426.8 J) and placebo (2165.1 ± 369.5 to 2480.8 ± 241.3 J) groups increased TW after training (P < 0.05) and TW was higher in the placebo compared with the control group (P = 0.01). Thus, chronic antioxidant supplementation may attenuate peak torque and total work improvement in young women after 10 weeks of ST.
1 July 2016 in Diabetes & Metabolic Syndrome: Clinical Research & Reviews
Intense muscle contractile activity can result in reactive oxygen species production in humans. Thus, supplementation of antioxidant vitamins has been used to prevent oxidative stress, enhance performance, and improve muscle mass. In this sense, randomized controlled studies on the effect of vitamin C and E supplementation combined with strength training (ST) on skeletal muscle mass and strength have been conducted. As these studies have come to ambiguous findings, a better understanding of this topic has yet to emerge. The purpose of the present review is to discuss the current knowledge about the effect of vitamin C and E supplementation on muscle mass and strength gains induced by ST. Search for articles was conducted in the following databases: PubMed/Medline, Web of Science, Scopus, Cochrane Central Register of Controlled Trials, and Google Scholar. This work is in line with the recommendations of the PRISMA statement. Eligible studies were placebo-controlled trials with a minimum of four weeks of ST combined with vitamin C and E supplementation. The quality of each included study was evaluated using the Physiotherapy Evidence Database Scale (PEDro). 134 studies were found to be potentially eligible, but only seven were selected to be included in the qualitative synthesis. A meta-analysis of muscle strength was conducted with 3 studies. Findings from these studies indicate that vitamins C and E has no effect on muscle force production after chronic ST. Most of the evidence suggests that this kind of supplementation does not potentiate muscle growth and could possibly attenuate hypertrophy over time.