It may be that resistance exercise can be used to prevent the degenerative processes and inflammation associated with ageing. Thus, the aim of the present study was to evaluate the effects of resistance training on cytokines, leptin, resistin, and muscle strength in post-menopausal women. Thirty-five sedentary women (mean age 63.18 years, s = 4.8; height 1.64 m, s = 0.07; body mass 57.84 kg, s = 7.70) were recruited. The 16 weeks of periodized resistance training consisted of two weekly sessions of three sets of 6-14 repetition maximum. Maximal strength was tested in bench press, 45 degrees leg press, and arm curl. Plasma tumour necrosis factor-alpha, interleukin-6, interleukin-15, leptin, and resistin were determined by enzyme-linked immunosorbent assay. Maximal strength on all measures was increased after 16 weeks. There were minor or no modifications in tumour necrosis factor-alpha and interleukin-15. Interleukin-6 was decreased 48 h after compared with baseline and declined after 16 weeks. Leptin decreased 24 h after compared with baseline and was reduced at baseline and 48 h after compared with pre-training. There was a decrease in resistin after 24 and 48 h compared with baseline and a decline in baseline and immediately after levels compared with pre-training. A possible explanation of the results of the present study is a lower production of pro-inflammatory cytokines by the innate immune system. Periodized resistance training seems to be an important intervention to reduce systemic inflammation in this population.

The aim of the present study was to investigate the effects of resistance training on skeletal muscle lipid content, liver lipid content, heart lipid content, fat depots, and lipid profile in ovariectomized rats. Wistar adult female rats were divided into 4 groups (n = 10 per group): sedentary (Sed-Intact), sedentary ovariectomized (Sed-Ovx), strength trained (ChronicEx-intact), and strength trained ovariectomized (ChronicEx-Ovx). A 12-week strength-training period was used, during which the animals climbed a 1.1-m vertical ladder with weights attached to their tails. The sessions were performed once every 3 days, with 4-9 climbs and 8-12 dynamic movements per climb. Ovariectomy increased liver lipid content and fat depots, and heart and muscle lipid content. There was an increase in the atherogenic index and a negative change in lipid profile because of the ovariectomy. Resistance training decreased lipid content in the liver, soleus, and tibialis anterior, decreased fat depots (mesenteric and retroperitoneal), and changed the lipid profile, independently of ovarian hormone status. These results indicate the potential benefits of resistance training as an alternative strategy to control the effects of ovariectomy on fat depot, lipid profile, and tissue lipid content.

The aims were both to determine lactate and ventilatory threshold during incremental resistance training and to analyze the acute cardiorespiratory and metabolic responses during constant-load resistance exercise at lactate threshold (LT) intensity. Ten healthy men performed 2 protocols on leg press machine. The incremental test was performed to determine the lactate and ventilatory thresholds through an algorithmic adjustment method. After 48 h, a constant-load exercise at LT intensity was executed. The intensity of LT and ventilatory threshold was 27.1±3.7 and 30.3±7.9% of 1RM, respectively (P=0.142). During the constant-load resistance exercise, no significant variation was observed between set 9 and set 15 for blood lactate concentration (3.3±0.9 and 4.1±1.4  mmol x L(-1), respectively. P=0.166) and BORG scale (11.5±2.9 and 13.0±3.5, respectively, P=0.783). No significant variation was observed between set 6 and set 15 for minute ventilation (19.4±4.9 and 22.4±5.5 L x min(-1), respectively, P=0.091) and between S3 and S15 for VO2 (0.77±0.18 and 0.83±0.16 L x min(-1), respectively, P=1.0). Constant-load resistance exercise at LT intensity corresponds to a steady state of ventilatory, cardio-metabolic parameters and ratings of perceived exertion.

Resistance incremental tests (IT) make it possible to determine critical metabolic and cardiovascular changes, such as the lactate threshold (LT). Different methods are frequently used to improve the exactness of LT identification. The objective of the study was to identify LT by four different methods (visual inspection, log-log, algorithmic adjustment and QLac) during resistance exercise and to evaluate which methods present more precision. Twelve men performed a maximal IT on the leg press at relative intensities of 10%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80% and 90% of 1RM with 1-min stages. During the 2-min interval between stages, capillary blood was collected for blood lactate analysis. LT was detected using each of the four methods. The intensity of LT by visual inspection method was 26·9 (5·2)% of 1RM, adjustment algorithmic method was 27·8 (3·6)% of 1RM, log-log method was 23·3 (3·5)% of 1RM and QLac method was 31·6 (9·8)% of 1RM, with significant difference only between log-log and QLac methods. Bland and Altman analysis shows better concordance for visual inspection versus adjustment algorithmic methods. The visual inspection, algorithmic and log-log methods detected the LT at the same intensity. The mathematical models, specially the algorithmic method, provide more precision.

