***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: OBJECTIVE To determine the effect of frequency of resistive training on gain in muscle strength and neuromuscular performance in healthy older adults . DESIGN A r and omized controlled trial with subjects assigned either to high-intensity resistance training 1 ( EX1 ) , 2 ( EX2 ) , or 3 ( EX3 ) days per week for 24 weeks or to a control group ( CO ) . SETTING An exercise facility at an academic medical center . SUBJECTS Forty-six community-dwelling healthy men ( n = 29 ) and women ( n = 17 ) aged 65 to 79 years . INTERVENTION Progressive resistance training consisting of three sets of eight exercises targeting major muscle groups of the upper and lower body , at 80 % of one-repetition maximum ( 1-RM ) for eight repetitions , either 1 , 2 , or 3 days per week . MEASURES Dynamic muscle strength ( 1-RM ) using isotonic equipment every 4 weeks , bone mineral density and body composition by dual energy X-ray absorptiometry ( DXA ) , and neuromuscular performance by timed chair rise and 6-meter backward t and em walk . RESULTS For each of the eight exercises , muscle strength increased in the exercise groups relative to CO ( P < .01 ) , with no difference among EX1 , EX2 and EX3 groups at any measurement interval . Percent change averaged 3.9 + /- 2.4 ( CO ) , 37.0 + /- 15.2 ( EX1 ) , 41.9 + /- 18.2 ( EX2 ) , and 39.7 + /- 9.8 ( EX3 ) . The time to rise successfully from the chair 5 times decreased significantly ( P < .01 ) at 24 weeks , whereas improvement in the 6-meter backward t and em walk approached significance ( P = .10 ) in the three exercise groups compared with CO . Changes in chair rise ability were correlated to percent changes in quadriceps strength ( r = -0.40 , P < .01 ) and lean mass ( r = -0.40 , P < .01 ) . CONCLUSIONS A program of once or twice weekly resistance exercise achieves muscle strength gains similar to 3 days per week training in older adults and is associated with improved neuromuscular performance . Such improvement could potentially reduce the risk of falls and fracture in older adults Abstract Fisher , G , McCarthy , JP , Zuckerman , PA , Bryan , DR , Bickel , CS , and Hunter , GR . Frequency of combined resistance and aerobic training in older women . J Strength Cond Res 27(7 ) : 1868–1876 , 2013—The aim of this study was to determine the optimal frequency of combined aerobic and resistance training for improving muscular strength ( MS ) , cardiovascular fitness ( CF ) , and functional tasks ( FTs ) in women older than 60 years . Sixty-three women were r and omly assigned to 1 of 3 exercise training groups . Group 1 performed 1 resistance exercise training ( RET ) and 1 aerobic exercise training ( AET ) session per week ( AET/RET 1 × wk−1 ) ; group 2 performed 2 RET and 2 AET sessions per week ( AET/RET 2 × wk−1 ) ; and group 3 performed 3 RET and 3 AET sessions per week ( AET/RET 3 × wk−1 ) . MS , CF , and FT measurements were made pretraining and 16 weeks posttraining . Repeated- measures analysis of variance indicated a significant time effect for changes in MS , CF , and FT , such that all improved after training . However , there were no significant training group or training group × time interactions . Sixteen weeks of combined AET/RET ( 1 × wk−1 , 2 × wk−1 , or 3 × wk−1 ) lead to significant improvements in MS , CF , exercise economy , and FT . However , there were no significant differences for MS , CF , or FT outcomes between groups PURPOSE The purpose of this study was to compare changes in maximal strength , power , and muscular endurance after 12 wk of periodized heavy-resistance training directly supervised by a personal trainer ( SUP ) versus unsupervised training ( UNSUP ) . METHODS Twenty moderately trained men aged 24.6 + /- 1.0 yr ( mean + /- SE ) were r and omly assigned to either the SUP group ( N = 10 ) or the UNSUP group ( N = 8) . Both groups performed identical linear periodized resistance training programs consisting of preparatory ( 10 - 12 repetitions maximum ( RM ) ) , hypertrophy ( 8 to 10-RM ) , strength ( 5 to 8-RM ) , and peaking phases ( 3 to 6-RM ) using free-weight and variable-resistance machine exercises . Subjects were tested for maximal squat and bench press strength ( 1-RM ) , squat jump power output , bench press muscular endurance , and body composition at week 0 and after 12 wk of training . RESULTS Mean training loads ( kg per set ) per week were significantly ( P < 0.05 ) greater in the SUP group than the UNSUP group at weeks 7 through 11 for the squat , and weeks 3 and 7 through 12 for the bench press