title: Early plateaus of power and torque gains during high- and low-speed resistance training of older women. Optimal load for increasing muscle power during explosive resistance training in older adults. Effect of power-training intensity on the contribution of force and velocity to peak power in older adults. Lower extremity power training in elderly subjects with mobility limitations: a randomized controlled trial Increased Velocity Exercise Specific to Task (InVEST) training: a pilot study exploring effects on leg power, balance, and mobility in community-dwelling older women. Cycling as a novel approach to resistance training increases muscle strength, power, and selected functional abilities in healthy older women. Enhancing quality of life in older adults: A comparison of muscular strength and power training Strength versus muscle power-specific resistance training in community-dwelling older adults. Increased velocity exercise specific to task training versus the National Institute on Aging's strength training program: changes in limb power and mobility. Lower extremity muscle function after strength or power training in older adults. Power training improves balance in healthy older adults. Effect of high versus low-velocity resistance training on muscular fitness and functional performance in older men Effect of strength and power training on physical function in community-dwelling older adults. Changes in Function and Disability After Resistance Training: Does Velocity Matter?: A Pilot Study High-velocity resistance training increases skeletal muscle peak power in older women. Neuromuscular and balance responses to flywheel inertial versus weight training in older persons.
abstract: Periodization is the most effective approach to resistance training ; however , optimal cycle lengths for older persons are not known . This study examined the duration s of performance increments , plateaus , and decrements in women , ages 61 - 75 yr , over 9 wk of isokinetic training .  After a 2-wk adaptation cycle , older women trained for either power ( PWR ; 4.73 rad/s ; n = 9 ) or strength ( STR ; 1.05 rad/s ; n = 8) , 3 days/wk with a 1-day recovery between sessions . Repetitions were initially selected to equilibrate work volume between groups . Average power ( AP ) , peak torque ( PT ) , and total work ( TW ) curves were analyzed using forward and backward stepwise regression to ascertain inflections and plateaus . PWR training produced the highest AP , whereas STR produced the highest PT . TW was similar between groups . The AP curves of the PWR group initially showed a steep positive slope and then plateaued during week 3 . The right leg plateau lasted throughout training , whereas the left leg showed another positive inflection during weeks 7 and 8 . PWR group TW curves showed positive slopes throughout training . STR group PT curves for both legs showed initial positive slopes peaking between weeks 3 and 4 and declining thereafter . The TW curves for both legs showed slight negative slopes across the first 2 wk , steep positive slopes during weeks 3 - 6 , and a final plateau . Because improvements plateau early during PWR and STR training , isokinetic training prescriptions for optimizing strength and power improvements in older persons should use cycles of 3 - 4 wk to maximize gains BACKGROUND Muscle power ( force x velocity ) recedes at a faster rate than strength with age and may also be a stronger predictor of fall risk and functional decline . The optimal training paradigm for improving muscle power in older adults is not known , although some literature suggests high velocity , low load training is optimal in young adults . METHODS One hundred twelve healthy older adults ( 69 + /- 6 years ) were r and omly assigned to either explosive resistance training at 20 % ( G20 ) , 50 % ( G50 ) , or 80 % ( G80 ) one repetition maximum ( 1RM ) for 8 - 12 weeks or to a nontraining control group ( CON ) . Participants trained twice per week ( five exercises ; three sets of eight rapidly concentric and slow eccentric repetitions ) using pneumatic resistance machines . Repeated- measures analysis of variance and covariance ( ANOVA and ANCOVA ) were used to determine the effects of training . RESULTS Average peak power increased significantly and similarly in G80 ( 14 + /- 8 % ) , G50 ( 15 + /- 9 % ) , and G20 ( 14 + /- 6 % ) compared to CON ( 3 + /- 6 % ) ( p < .0001 ) . By contrast , a positive dose-response relationship with training intensity was observed for relative changes in average strength ( r = .40 , p = .0009 ) and endurance ( r = .43 , p = .0005 ) . Average strength increased in G80 ( 20 + /- 7 % ) , G50 ( 16 + /- 7 % ) , and G20 ( 13 + /- 7 % ) compared to CON ( 4 + /- 4 % ) ( p < .0001 ) . Average muscle endurance increased in G80 ( 185 + /- 126 % , p < .0001 ) , G50 ( 103 + /- 75 % , p = .0004 ) , and G20 ( 82 + /- 57 % , p = .0078 ) compared to CON ( 28 + /- 29 % ) . CONCLUSION Peak muscle power may be improved similarly using light , moderate , or heavy resistances , whereas there is a dose-response relationship between training intensity and muscle strength and endurance changes . Therefore , using heavy loads during explosive resistance training may be the most effective strategy to achieve simultaneous