***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The purpose of this study was to examine the effect of isokinetic eccentric ( ECC ) and concentric ( CON ) training at two velocities [ fast , 180 ° s−1 ( 3.14 rad s−1 ) and slow,30 ° s−1(0.52 rad s−1 ) ] on muscle hypertrophy . Twenty-four untrained volunteers ( age 18–36 years ) participated in fast- ( n=13 ) or slow- ( n=11 ) velocity training , where they trained one arm eccentrically for 8 weeks followed by CON training of the opposite arm for 8 weeks . Ten subjects served as controls ( CNT ) . Subjects were tested before and after training for elbow flexor muscle thickness by sonography and isokinetic strength ( Biodex ) . Overall , ECC training result ed in greater hypertrophy than CON training ( P<0.01 ) . No significant strength or hypertrophy changes occurred in the CNT group . ECC ( 180 ° s−1 ) training result ed in greater hypertrophy  than CON ( 180 ° s−1 ) training and CON ( 30 ° s−1 ) training ( P<0.01 ) . ECC ( 30 ° s−1 ) training result ed in greater hypertrophy  than CON ( 180 ° s−1 ) training ( P<0.05 ) , but not CON ( 30 ° s−1 ) training . ECC ( 180 ° s−1 ) training result ed in the greatest increases in strength ( P<0.01 ) . We conclude that ECC fast training is the most effective for muscle hypertrophy and strength gain We have reported that the acute postexercise increases in muscle protein synthesis rates , with differing nutritional support , are predictive of longer-term training-induced muscle hypertrophy . Here , we aim ed to test whether the same was true with acute exercise-mediated changes in muscle protein synthesis . Eighteen men ( 21 ± 1 yr , 22.6 ± 2.1 kg/m(2 ) ; means ± SE ) had their legs r and omly assigned to two of three training conditions that differed in contraction intensity [ % of maximal strength ( 1 repetition maximum ) ] or contraction volume ( 1 or 3 sets of repetitions ) : 30%-3 , 80%-1 , and 80%-3 . Subjects trained each leg with their assigned regime for a period of 10 wk , 3 times/wk . We made pre- and posttraining measures of strength , muscle volume by magnetic resonance ( MR ) scans , as well as pre- and posttraining biopsies of the vastus lateralis , and a single postexercise ( 1 h ) biopsy following the first bout of exercise , to measure signaling proteins . Training-induced increases in MR-measured muscle volume were significant ( P < 0.01 ) , with no difference between groups : 30%-3 = 6.8 ± 1.8 % , 80%-1 = 3.2 ± 0.8 % , and 80%-3= 7.2 ± 1.9 % , P = 0.18 . Isotonic maximal strength gains were not different between 80%-1 and 80%-3 , but were greater than 30%-3 ( P = 0.04 ) , whereas training-induced isometric strength gains were significant but not different between conditions ( P = 0.92 ) . Biopsies taken 1 h following the initial resistance exercise bout showed increased phosphorylation ( P < 0.05 ) of p70S6 K only in the 80%-1 and 80%-3 conditions . There was no correlation between phosphorylation of any signaling protein and hypertrophy . In accordance with our previous acute measurements of muscle protein synthetic rates a lower load lifted to failure result ed in similar hypertrophy as a heavy load lifted to failure Ten healthy young men ( 21.0 + /- 1.5 yr , 1.79 + /- 0.1 m , 82.7 + /- 14.7 kg , means + /- SD ) participated in 8 wk of intense unilateral resistance training ( knee extension exercise ) such that one leg was trained ( T ) and the other acted as an untrained ( UT ) control . After the 8 wk of unilateral training , infusions of L-[ring-d(5)]phenylalanine , L-[ring-(13)C(6)]phenylalanine , and d(3)-alpha-ketoisocaproic acid were used to measure mixed muscle protein synthesis in the T and UT legs by the direct incorporation method [ fractional synthetic rate ( FSR ) ] . Protein synthesis was determined at rest as well as 4 h and 28 h after an acute bout of resistance exercise performed at the same intensity relative to the gain in single repetition maximum before and after training . Training increased mean muscle fiber cross-sectional area only in the T leg ( type I : 16 + /- 10 % ; type II : 20 + /- 19 % , P < 0.05 ) . Acute resistance exercise increased muscle protein FSR in both legs at 4 h ( T : 162 + /- 76 % ; UT : 108 + /- 62 % , P < 0.01 vs. rest ) with the increase in