PurposeTo examine the effects of resistance training (RT) on metabolic syndrome-related phenotypes in postmenopausal women.Patients and methodsTwenty-two postmenopausal women (65.0±4.2 years) underwent 12 weeks of whole body progressive training with intensity prescribed based on rating of perceived exertion. Dominant knee extension strength was assessed using an isokinetic dynamometer before and after the intervention. Moreover, all volunteers had blood samples collected for lipid profile, glycemic control, and C-reactive protein analyses. Waist circumference and arterial blood pressure were also measured at baseline and after the training period. Student’s t-tests for paired samples and repeated measures ANOVA were used to compare dependent variables, and statistical significance was set at P<0.05.ResultsIsokinetic muscle strength significantly increased (P<0.01) with training. It was observed that waist circumference as well as total and low-density lipoprotein cholesterol levels significantly decreased with training (P<0.01). Total cholesterol/high-density lipoprotein cholesterol ratio, an important marker of cardiovascular disease incidence, was also significantly reduced (from 3.91±0.91 to 3.60±0.74; P<0.01) after the program. Blood glucose, basal insulin, and homeostatic model assessment of insulin resistance were also significantly reduced (P<0.01). No significant alterations were observed for resting blood pressure, triglycerides, or C-reactive protein.ConclusionBased on the observed results, it can be concluded that a 12-week progressive RT program, besides increasing isokinetic muscle strength, induces beneficial alterations on metabolic syndrome-related phenotypes in postmenopausal women. These findings highlight this mode of exercise as an important component of public health promotion programs for aged women. RT improves isokinetic strength and metabolic syndrome-related phenotypes in postmenopausal women.

No abstract

Context: Neuromuscular electrical stimulation is widely used to induce muscular strength increase; however, no study has compared Russian current (RC) with pulsed current (PC) effects after a training program. Objectives: We studied the effects of different neuromuscular electrical stimulation currents, RC, and PC on the neuromuscular system after a 6-week training period. Design: Blinded randomized controlled trial. Setting: Laboratory. Patients: A total of 27 male soccer players (age 22.2 [2.2] y, body mass 74.2 [10.0] kg, height 177 [0] cm, and body mass index 23.7 [2.9] kg/cm2 for the control group; 22.1 [3.1] y, 69.7 [5.7] kg, 174 [0] cm, and 23.0 [2.5] kg/cm for the PC group; and 23.0 [3.4] y, 72.1 [10.7] kg, 175 [0] cm, and 23.5 [3.4] kg/cm for the RC group) were randomized into 3 groups: (1) control group; (2) RC (2500 Hz, burst 100 Hz, and phase duration 200 μs); and (3) PC (100 Hz and 200 μs). Intervention: The experimental groups trained for 6 weeks, with 3 sessions per week with neuromuscular electrical stimulation. Main Outcome Measures: Maximal voluntary isometric contraction and evoked torque, muscle architecture, sensory discomfort (visual analog scale), and electromyographic activity were evaluated before and after the 6-week period. Results: Evoked torque increased in the RC (169.5% [78.2%], P < .01) and PC (248.7% [81.1%], P < .01) groups. Muscle thickness and pennation angle increased in the RC (8.7% [3.8%] and 16.7% [9.0%], P < .01) and PC (16.1% [8.0%] and 27.4% [11.0%], P < .01) groups. The PC demonstrated lower values for visual analog scale (38.8% [17.1%], P < .01). There was no significant time difference for maximal voluntary isometric contraction and root mean square values (P > .05). For all these variables, there was no difference between the RC and PC (P > .05). Conclusion: Despite the widespread use of RC in clinical practice, RC and PC training programs produced similar neuromuscular adaptations in soccer players. Nonetheless, as PC generated less perceived discomfort, it could be preferred after several training sessions.

The aim of the study was to evaluate the effects of 6 weeks training with different neuromuscular electrical stimulation (NMES) currents (medium alternated and low-frequency pulsed current) on muscle architecture and neuromuscular performance of competitive athletes. A double-blind controlled and randomized experimental study was carried out with 33 athletes (22.2±2.6 yrs, 74.7±9.8 kg, 176.8±6.0 cm), divided into 3 groups: mid-frequency current (MF, n=12), pulsed current (PC, n=11) and the control group (CG, n=10). Quadriceps maximal voluntary peak torque (PT) and corresponding vastus lateralis electromyographic activity, evoked torque (PT-NMES), vastus lateralis muscle thickness, fascicle length, pennation angle, and level of discomfort were assessed before and after the interventions. NMES training was performed 3 times per week and consisted of 18 sessions, 15 min/session, 6 s duration in each contraction interspersed with 18 s rest. After the training period, muscle thickness increased in the MF and PC groups (p<0.05). PT-NMES increased only in the PC group (p<0.05). All currents produced similar levels of discomfort (p>0.05). Quadriceps NMES training applied through alternated or pulsed currents produced similar effects in architecture and neuromuscular performance in competitive athletes.

Both currents induced similar neuromuscular fatigue. Clinicians can choose either PC or MF and expect similar treatment effects when the goal is to generate gains in muscle strength. Muscle Nerve 58: 293-299, 2018.