European journal of applied physiology, Mar 1, 2010
This study compared the first and second exercise bouts consisting of electrically evoked isometr... more This study compared the first and second exercise bouts consisting of electrically evoked isometric contractions for muscle damage profile. Nine healthy men (31±4 years) had two electrical muscle stimulation (EMS) bouts separated by 2 weeks. The knee extensors of one leg were stimulated by biphasic rectangular pulses (75 Hz, 400 μs, on–off ratio 5–15 s) at the knee joint angle of 100°(0°, full extension) to induce 40 isometric contractions, while the current amplitude was increased to maintain maximal force ...
The number of eccentric contractions is a factor affecting the magnitude of muscle damage; howeve... more The number of eccentric contractions is a factor affecting the magnitude of muscle damage; however, it is unknown whether set-repetition configurations for the same total number of eccentric contractions affect the muscle damage. The present study investigated whether different set-repetition configurations would result in different force output during eccentric exercise and different magnitude of muscle damage following the first and second exercise bouts. Ten non-resistance-trained men (26.1 ± 4.1 years) performed two bouts of eccentric exercise of the elbow flexors of each arm (4 bouts in total). One arm performed 3 sets of 10 maximal eccentric contractions (3 × 10) and the contralateral arm performed 10 sets of 3 maximal eccentric contractions (10 × 3), and each arm performed 20 sets of 3 maximal eccentric contractions (20 × 3) 4 weeks after the first bout. The order of the exercise (3 × 10, 10 × 3) and the use of arm (dominant, non-dominant) were counterbalanced amongst subjects. The torque produced over 30 eccentric contractions was similar between 3 × 10 and 10 × 3, and the changes in torque during 20 × 3 were similar between arms. Maximal voluntary contraction strength, range of motion, biceps brachii cross-sectional area and muscle soreness changed significantly (P < 0.05) following the exercise without significant differences between 3 × 10 and 10 × 3, and changes in the measures following 20 × 3 were similar between arms, except for range of motion (ROM). No significant difference in the changes in any measures except ROM was evident when compared between the first and second bouts. These results showed that changing the set-repetition configuration had little effect on muscle damage.
To examine the effect of progressive resistance training on muscle function, functional performan... more To examine the effect of progressive resistance training on muscle function, functional performance, balance, body composition, and muscle thickness in men receiving androgen deprivation for prostate cancer. Ten men aged 59-82 yr on androgen deprivation for localized prostate cancer undertook progressive resistance training for 20 wk at 6- to 12-repetition maximum (RM) for 12 upper- and lower-body exercises in a university exercise rehabilitation clinic. Outcome measures included muscle strength and muscle endurance for the upper and lower body, functional performance (repeated chair rise, usual and fast 6-m walk, 6-m backwards walk, stair climb, and 400-m walk time), and balance by sensory organization test. Body composition was measured by dual-energy x-ray absorptiometry and muscle thickness at four anatomical sites by B-mode ultrasound. Blood samples were assessed for prostate specific antigen (PSA), testosterone, growth hormone (GH), cortisol, and hemoglobin. Muscle strength (chest press, 40.5%; seated row, 41.9%; leg press, 96.3%; P < 0.001) and muscle endurance (chest press, 114.9%; leg press, 167.1%; P < 0.001) increased significantly after training. Significant improvement (P < 0.05) occurred in the 6-m usual walk (14.1%), 6-m backwards walk (22.3%), chair rise (26.8%), stair climbing (10.4%), 400-m walk (7.4%), and balance (7.8%). Muscle thickness increased (P < 0.05) by 15.7% at the quadriceps site. Whole-body lean mass was preserved with no change in fat mass. There were no significant changes in PSA, testosterone, GH, cortisol, or hemoglobin. Progressive resistance exercise has beneficial effects on muscle strength, functional performance and balance in older men receiving androgen deprivation for prostate cancer and should be considered to preserve body composition and reduce treatment side effects.