the T leg being significantly higher than in the UT leg at this time ( P < 0.01 ) . At 28 h postexercise , FSR in the T leg had returned to resting levels ; however , the rate of protein synthesis in the UT leg remained elevated above resting ( 70 + /- 49 % , P < 0.01 ) . We conclude that resistance training attenuates the protein synthetic response to acute resistance exercise , despite higher initial increases in FSR , by shortening the duration for which protein synthesis is elevated The authors investigated the effects of low-intensity resistance training on muscle size and strength in older men and women . Thirty-five participants ( age 59 - 76 yr ) were r and omly assigned to 2 groups and performed low-intensity ( 50 % of 1-repetition maximum ) knee-extension and -flexion exercises with either slow movement and tonic force generation ( LST ; 3-s eccentric , 3-s concentric , and 1-s isometric actions with no rest between repetitions ) or normal speed ( LN ; 1-s concentric and 1-s eccentric actions with 1-s rests between repetitions ) twice a week for 12 wk ( 2-wk preparation and 10-wk intervention ) . The LST significantly increased thigh-muscle thickness , as well as isometric knee-extension and -flexion strength . The LN significantly improved strength , but its hypertrophic effect was limited . These results indicate that even for older individuals , the LST can be an effective method for gaining muscle mass and strength Dual-energy X-ray absorptiometry ( DEXA ) is reported to be inferior to computed tomography ( CT ) to measure changes in appendicular soft tissue composition . We compared CT- and DEXA-measured thigh muscle and fat mass to evaluate the r and om and systematic discrepancies between these two methods . Thigh skeletal muscle area ( single-slice CT ) was suboptimally ( r(2 ) = 0.74 , P < 0.0001 ) related to DEXA-measured thigh fat-free mass ( FFM ) . In contrast , thigh muscle and adipose tissue volumes ( multislice CT ) were highly related to DEXA-measured thigh FFM and fat ( both r(2 ) = 0.96 , P < 0.0001 ) .  DEXA-measured leg fat was significantly less than multislice-CT-measured leg adipose tissue volume , whereas multislice-CT-measured leg muscle mass was less ( P < 0.0001 ) than DEXA-measured leg FFM . The systematic discrepancies between the two approaches were consistent with the 10 - 15 % nonfat components of adipose tissue . In conclusion ,  CT and DEXA measures of appendicular soft tissue are highly related . Systematic differences between DEXA and CT likely relate to the underlying principles of the techniques A two-arm , prospect i ve , r and omized , controlled trial study was conducted to investigate the effects of movement velocity during progressive resistance training ( PRT ) on the size and contractile properties of individual fibers from human vastus lateralis muscles . The effects of age and sex were examined by a design that included 63 subjects organized into four groups : young ( 20 - 30 yr ) men and women , and older ( 65 - 80 yr ) men and women . In each group , one-half of the subjects underwent a traditional PRT protocol that involved shortening contractions at low velocities against high loads , while the other half performed a modified PRT protocol that involved contractions at 3.5 times higher velocity against reduced loads . Muscles were sample d by needle biopsy before and after the 14-wk PRT program , and functional tests were performed on permeabilized individual fiber segments isolated from the biopsies . We tested the hypothesis that , compared with low-velocity PRT , high-velocity PRT results in a greater increase in the cross-sectional area , force , and power of type 2 fibers . Both types of PRT increased the cross-sectional area , force , and power of type 2 fibers by 8 - 12 % , independent of the sex or age of the subject . Contrary to our hypothesis , the velocity at which the PRT was performed did not affect the fiber-level outcomes substantially . We conclude that , compared with low-velocity PRT , resistance training performed at velocities up to 3.5 times higher against reduced loads is equally effective for eliciting an adaptive response in type 2 fibers from human skeletal muscle PURPOSE To compare effects on strength in the early phase