improvements in muscle strength , power , and endurance in older adults OBJECTIVE To determine the effect of training intensity on the contributions of force and velocity to improvements in peak power ( PP ) after explosive resistance training in older adults . METHODS 112 healthy older adults ( 69 + /- 6 yr ) were r and omized to explosive resistance training at 20 % ( G20 ) , 50 % ( G50 ) , or 80 % ( G80 ) maximal strength ( 1-repetition maximum ) for 8 - 12 wk ( twice weekly , 5 exercises , 3 sets of 8 explosive concentric/slow eccentric repetitions ) using pneumatic resistance machines or a nontraining control group ( CON ) . RESULTS Force at peak power ( FPP ) increased significantly and similarly among training groups compared with CON . Velocity at peak power ( VPP ) did not improve significantly and remained similar between all groups . Force contributed significantly more to PP production in G80 and G50 than in CON . The change in PP was independently predicted by changes in fat-free mass in G80 and by changes in both FPP and VPP in G50 and G20 . CONCLUSION Explosive resistance training in older adults results in the ability to produce higher PP outputs with heavier loads without loss of movement velocity . Moderate- to high-intensity training induced a greater relative contribution of force to PP production in this cohort Background and aims : This study investigated whether high-velocity high-power training ( POW )  improved lower extremity muscle power and quality in functionally-limited elders greater than traditional slow-velocity progressive resistance training ( STR ) . Methods : Fifty-seven community-dwelling older adults aged 74.2±7 ( range 65–94 yrs ) , Short Physical Performance Battery score 7.7±1.4 , were r and omized to either POW ( n=23 ) ( 12 females ) , STR ( n=22 ) ( 13 females ) or a control group of lower extremity stretching ( CON ) ( n=12 ) ( 6 females ) . Training was performed three times per week for 12 weeks and subjects completed three sets of double leg press and knee extension exercises at 70 % of the one repetition maximum ( 1RM ) . Outcome measures included 1RM strength and peak power ( PP ) . Total leg lean mass was determined using dual-energy X-ray absorptiometry to estimate specific strength and specific PP . Results : During training , power output was consistently higher in POW compared to STR for knee extension ( ∼2.3-fold ) and leg press ( ∼2.8-fold ) exercises ( p<0.01 ) . Despite this , PP and specific PP of the knee extensors increased similarly from baseline in POW and STR compared to CON ( p<0.01 ) , and no significant time-group interaction occurred for PP of the leg extensors . However , gains in leg press specific PP were significantly greater in POW compared to both STR and CON ( p<0.05 ) . Total leg lean mass did not change within any group . Conclusions : A short-term intervention of high-velocity power training and traditional slow-velocity progressive resistance training yielded similar increases of lower extremity power in the mobility-impaired elderly . Neuromuscular adaptations to power training , rather than skeletal muscle hypertrophy , may have facilitated the improvements in muscle quality . Additional studies are warranted to test the efficacy of power training in older individuals with compromised physical functioning OBJECTIVES To evaluate a dynamic form of weighted vest exercise suitable for home use and design ed to enhance muscle power , balance , and mobility . DESIGN A single-blind , r and omized , controlled trial . SETTING Outpatient exercise research facility situated within an academic long-term care center . PARTICIPANTS Twenty-one community-dwelling women aged 70 and older with a Short Physical Performance Battery ( SPPB ) score between 4 and 10 ( out of 12 ) . INTERVENTIONS Subjects were r and omized into a progressive resistance-training program using weighted vests for resistance with exercises design ed to be specific to mobility tasks and have a component performed at the fastest possible velocity ( Increased Velocity Exercise Specific to Task ( InVEST ) , n=11 ) or a control exercise group ( control , n=10 ) , which performed slow-velocity , low-resistance exercise . Both groups exercised three times a week for 12 weeks . MEASUREMENTS Changes in muscle power , balance , and physical performance were compared . RESULTS In comparison to control group , InVEST group manifested significant improvements ( P<.05 ) in leg power across measurements obtained at 75 % to 90 % of the one-repetition maximum . Both groups demonstrated significant improvements in chair st and and SPPB score from baseline , and the InVEST group showed significant improvements in gait speed and chair st and from baseline ( P<.05 ) . InVEST produced significantly greater changes in chair st and time than control ( P<.05 ) . CONCLUSION InVEST training appears be an effective means of enhancing leg power and chair rise in this population and is worthy of further investigation as a means of enhancing balance and mobility Cycling on a mechanically braked cycle ergometer was used as a novel approach to compare the effects of three different 16-wk resistance-training programs on isometric force , power output , and selected functional abilities in 31 healthy 65- to 74-yr-old