No previous studies have investigated the effect of lower body compression garments (CG) on runni... more No previous studies have investigated the effect of lower body compression garments (CG) on running performance in the heat. This study tested the hypothesis that CG would negatively affect running performance in the heat by comparing CG and non-CG conditions for running performance and physiological responses in hot and cold conditions. Ten male recreational runners (29.0 ± 10.0 years, $$ \dot{V}{\text{O}}_{ 2}
European journal of applied physiology, Mar 1, 2010
This study compared the first and second exercise bouts consisting of electrically evoked isometr... more This study compared the first and second exercise bouts consisting of electrically evoked isometric contractions for muscle damage profile. Nine healthy men (31±4 years) had two electrical muscle stimulation (EMS) bouts separated by 2 weeks. The knee extensors of one leg were stimulated by biphasic rectangular pulses (75 Hz, 400 μs, on–off ratio 5–15 s) at the knee joint angle of 100°(0°, full extension) to induce 40 isometric contractions, while the current amplitude was increased to maintain maximal force ...
The number of eccentric contractions is a factor affecting the magnitude of muscle damage; howeve... more The number of eccentric contractions is a factor affecting the magnitude of muscle damage; however, it is unknown whether set-repetition configurations for the same total number of eccentric contractions affect the muscle damage. The present study investigated whether different set-repetition configurations would result in different force output during eccentric exercise and different magnitude of muscle damage following the first and second exercise bouts. Ten non-resistance-trained men (26.1 ± 4.1 years) performed two bouts of eccentric exercise of the elbow flexors of each arm (4 bouts in total). One arm performed 3 sets of 10 maximal eccentric contractions (3 × 10) and the contralateral arm performed 10 sets of 3 maximal eccentric contractions (10 × 3), and each arm performed 20 sets of 3 maximal eccentric contractions (20 × 3) 4 weeks after the first bout. The order of the exercise (3 × 10, 10 × 3) and the use of arm (dominant, non-dominant) were counterbalanced amongst subjects. The torque produced over 30 eccentric contractions was similar between 3 × 10 and 10 × 3, and the changes in torque during 20 × 3 were similar between arms. Maximal voluntary contraction strength, range of motion, biceps brachii cross-sectional area and muscle soreness changed significantly (P < 0.05) following the exercise without significant differences between 3 × 10 and 10 × 3, and changes in the measures following 20 × 3 were similar between arms, except for range of motion (ROM). No significant difference in the changes in any measures except ROM was evident when compared between the first and second bouts. These results showed that changing the set-repetition configuration had little effect on muscle damage.
To examine the effect of progressive resistance training on muscle function, functional performan... more To examine the effect of progressive resistance training on muscle function, functional performance, balance, body composition, and muscle thickness in men receiving androgen deprivation for prostate cancer. Ten men aged 59-82 yr on androgen deprivation for localized prostate cancer undertook progressive resistance training for 20 wk at 6- to 12-repetition maximum (RM) for 12 upper- and lower-body exercises in a university exercise rehabilitation clinic. Outcome measures included muscle strength and muscle endurance for the upper and lower body, functional performance (repeated chair rise, usual and fast 6-m walk, 6-m backwards walk, stair climb, and 400-m walk time), and balance by sensory organization test. Body composition was measured by dual-energy x-ray absorptiometry and muscle thickness at four anatomical sites by B-mode ultrasound. Blood samples were assessed for prostate specific antigen (PSA), testosterone, growth hormone (GH), cortisol, and hemoglobin. Muscle strength (chest press, 40.5%; seated row, 41.9%; leg press, 96.3%; P < 0.001) and muscle endurance (chest press, 114.9%; leg press, 167.1%; P < 0.001) increased significantly after training. Significant improvement (P < 0.05) occurred in the 6-m usual walk (14.1%), 6-m backwards walk (22.3%), chair rise (26.8%), stair climbing (10.4%), 400-m walk (7.4%), and balance (7.8%). Muscle thickness increased (P < 0.05) by 15.7% at the quadriceps site. Whole-body lean mass was preserved with no change in fat mass. There were no significant changes in PSA, testosterone, GH, cortisol, or hemoglobin. Progressive resistance exercise has beneficial effects on muscle strength, functional performance and balance in older men receiving androgen deprivation for prostate cancer and should be considered to preserve body composition and reduce treatment side effects.
No previous studies have investigated the effect of lower body compression garments (CG) on runni... more No previous studies have investigated the effect of lower body compression garments (CG) on running performance in the heat. This study tested the hypothesis that CG would negatively affect running performance in the heat by comparing CG and non-CG conditions for running performance and physiological responses in hot and cold conditions. Ten male recreational runners (29.0 ± 10.0 years, $$ \dot{V}{\text{O}}_{ 2}
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