exercises . The rates of increase ( slope ) of squat and bench press kg per set were significantly greater in the SUP group . Maximal squat and bench press strength were significantly greater at week 12 in the SUP group . Squat and bench press 1-RM , and mean and peak power output increased significantly after training in both groups . Relative local muscular endurance ( 80 % of 1-RM ) was not compromised in either group despite significantly greater loads utilized in bench press muscular endurance testing after training . Body mass , fat mass , and fat-free mass increased significantly after training in the SUP group . CONCLUSION Directly supervised , heavy-resistance training in moderately trained men result ed in a greater rate of training load increase and magnitude which result ed in greater maximal strength gains compared with unsupervised training Abstract Seventeen subjects performed resistance training of the leg extensor and flexor  muscle groups two ( 2/wk ) or three ( 3/wk ) times per week . Changes in the relative myosin heavy chain ( MHC ) isoform contents ( I , IIa and IIx ) of the vastus lateralis and isometric , isokinetic and squat-lift one-repetition maximum ( 1RM ) strength were compared between conditions after both a common training period ( 6 weeks ) and number of training sessions ( 18 ) . After 6 weeks and 18 sessions ( 9 weeks for the 2/wk group ) , increments in 1RM strength for the 3/wk and 2/wk groups were similar [ effect size ( ES ) differences ≈0.3 , 3/wk > 2/wk ] , whereas the 2/wk group presented greater isokinetic ( ES differences = 0.3–1.2 ) and isometric ( ES differences ≈0.7 ) strength increases than the 3/wk condition . A significant ( P < 0.05 ) increase in MHC IIa percentage was evident for the 2/wk group after 18 sessions . Both training groups exhibited a trend towards a reduction in the relative MHC IIx and an increase in MHC IIa contents ( ES range = 0.5–1.24 ) . However , correlations between changes in the strength and MHC profiles were weak ( r2 : 0.0–0.5 ) . Thus , isometric and isokinetic strength responses to variations in training frequency differed from 1RM strength responses , and changes in strength were not strongly related to alterations in relative MHC content Background : Strength training has been shown to benefit the health and function of older adults . Objective : To investigate whether one set of exercises performed once a week was as effective in increasing muscle strength as training twice a week . Methods : 18 subjects ( 7 women and 11 men ) aged 65–79 years were r and omly assigned to two groups . Both groups performed one set of exercises to muscular fatigue ; group 1 trained 1 day/week and group 2 trained 2 days/week on three lower and three upper body exercises for 9 weeks . The data were analysed using a mixed model 2 × 2 analysis of variance . Results : A significant main effect of time ( p<0.001 ) , but not group , on one-repetition maximum scores was observed . No significant interaction was observed between time and group and therefore no difference in strength changes between training once a week versus twice a week after 9 weeks . Conclusions : One set of exercises performed once weekly to muscle fatigue improved strength as well as twice a week in the older adult . Our results provide information that will assist in design ing strength-training programmes that are more time and cost efficient in producing health and fitness benefits for older adults Abstract Schoenfeld , BJ , Ratamess , NA , Peterson , MD , Contreras , B , and Tiryaki-Sonmez , G. Influence of resistance training frequency on muscular adaptations in well-trained men . J Strength Cond Res 29(7 ) : 1821–1829 , 2015—The purpose of this study was to investigate the effects of training muscle groups 1 day per week using a split-body routine ( SPLIT ) vs. 3 days per week using a total-body routine ( TOTAL ) on muscular adaptations in well-trained men . Subjects were 20 male volunteers ( height = 1.76 ± 0.05 m ; body mass = 78.0 ± 10.7 kg ; age = 23.5 ± 2.9 years ) recruited from a university population . Participants were pair matched according to baseline strength and then r and omly assigned to 1 of the 2 experimental groups : a SPLIT , where multiple exercises were performed for a specific muscle group in a session with 2–3 muscle groups trained per session ( n = 10 ) or a TOTAL , where 1 exercise was performed per muscle group in a session with all muscle groups trained in each session ( n = 10 ) . Subjects were tested pre- and post study for 1 repetition maximum strength in the bench press