women . Training was conducted three times per week . During each session , individuals of the speed group performed 8 sets of 16 pedal revolutions at 40 % of the maximal resistance to complete two revolutions ( 2 RM ) ; strength group performed 8 sets of 8 revolutions at 80 % of 2 RM ; and combination group performed 4 sets of 16 revolutions at 40 % and 4 sets of 8 revolutions at 80 % of 2 RM . During each set , all participants were required to pedal as fast as possible with a 2-min interval between sets . All training groups significantly increased force , power , and functional abilities ( maximal treadmill walking speed , vertical jumping , and box stepping ) at week 8 ( in the range from 6.5 to 20.8 % ) with no further improvement at week 16 ( except maximal treadmill walking speed ) , but no significant differences were observed between the three groups . The novel approach to performing both low- and high-resistance training , based on the use of a cycle ergometer , has been shown to be effective in improving strength , power , and functional abilities in a group of healthy women . Even fit older women can still improve in functional abilities . Interestingly , the " high-speed " and " low-speed " programs induced an increase in both power and strength of similar magnitude Background Although progressive resistance strength training ( ST ) has been found to improve various measures of physical functioning in older adults , the benefit to quality of life is unclear . Additionally , recent evidence suggests that high velocity power training ( PT ) may be more beneficial for physical functioning than ST , but it is not known whether this type of training impacts quality of life . The purpose of this study was to compare changes in multiple measures of quality of life result ing from ST vs. PT in older adults . A no exercise group was also included as control comparison condition . Methods Forty-five older adults ( M age = 74.8 years ; SD = 5.7 ) were r and omly assigned to either a ) PT , b ) ST , or c ) control group ( no exercise ) . Measures of self-efficacy ( SE ) , satisfaction with physical function ( SPF ) , and the Satisfaction with Life Scale ( SWL ) were assessed at baseline and following training . The resistance training conditions met 3 times per week for 12 weeks at an intensity of 70 % 1 repetition maximum . Results A series of ANCOVA 's comparing between group differences in change and controlling for baseline values revealed significant group differences in all three measures : SE ( F(2,31 ) = 9.77 ; p < .001 ) ; SPF ( F(2,32 ) = 3.36 ; p = .047 ) ; SWL ( F(2,31 ) = 4.76 ; p = .016 ) . Follow up analyses indicated that the PT group reported significantly more change in SE , SPF , and SWL than the control group whereas the ST group reported greater change than the control group only in SE . Conclusion These pilot data indicate that high velocity power training may influence multiple levels of quality of life over and above the benefits gained through traditional strength training BACKGROUND Loss of muscle power due to normal aging has greater functional impact than loss of strength alone . The present study compared two resistance training programs , one aim ed at enhancing muscle power and one at increasing muscle strength , on muscle function and functional performance in older adults . METHODS Sixty-seven healthy , independent older adults ( 65 - 84 years ) were r and omized to a high-velocity varied resistance ( HV ) , constant resistance ( ST ) , or nontraining control ( CO ) group . Participants trained twice weekly for 24 weeks using six exercises .  Dynamic and isometric muscle strength , muscle power , movement velocity , muscle endurance , and a battery of functional performance tasks were assessed . Secondary outcomes included body composition , quality of life , and balance confidence . RESULTS Muscle strength increased significantly ( p < .001 ) and similarly in the training groups compared to controls ( HV , 51.0 + /- 9.0 % ; ST , 48.3 + /- 6.8 % ; CO , 1.2 + /- 5.1 % ) . Peak muscle power also increased with training ( p < .05 ) , with no difference between training groups . The change in peak power was 50.5 + /- 4.1 % , 33.8 + /- 3.8 % , and -2.5 + /- 3.9 % in the HV , ST , and CO groups , respectively . Training also improved selected functional performance tasks in the HV and ST groups compared to controls ( p < .05 ) , and the HV group reported improved quality of life ( p = .018 ) . CONCLUSION Muscle power and muscle strength improved similarly using either resistance training protocol , and these changes were accompanied by improvements in several functional performance tasks . However , improvements in the HV group occurred with less total work performed per training session BACKGROUND This study was design ed to evaluate the benefits of InVEST ( Increased Velocity Specific to Task ) training on limb power and mobility among mobility-limited older adults . METHODS We conducted a single blinded , r and omized controlled trial among 138 mobility-limited community-dwelling older adults , evaluating two 16-week supervised exercise programs . The intervention group participated in InVEST training , and the control group participated in the National Institute on Aging 's ( NIA ) strength