Journal of strength and conditioning research
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J Strength Cond Res · Jan 2011
Randomized Controlled TrialThe influence of periodized resistance training on recreationally active males with chronic nonspecific low back pain.
The most common musculoskeletal health issue is chronic nonspecific low back pain (CLBP). CLBP increases pain and disability, which reduces quality of life (QoL). Generally, pain, disability, and QoL are improved with a moderate volume and intensity of physical activity. ⋯ The results indicate that middle- and old-age recreationally active males with CLBP respond similarly in magnitude to PRT, with improvements in all outcome measures (strength, pain, disability, QoL) across all time points of the study. Clinical significance (≥ 25%) in outcome measures was reached on most variables for the ME and OE groups. The results suggest that PRT may be effectively applied as rehabilitation for moderately trained recreational athletes with CLBP.
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J Strength Cond Res · Jul 2010
Randomized Controlled TrialThe effects of whole-body compression garments on prolonged high-intensity intermittent exercise.
The current study investigated the effects of wearing whole-body compression garments (WBCGs) on prolonged high-intensity intermittent exercise (PHIIE) performance. Eight male team-sport athletes ([X +/- SD] 20.6 +/- 1.2 years; 72.9 +/- 5.9 kg; 57.5 +/- 3.7 ml.kg.min) completed a prescribed 45-minute PHIIE protocol on a nonmotorized treadmill in randomly assigned WBCG and control (typical soccer apparel) conditions. Subjects were given verbal and visual cues for movement categories, and they followed set target speeds, except when instructed of a variable run or sprint where the aim was to run as fast as possible. ⋯ A similar likely increase was also observed in the average TOI of the WBCG condition (53.5 +/- 8.3% vs. 55.8 +/- 7.2%; 87:11:2%; and eta = 0.6). The current data demonstrated that wearing WBCGs likely increased physical performance, possibly because of improvements in muscle oxygenation and associated metabolic benefits. Therefore, wearing WBCGs during PHIIE may benefit the physical performance of team-sport athletes by likely metabolic changes within the muscle between high-intensity efforts.
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J Strength Cond Res · Jul 2010
Randomized Controlled TrialEffects of whole-body electromyostimulation on resting metabolic rate, body composition, and maximum strength in postmenopausal women: the Training and ElectroStimulation Trial.
We evaluated the effect of whole-body electromyostimulation (WB-EMS) during dynamic exercises over 14 weeks on anthropometric, physiological, and muscular parameters in postmenopausal women. Thirty women (64.5 +/- 5.5 years) with experience in physical training (>3 years) were randomly assigned either to a control group (CON, n = 15) that maintained their general training program (2 x 60 min.wk of endurance and dynamic strength exercise) or to an electromyostimulation group (WB-EMS, n = 15) that additionally performed a 20-minute WB-EMS training (2 x 20 min.10 d). Resting metabolic rate (RMR) determined from spirometry was selected to indicate muscle mass. ⋯ Isometric strength changes of the trunk extensors and leg extensors differed significantly (p < or = 0.006) between WB-EMS and CON (9.9% vs. -6.4%, ES = 1.53; 9.6% vs. -4.5%, ES = 1.43, respectively). In summary, adjunct WB-EMS training significantly exceeds the effect of isolated endurance and resistance type exercise on fitness and fatness parameters. Further, we conclude that for elderly subjects unable or unwilling to perform dynamic strength exercises, electromyostimulation may be a smooth alternative to maintain lean body mass, strength, and power.
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J Strength Cond Res · Mar 2010
Randomized Controlled Trial Comparative StudyAcute effects of Flexi-bar vs. Sham-bar exercise on muscle electromyography activity and performance.
This study was conducted to investigate whether the low-frequency (5-Hz) oscillatory vibration-like stimulus, purported to be delivered by exercising with Flexi-bar, acutely affects muscle activation and maximal voluntary contraction (MVC) force. Nine healthy men participated in 2 trials, separated by at least 1 week, during which 4 x 30-second sets of exercise were performed with either the Flexi bar or a Sham bar. Maximal voluntary contraction force for elbow flexion, elbow extension, and knee extension were measured before and after the exercise. ⋯ Knee extension MVC force significantly decreased after Flexi-bar exercise (-3 +/- 7%, p = 0.048) in parallel with reduced RF EMG amplitude (-8 +/- 5%, p = 0.04), but there were no acute residual effects on elbow flexion/extension MVC or arm and VL EMG muscle activity. Using Flexi bar during exercise provoked acute alterations in arm- and leg-muscle EMG parameters and maximum force-generating capacity, indicating greater fatigue development than when exercising with the Sham bar. The results of this study indicate that Flexi bar may therefore be used to impose a stronger training stimulus on the muscle during submaximal exercise.
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J Strength Cond Res · May 2009
Randomized Controlled Trial Comparative StudyComparison of two lower-body modes of endurance training on lower-body strength development while concurrently training.
The most recent American College of Sports Medicine (1998) recommendations for quantity and quality of exercise includes both resistance and endurance exercise components. Skeletal muscle adaptations to resistance-only and endurance-only programs may be different and possibly antagonistic when both types of training are imposed concurrently. The present study examined the effect of two different modes of lower-body endurance exercise (i.e., cycle ergometry and incline treadmill walking) on lower-body strength development with concurrent resistance training designed to improve lower-body strength (i.e., bilateral leg press 1 repetition maximum [RM]). ⋯ The findings confirm previous studies that reported attenuated strength development with concurrent resistance and endurance training compared with resistance-only training. More importantly, this study indicates that the mode of endurance exercise in concurrent training regimens may play a role in the development of strength. Specifically, it seems that cycling is superior to treadmill endurance training for an individual with the goal of developing strength in a multijoint movement (i.e., leg press or squat) in the lower-body because it more closely mimics the biomechanical movement of these exercises.