Integrated electromyography and performance outcomes to inertial resistance exercise.

Integrated electromyography (IEMG) and performance outcomes from resistance exercise may be influenced by gender, repetition order, and contractile mode. A novel strength training apparatus employing inertial resistance operates unlike standard exercise equipment and may therefore evoke different IEMG and performance outcomes. Subjects performed 3-set, 10-repetition calf press workouts on an inertial device while IEMG and flywheel velocity were recorded. Dependent variables were examined with 2 (men, women) x 2 (first vs. 10th repetition) x 2 (concentric, eccentric) analyses of variance. Performance outcomes showed gender-by-repetition and gender-by-contractile-mode interactions, with men's 10th-repetition and men's concentric data, respectively, causing these effects. Medial gastrocnemius (MG) IEMG showed a gender-by-repetition interaction resulting from men's first-repetition data. Greater 10th-repetition performance despite higher first-repetition MG IEMG may result from heightened triceps surae elastic energy utilization and/or maintained cross-bridges during transitions from lengthening-to-shortening actions. Inertial strength training may improve performance outcomes without additional motor unit recruitment.

Can albuterol help resistance exercise attenuate unloading-induced bone loss?

Hind-limb-suspended rats incur attenuated bone loss with beta(2)-agonists, and humans note similar changes with concurrent resistance exercise. To examine if the beta(2)-agonist albuterol helps resistance exercise reduce unloading-induced bone loss, human subjects performed 40 days of unilateral limb suspension with their left legs, otherwise refraining from normal ambulatory activity. While performing left leg strength training 3 days.week(-1), subjects received a concurrent placebo or albuterol (16 mg.day(-1)) treatment. Left leg muscle and bone changes were analyzed with 2 x 2 analyses of covariance (ANCOVAs). Mechanical loading values were calculated from workouts and compared using a 2 x 5 analysis of variance (ANOVA) and a Tukey post hoc test. The resistance exercise-albuterol assignment evoked significant (p < 0.05) left leg bone mineral content (BMC) gains (+2.24%) after 40 days. During the final unloading days, the resistance exercise-placebo group's mechanical loading data declined (-13.91%) significantly (p < 0.05) versus initial values. A resistance exercise-albuterol assignment likely increased BMC by maintaining the mechanical loading stimulus.

Net caloric cost of a 3-set flywheel ergometer resistance exercise paradigm.

Subjects (n = 23) performed three 3 x 8 seated leg press workouts on a flywheel ergometer to note the net caloric cost. This study's purpose was to examine net caloric cost as a function of total work on an inertial resistance exercise device offering more eccentric loading than conventional isotonic weight training equipment. High intraclass correlations for net caloric cost (0.89) and total work (0.94) result from data collected from 3 workouts. Average total work and net caloric cost values reveal a significant (r = 0.62, p < 0.05) correlation yielding the following equation: predicted net caloric cost = 33.2 + 0.006014331 (total work). Current study data also show favorable net caloric cost (1.24 kcal x kg(-1) x d(-1)), exercise efficiency (9.48 kcal x 10(-3) per joule), and estimated mechanical loading (65 W min x kg(-1) LBM x d(-1)) values. The results of the current study serve as baseline knowledge for exercise prescriptions pertaining to net caloric cost, exercise efficiency, and mechanical loading using this device.