of resistance training with one or three sets and fast or slow speeds . METHODS A total of 115 healthy , untrained subjects were r and omized to a control group or one of four training groups : one set fast ( approximately 140 degrees.s(-1 ) ) , three sets fast , one set slow ( approximately 50 degrees.s(-1 ) ) , or three sets slow . All subjects attended training 3 x wk(-1 ) for 6 wk . Subjects in the training groups performed unilateral elbow flexion contractions with a target six- to eight-repetition maximum load . Control subjects sat at the training bench but did not train . One repetition maximum strength , arm circumference , and biceps skinfold thickness were measured before and after training . RESULTS One slow set increased strength by 25 % ( 95 % CI 13 - 36 % , P < 0.001 ) . Three sets of training produced greater increases in strength than one set ( difference = 23 % of initial strength , 95 % CI 12 - 34 % , P < 0.001 ) and fast training result ed in a greater increase in strength than slow training ( difference = 11 % , 95 % CI 0.2 - 23 % , P = 0.046 ) . The interaction between sets and speed was negative ( -15 % ) and of borderline significance ( P = 0.052 ) , suggesting there is a benefit of training with three sets or fast speeds , but there is not an additive benefit of training with both . CONCLUSIONS Three sets of exercise produce twice the strength increase of one set in the early phase of resistance training . Training fast produces greater strength increases than training slow ; however , there does not appear to be any additional benefit of training with both three sets and fast contractions We previously reported that low‐intensity [ 50 % of one repetition maximum ( 1RM ) ] resistance training with slow movement and tonic force generation ( LST ) causes muscle hypertrophy and strength gain in older participants . The aim of this study was to determine whether resistance training with slow movement and much more reduced intensity ( 30%1RM ) increases muscle size and strength in older adults . Eighteen participants ( 60–77 years ) were r and omly assigned to two groups . One group performed very low‐intensity ( 30 % 1RM ) knee extension exercise with continuous muscle contraction ( LST : 3‐s eccentric , 3‐s concentric , and 1‐s isometric actions with no rest between each repetition ) twice a week for 12 weeks . The other group underwent intermitted muscle contraction ( CON : 1‐s concentric and 1‐s eccentric actions with 1‐s rest between each repetition ) for the same time period . The 1RM , isometric and isokinetic strengths , and cross‐sectional image of the mid‐thigh obtained by magnetic resonance imaging were examined before and after the intervention . LST  significantly increased the cross‐sectional area of the quadriceps muscle ( 5·0 % , P<0·001 ) and isometric and isokinetic knee extension strengths ( P<0·05 ) . CON failed to increase muscle size ( 1·1 % , P = 0·12 ) , but significantly improved its strength ( P<0·05 ) . These results indicate that even if the intensity is as low as 30 % 1RM , LST can increase muscle size and strength in healthy older adults . The large total contraction time may be related to muscle hypertrophy and strength gain . LST would be useful for preventing sarcopenia in older individuals The purpose of this study was to investigate the effects of a six-week ( 16 - 17 training sessions ) low velocity resistance training program ( LV ) on various performance measures as compared to a traditional strength ( TS ) and a traditional muscular endurance ( TE ) resistance training program . Thirty-four healthy adult females ( 21.1 ± 2.7 y ) were r and omly divided into 4 groups : control ( C ) , TS , TE , and LV . Workouts consisted of 3 exercises : leg press ( LP ) , back squat ( SQ ) , and knee extension ( KE ) . Each subject was pre- and posttested for 1 repetition maximum ( 1RM ) , muscular endurance , maximal oxygen consumption ( VO2max ) , 
    Output:
    
Results Results indicate that hypertrophic outcomes are similar when training with repetition duration s ranging from 0.5 to 8 s. Conclusions From a practical st and point it would seem that a fairly wide range of repetition duration s can be employed if the primary goal is to maximize muscle growth .