training program . Primary outcomes were changes in limb power per kilogram and mobility performance as measured by the Short Physical Performance Battery ( SPPB ) . RESULTS After 16 weeks , InVEST produced significantly greater improvements in limb power than NIA ( p=.02 ) . There was no significant difference in strength improvements . Both groups had significant changes in SPPB of greater than 1 unit . Self-reported function was also significantly improved in both groups . Differences between groups were not statistically different . In a post hoc analysis when participants were categorized by the manifestation of baseline leg velocity impairments ( N=68 ) , InVEST training produced effect size differences in SPPB that were clinical ly meaningful ( SPPB Group x Time difference 0.73 units , p=.05 ) . CONCLUSIONS Among mobility-limited older adults , both NIA and InVEST produce robust changes in observed physical performance and self-reported function . These improvements were not meaningfully different by statistical or clinical criteria . Compared with NIA , InVEST training produced greater improvements in limb power and equivalent improvements in strength . Observed differences between NIA and InVEST based upon baseline leg impairment status are informative for futures studies It is unclear whether strength training ( ST ) or power training ( PT ) is the more effective intervention at improving muscle strength and power and physical function in older adults . The authors compared the effects of lower extremity PT with those of ST on muscle strength and power in 45 older adults ( 74.8 + /- 5.7 yr ) with self-reported difficulty in common daily activities . Participants were r and omized to 1 of 3 treatment groups : PT , ST , or wait-list control . PT and ST trained 3 times/wk for 12 wk using knee-extension ( KE ) and leg-press ( LP ) machines at approximately 70 % of 1-repetition maximum ( 1RM ) . For PT , the concentric phase of the KE and LP was completed " as fast as possible , " whereas for ST the concentric phase was 2 - 3 s. Both PT and ST paused briefly at the midpoint of the movement and completed the eccentric phase of the movement in 2 - 3 s. PT and ST groups showed significant improvements in KE and LP 1RM compared with the control group . Maximum KE and LP power increased approximately twofold in PT compared with ST . At 12 wk , compared with control , maximum KE and LP power were significantly increased for the PT group but not for the ST group . In older adults with compromised function , PT leads to similar increases in strength and larger increases in power than ST BACKGROUND Age-related decline in muscle power may be an early indicator of balance deficits and fall risk , even in nonfrail adults . This study examined the dose-dependent effect of power training on balance performance in healthy older adults . METHODS One hundred twelve community-dwelling healthy older adults ( 69 + /- 6 years ) were r and omized to 8 - 12 weeks of power training at 20 % ( LOW ) , 50 % ( MED ) , or 80 % ( HIGH ) of maximal strength , or a nontraining control ( CON ) group . Participants trained twice weekly ( five exercises ; three sets of eight rapid concentric/slow eccentric repetitions ) using pneumatic resistance machines .  Balance , muscle performance ( strength , power , endurance , contraction velocity ) , and body composition were measured . RESULTS Power training significantly improved balance performance ( p = .006 ) in participants who underwent power training compared to controls . Low intensity power training produced the greatest improvement in balance performance ( p = .048 ) . Average contraction velocity at low load ( 40 % one repetition maximum [ 1RM ] ) at baseline independently predicted improvement in balance following training ( r = -.29 , p = .004 ) . CONCLUSIONS Power training improves balance , particularly using a low load , high velocity regimen , in older adults with initial lower muscle power and slower contraction . Further studies are warranted to define the mechanisms underlying this adaptation , as well as the optimum power training intensity for a range of physiological and clinical outcomes in older adults with varying levels of health status and functional independence This study investigated the effect of a 10-week power training ( PT ) program versus traditional resistance training ( TRT ) on functional performance , and muscular power and strength in older men . Twenty inactive volunteers ( 60–76 years old ) were r and omly assigned to a PT group ( three 8–10 repetition sets performed as fast a possible at 60 % of 1-RM ) or a TRT group ( three 8–10 repetition sets with 2–3 s contractions at 60 % of 1-RM ) . Both groups exercised 2 days/week with the same work output . Outcomes were measured with the Rikli and Jones functional fitness test and a bench and leg press test of maximal power and strength ( 1-RM ) . Significant differences between and within groups were analyzed using a two-way analysis of variance ( ANOVA ) . At 10 weeks there was a significantly ( P < 0.05 ) greater improvement in measures of functional performance in the PT group . Arm curling improved by 50 versus 3 % and a 30 s chair-st and improved by 43 versus 6 % in the PT and TRT groups , respectively . There