and squat , and muscle thickness ( MT ) of forearm flexors , forearm extensors , and vastus lateralis . Results showed significantly greater increases in forearm flexor MT for TOTAL compared with SPLIT . No significant differences were noted in maximal strength measures . The findings suggest a potentially superior hypertrophic benefit to higher weekly resistance training frequencies PURPOSE To compare the effects of the 16-wk training period ( 2 d.wk(-1 ) ) of resistance training alone ( S ) , endurance training alone ( E ) , or combined resistance ( once weekly ) and endurance ( once weekly ) training ( SE ) on muscle mass , maximal strength and power of the leg and arm extensor muscles , and maximal workload ( Wmax ) by using a incremental cycling test in older men . METHODS Thirty-one healthy men ( 65 - 74 yr ) were divided into three treatment groups to train 2x wk(-1 ) for 16 wk : S ( N = 10 ) , E ( N = 11 ) , or SE ( N = 10 ; 1x wk(-1 ) S + 1x wk(-1 ) E ) . The subjects were tested at 8-wk intervals ( i.e. , weeks 8 and 16 ) . RESULTS There were no significant differences between  S- and SE-induced muscle hypertrophy ( 11 % and 11 % ) and maximal strength ( 41 % and 38 % ) gains of the legs as well as between E- and SE-induced Wmax ( 28 % and 23 % ) gains . The increase in arm strength in S ( 36 % ) was greater than that recorded in SE ( 22 % ) and greater than that recorded in E ( 0 % ) . CONCLUSIONS Prolonged combined resistance and endurance training in older men seemed to lead to similar gains in muscle mass , maximal strength , and power of the legs as resistance training alone and to similar gains in maximal peak power output measured in an incremental cycling test as endurance training alone . These findings may have an effect on how resistance exercise is prescribed to older adults Purpose To determine if muscle growth is important for increasing muscle strength or if changes in strength can be entirely explained from practicing the strength test . Methods Thirty-eight untrained individuals performed knee extension and chest press exercise  for 8 wk . Individuals were r and omly assigned to either a high-volume training group ( HYPER ) or a group just performing the one repetition maximum ( 1RM ) strength test ( TEST ) . The HYPER group performed four sets to volitional failure ( ~8RM–12RM ) , whereas the TEST group performed up to five attempts to lift as much weight as possible one time each visit . Results Data are presented as mean ( 90 % confidence interval ) . The change in muscle size was greater in the HYPER group for both the upper and lower bodies at most but not all sites . The change in 1RM strength for both the upper body ( difference of −1.1 [ −4.8 , 2.4 ] kg ) and lower body ( difference of 1.0 [ −0.7 , 2.8 ] kg for dominant leg ) was not different between groups ( similar for nondominant ) . Changes in isometric and isokinetic torque were not different between groups . The HYPER group observed a greater change in muscular endurance ( difference of 2 [ 1,4 ] repetitions ) only in the dominant leg . There were no differences in the change between groups in upper body endurance . There were between-group differences for exercise volume ( mean [ 95 % confidence interval ] ) of the dominant ( difference of 11,049.3 [ 9254.6–12,844.0 ] kg ) leg ( similar for nondominant ) and chest press with the HYPER group completing significantly more total volume ( difference of 13259.9 [ 9632.0–16,887.8 ] kg ) . Conclusions These findings suggest that neither exercise volume nor the change in muscle size from training contributed to greater strength gains compared with just practicing the 
    Output:
    
Conclusions The results of the present systematic review and meta- analysis suggest a significant effect of RT frequency as higher training frequencies are translated into greater muscular strength gains .
However , these effects seem to be primarily driven by training volume because when the volume is equated , there was no significant effect of RT frequency on muscular strength gains .
Thus , from a practical st and point , greater training frequencies can be used for additional RT volume , which is then likely to result in greater muscular strength gains .
However , it remains unclear whether RT frequency on its own has significant effects on strength gain .
It seems that higher RT frequencies result in greater gains in muscular strength on multi-joint exercises in the upper body and in women , and , finally , in contrast to older adults , young individuals seem to respond more positively to greater RT frequencies .