vendex and Weight-Loss

Exercise training (EX) and weight loss (WL) improve lower extremity physical function (LEPF) in older overweight women; however, effects on rate of torque development (RTD) are unknown. This study aimed to determine the effects of WL + EX or WL alone on RTD, and relatedly LEPF, in overweight older women. Leg strength was assessed using isokinetic dynamometry, and RTD was calculated (RTD200 = RTD at 200 ms, RTDPeak = peak RTD, T2P = time to 1st peak). LEPF was determined via clinical functional tasks. Women (n = 44, 69.1 ± 3.6 years, 30.6 ± 4.3 kg/m2) completed a 6-month trial in EX + WL or WL groups with similar weight loss (-9.8 ± 4.2%, p > .95). EX + WL had greater improvements in (a) most LEPF tasks (p < .001) and (b) RTD200, compared with WL (36% vs. -16%, p = .031); no other RTD parameters differed. Changes in RTD parameters and LEPF were not related (all p > .05). RTD is responsive to EX but is not associated with LEPF in older women.

Topics: Aged; Exercise; Female; Humans; Muscle Strength; Overweight; Torque; Weight Loss

Few investigations have evaluated isokinetic torque after a period of weight loss in wrestlers. Thus, the current study sought to investigate the effects of gradual weight loss in the precompetitive period on isokinetic peak torque in the upper and lower limbs and body composition in wrestling athletes.. Eight elite athletes participated in the study (mean age 20.8±3.1 years). The athletes visited the laboratory on 2 occasions: during the period of weight maintenance (baseline) and during weight loss, in the precompetitive period (post). The variables analyzed were body composition through air displacement plethysmography (BOD POD) and peak torque (PT) of knee flexion and extension movements, and internal and external shoulder rotation in concentric action, at speeds of 60°/s and 180°/s, determined using an isokinetic dynamometer (Biodex Medical Systems; Shirley, NY, USA).. A significant decrease was observed in body composition values, except lean mass. No significant differences were observed in the PT of the movements analyzed: Shoulder internal rotation (60°/s P=0.825; 180°/s P=0.245) and external rotation (60°/s P=0.149; 180°/s P=0.163) and knee extension (60°/s P=0.086; 180°/s P=0.630) and flexion (60°/s P=0.310; 180°/s P=0.239).. Gradual weight loss did not affect the production of torque in the wrestlers before a competition. In addition, gradual weight loss contributed to a reduction in body fat, associated with an increase in percentage lean body mass.

Topics: Adipose Tissue; Adolescent; Adult; Athletes; Body Composition; Body Weight; Female; Humans; Male; Muscle Strength; Rotation; Shoulder; Torque; Weight Loss; Wrestling; Young Adult

We examined the hypothesis that metabolic surgery-induced massive weight loss causes mass-driven and behavioral adaptations in the kinematics and kinetics of obese gait. Gait analyses were performed at three time points over ∼1 yr in initially morbidly obese (mass: 125.7 kg; body mass index: 43.2 kg/m(2)) but otherwise healthy adults. Ten obese adults lost 27.1% ± 5.1 (34.0 ± 9.4 kg) weight by the first follow-up at 7.0 mo (±0.7) and 6.5 ± 4.2% (8.2 ± 6.0 kg) more by the second follow-up at 12.8 mo (±0.9), with a total weight loss of 33.6 ± 8.1% (42.2 ± 14.1 kg; P = 0.001). Subjects walked at a self-selected and a standard 1.5 m/s speed at the three time points and were also compared with an age- and gender-matched comparison group at the second follow-up. Weight loss increased swing time, stride length, gait speed, hip range of motion, maximal knee flexion, and ankle plantarflexion. Weight loss of 27% led to 3.9% increase in gait speed. An additional 6.5% weight loss led to an additional 7.3% increase in gait speed. Sagittal plane normalized knee torque increased and absolute ankle and frontal plane knee torques decreased after weight loss. We conclude that large weight loss produced mechanical plasticity by modifying ankle and knee torques and gait behavior. There may be a weight loss threshold of 30 kg limiting changes in gait kinematics. Implications for exercise prescription are also discussed.

Topics: Adult; Ankle Joint; Biomechanical Phenomena; Exercise Test; Follow-Up Studies; Gait; Hip Joint; Humans; Kinetics; Knee Joint; Obesity, Morbid; Torque; Walking; Weight Loss

Obesity is associated with an increased risk of falls and injury. Weight loss and strength training can be beneficial to balance, but knowing which is more beneficial would lead to interventions designed for maximal benefit in balance.. The goal of this study was to investigate the relative effects of weight loss and strength training on balance recovery using an ankle strategy.. We used a combination of experimental testing and forward dynamic simulations. Nine male subjects (body mass index = 30.1-36.9 kg x m(-2)) were released from a forward lean and attempted to recover balance using an ankle strategy. Lean angle was increased until subjects required a step or hip flexion to recover balance. The maximum lean angle, thetamax, was used as the measure of balance recovery capability. Experimental data served as inputs to an inverted pendulum model of balance recovery. Multiple simulations were performed to determine the effects of weight and strength on thetamax.. Both strength training and weight loss increased thetamax. Comparing the percent changes in weight and strength required to increase thetamax, a targeted amount revealed differences in intervention potency. For example, to increase thetamax by 1 degree, an 8.6 +/- 0.8% decrease in weight or 15.3 +/- 1.1% increase in strength was required. The differences in efficacy between the interventions became more apparent as larger increases in thetamax were targeted.. Balance recovery can improve with weight loss or strength gain, but a smaller amount of weight loss is needed than strength gain for a targeted improvement in balance recovery. This suggests that weight loss is a more potent intervention than strength training in improving balance recovery using an ankle strategy.

Topics: Accidental Falls; Adult; Analysis of Variance; Ankle; Body Mass Index; Electromyography; Humans; Male; Muscle Strength; Obesity; Postural Balance; Risk Factors; Torque; Virginia; Weight Loss