Acute and chronic effects of resistive exercise on blood pressure in hypertensive elderly women.

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.

The Effects of Strength Training Combined with Vitamin C and E Supplementation on Skeletal Muscle Mass and Strength: A Systematic Review and Meta-Analysis.

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.

Antioxidant Supplementation Impairs Changes in Body Composition Induced by Strength Training in Young Women.

Strength training (ST) is known to promote muscle hypertrophy and body composition adaptations. However, only a few studies investigated the effects of ST combined with antioxidant supplementation (AS) on these adaptations. The aim of this study was to investigate chronic effects of ST combined with AS on fat mass (FM) and fat-free mass (FFM) of young women. In a double-blinded design, thirty-three subjects (22.9 ± 2.5 years, 57.7 ± 8.4 kg, 1.6 ± 0.6 m) were allocated into three groups: 1) vitamins (n=12), 2) placebo (n=11) and 3) control (n=10). Vitamins and placebo underwent a ST program for 10 weeks. Vitamins supplemented with vitamin C (1g/day) and E (400IU/day) during the training period. FM and FFM were assessed by DEXA. Multiple 3 x 2 (group x time) mixed-factor ANOVA with Tukey adjustment was performed to examine differences in the dependent variables. The significance level was set at P ≤ .05. Only placebo increased total FFM (34.9 ± 4.9 vs 36.3 ± 4.8 kg, P<0.05) and decreased total FM (21.8 ± 7.8 vs 21.0 ± 8.3 kg, P<0.05) after training for 10 weeks. Moreover, only placebo presented a significantly greater FFM percent change from pre to post-intervention compared to control (4.0 ± 3.4 vs -0.7 ± 3.1%, respectively, P < 0.05). These results suggest that chronic AS can mitigate ST related improvements of body composition in young women.

Comparative Evaluation of Adiposity Indices as Predictors of Hypertension among Brazilian Adults.

PURPOSE: To compare several anthropometric indices in the prediction of hypertension among adults. METHODS: This is a cross-sectional study. Five hundred and eighteen adult men and women (40.9 ± 10.5 years; 1.62 ± .09 m; 72.3 ± 15.6 kg) volunteered to participate and underwent blood pressure and anthropometric measures. Anthropometric assessments were used to calculate body mass index (BMI), waist circumference (WC), waist-to-hip ratio (WHR), waist-to-stature ratio (WSR), body adiposity index (BAI), and conicity index (C). Comparisons between men and women were carried out by independent t-test and chi-square test. Cut-off points for each adiposity index to predict hypertension were obtained using Receiver Operating Characteristic (ROC) curve analyses. The significance level was set at P ≤ .05. RESULTS: All adiposity indices regarding both genders showed significant odds ratios, except BAI (odds ratio: 1.534; CI: 0.916-2.571) for women. In men, WHR and WSR were considered as more balanced indices regarding their sensitivity (AUC: 73.8 and 71.4, respectively) and specificity (AUC: 77.6 and 73.1, respectively). In women, WHR and WSR presented areas under the ROC curves higher than C index (P = .007) and BAI (P = .03), respectively. CONCLUSION: Indices that consider abdominal adiposity such as WC, WHR, and WSR have a stronger relationship with hypertension compared to others.

Effect of strength training combined with antioxidant supplementation on muscular performance.

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.

Comparison of adiposity indices and cut-off values in the prediction of metabolic syndrome in postmenopausal women.

AIMS: To compare adiposity indices and to assess their various cut-off values for the prediction of metabolic syndrome (MetS) in postmenopausal women. METHODS: One hundred forty nine volunteers (67.17±6.12 years) underwent body composition assessment using DXA and had 5 anthropometric indices measured (Waist Circumference, WC; Waist-to-Height Ratio, WHtR; Body Mass Index, BMI; Body Adiposity Index, BAI; and Conicity Index). Blood pressure was assessed using an oscillometric device and fasting blood samples were collected. MetS was classified according NCEP-ATP III. Cut-off values to predict MetS were obtained using Receiver Operating Characteristic (ROC) curve analyses and odds ratios were also calculated. RESULTS: MetS prevalence was 29.5% and subjects who were classified with MetS showed worse cardiometabolic outcomes and higher anthropometric indices values (p<0.05). With the exception of total- and LDL-cholesterol, all remaining variables were significantly correlated with at least one of the adiposity indices, with the strongest relationships observed for the indices reflecting central body fat. The cut-off values were 88cm, 0.57cm/cm, 26.85kg/m(2), 43.7%, 36.34%, and 1.24 units for WC, WHtR, BMI, DXA-derived body fat percentage, BAI, and conicity index, respectively. Significant greater risks for MetS were found for volunteers who had WHtR (odds=9.08; CI: 1.81-45.47) or WC (odds=5.20; CI: 1.30-20.73) measurements above cut-off values. CONCLUSION: Adiposity indices are associated with MetS in postmenopausal women in different degrees. Indices which consider central adiposity such as WC and WHtR have a stronger relationship with MetS compared to DXA-derived body fat percentage, which is considered a gold standard.