IntroductionNon-invasive ventilation may improve autonomic modulation and ventilatory parameters in severely disabled patients. The aim of the present study was to evaluate the physiological influence of acute treatment with different levels of continuous positive airway pressure (CPAP) on the autonomic balance of heart and respiratory responses in patients with stable chronic obstructive pulmonary disease (COPD) and chronic heart failure (CHF).Materials and methodsA COPD group (n = 10), CHF group (n = 8) and healthy subjects (n = 10) were evaluated. The participants were randomized to receive three different levels of CPAP on the same day: sham ventilation (Sham), 5 cmH20 (CPAP5) and 10 cmH20 (CPAP10) for 10 min. Respiratory rate, end tidal carbon dioxide (ETCO2), peripheral oxygen saturation (SpO2), heart rate (HR), blood pressure and heart rate variability in the time and frequency domains were measured during spontaneous breathing and under the sham, CPAP5 and CPAP10 conditions.ResultsAll groups experienced a reduction in ETCO2 values during treatment with CPAP (p < 0.05). CPAP increased SpO2 and HR in the COPD group (p < 0.05). The COPD group also had lower RMSSD values during treatment with different levels of CPAP when compared to the control group (p < 0.05). In the CHF group, CPAP5 and CPAP10 increased the SDNN value (p < 0.05). CPAP10 reduced the SDNN value in the COPD group (p < 0.05).ConclusionThe findings suggest that CPAP may cause improvements in the neural control of heart rate in patients with stable COPD and CHF. For each patient, the “best CPAP level” should be defined as the best respiratory response and autonomic balance.

The purpose of this study was to investigate the influence of resistance training on the activity of matrix metalloproteinase (MMP)-2 and bone biomechanical properties in ovariectomized and intact rats. Forty-eight female rats were divided into two distinct groups, ovariectomized (OVX) and intact (Int), which were subdivided into three similar subgroups: sedentary, acute exercise and chronic exercise. Rats performed a resistance training for 12 weeks in which animals climbed a vertical ladder of 1.1 m with weights attached to their tails. Sessions were performed with an interval of 3, 4-9 and 8-12 days scaled dynamic movements of climbing. Biomechanical and physical analyses were performed using a universal testing machine, and MMP-2 activity analysis by zymography. Bone density (BD), mineral density (MD), maximum load and fracture load was reduced in sedentary and acute exercise OVX groups compared with the sedentary intact group (P<0.05); in contrast, chronically trained groups (OVX and Int) showed a significant increase in BD, MD and fracture load compared with all the other groups. MMP-2 activity in chronically trained groups also showed a significant increase, while the sedentary OVX group showed a decrease in MMP-2 activity compared with the intact sedentary group (P<0.05). Our results suggest that the resistance training proposed in our work was efficient in reverting the deleterious effects of ovariectomy on bone tissue, and also produced modeling effects in intact rats. On the other hand, ovariectomy reduced the activity of MMP-2 and produced deleterious effects on bone tissue, mimicking menopause intrinsically.

The purpose of the present study was to correlate the acute and chronic decrease in blood pressure (BP) following resistance training (RT). 13 normotensive women (18-49 years) completed an acute whole body RT session with 3 sets of 10 repetitions at 60% 1RM and then 8 weeks of RT as follows: 3/week, 3 sets of 8-12 repetitions maximum. Systolic (SBP) and diastolic BP (DBP) were measured up to 60 min and 24 h following RT (acute and chronic). The greatest acute decrease of SBP (108.5±7.0 mmHg) and DBP (71.5±6.4 mmHg) values over the 60-min period were reduced compared to pre-exercise (117.3±11.7 and 79.3±8.2 mmHg, respectively; p<0.05). The chronic effect on resting BP was observed only for those presenting acute post-exercise hypotension (PEH). The change in both SBP and DBP following acute RT was correlated with the chronic change in resting SBP and DBP (r>0.5; p≤0.05). The change in 24 h BP after acute RT was correlated with the chronic reduction in SBP (r=0.74) and DBP (r=0.80). The magnitude of PEH is a promising candidate for the prediction of individual BP-related training efficacy.

This investigation was designed to evaluate responses of blood pressure (BP) following an acute resistance exercise (RE) session. Middle-aged women (N=13) who were classified as overweight (N=8) or obese (N=5) according to body mass index (BMI) participated in the investigation. Participants were randomly submitted to a control session (30-min seated rest) and a exercise session (3 sets, 10 repetitions at 60% 1RM of exercises for the upper and lower body) with systolic (SBP), diastolic (DBP) and mean blood pressure (MBP) obtained at rest and 10, 20, 30, 40, 50, and 60-min following exercise, and through 24 h. Acute RE decreased SBP at 10, 30, and 40-min compared with pre-exercise and control (P<0.05). DBP decreased at 10 and 40-min post-exercise compared with the control trial (P<0.05). Both SBP and DBP decreased in the nighttime period (-4.2 mmHg and -4.1 mmHg, respectively) and in the overall 24 h period (-3.6 mmHg and -4.5 mmHg, respectively) following the acute RE session when compared with the control trial. These findings indicate important benefits of acute RE on BP circadian rhythm, particularly at night as well as in the morning, which are critical periods associated with increased risk for cardiovascular events.