was also a significantly greater improvement in muscular power ( P < 0.05 ) in the PT group . The bench press improved by 37 versus 13 % , and the leg press by 31 and 8 % in the PT and TRT groups , respectively . There was no significant difference between groups in improved muscular strength . It appears that in older men there may be a significantly greater improvement in functional performance and muscular power with PT versus low velocity resistance training BACKGROUND The performance of daily tasks , such as stair climbing or lifting an object , requires both muscle strength and power . Age-associated reductions in strength and power can affect an older adult 's ability to complete daily tasks such as stair climbing and lifting a child . METHODS The purpose s of this study were to determine whether power training was more efficacious than strength training for improving whole-body physical function in older adults and to examine the relationship between changes in anaerobic power and muscle strength and changes in physical function . Thirty-nine men and women ( mean age + /- SD = 72.5 + /- 6.3 years ) with below-average leg extensor power were r and omly assigned to control ( C , n = 15 ) , strength-training ( ST , n = 13 ) or power-training ( PT , n = 11 ) groups . The ST and PT groups met 3 days per week for 16 weeks ; the C group maintained usual activity and attended three lectures during the course of the study . Primary outcome measures included the Continuous Scale Physical Functional Performance test , maximal strength , and anaerobic power . RESULTS After baseline was controlled for , the Continuous Scale Physical Functional Performance test total score was significantly greater for the PT group than for the ST ( p = .033 ) and C ( p = .016 ) groups . Maximal strength was significantly greater for the ST group than for the C group ( p = .015 ) after the intervention . There was no significant difference between groups for peak anaerobic power . CONCLUSIONS Power training was more effective than strength training for improving physical function in community-dwelling older adults Sayers SP , Bean J , Cuoco A , LeBrasseur NK , Jette A , Fielding RA : Changes in function and disability after resistance training : Does velocity matter ? A pilot study . Am J Phys Med Rehabil 2003;82:605–613 . Objective To compare the effects of high- and low-velocity resistance training on functional performance and disability outcomes in physically limited older women . Design A total of 16 wk of high-velocity resistance training or traditional low-velocity resistance training consisting of knee extension and leg press exercises was performed three times per week by 30 women with self-reported disability to compare their effect on functional performance and disability . Tests of dynamic balance , stair-climb time , chair-rise time , and gait velocity were used to assess changes in functional performance . Changes in disability were assessed using the Medical Outcomes Study Short Form . Results Dynamic balance and stair-climb time improved 8 % and 10 % , respectively , with training . Self-reported disability , physical functioning , role physical , and mental health improved 11 , 9 , and 5 % with training , respectively . There were no significant differences between high- and low-velocity training groups . Conclusions High- and low-velocity training achieved similar improvements in functional performance and disability . Improvements in functional performance and disability were modest compared with robust increases in strength and power . Specific modes of training or behavioral strategies may be necessary to optimize improvements in these outcomes OBJECTIVES Peak power declines more precipitously than strength with advancing age and is a reliable measure of impairment and a strong predictor of functional performance . We tested the hypothesis that a high-velocity resistance-training program ( HI ) would increase muscle power more than a traditional low-velocity resistance-training program ( LO ) . DESIGN R and omized controlled trial . SETTING University-based human physiology laboratory . PARTICIPANTS Thirty women with self-reported dis-ability ( aged 73 + 1 , body mass index 30.1 + 1.1 kg/mn ) . INTERVENTION We conducted a r and omized trial comparing changes in skeletal muscle power and strength after 16 weeks of HI or LO . Training was performed three times per week , and subjects completed three sets ( 8 - 10 repetitions ) of leg press ( LP ) and knee extension ( KE ) exercises at 70 % of the one-repetition maximum ( IRM ) . MEASUREMENTS One-repetition maximum ( 1 RM ) and peak power for KE and LP . RESULTS LP and KE relative training force and total work were similar between groups ( P > .05 ) . However , HI generated significantly higher power during training sessions than LO for LP ( 3.7-fold greater , P < .001 ) and KE ( 2.1-fold greater , P < .001 ) . Although LP and KE 1RM muscle strength increased similarly in both groups asa result of the training ( P < .001 ) , LP peak power increased significantly more in HI than in LO ( 267 W vs 139 W , P < .001 ) . Furthermore , HI result ed in a significantly greater improvement in LP power at 40 % , 50 % , 60%,70 % , 80 % , and 90 % of the 1 RM than did LO ( P < .05 ) . CONCLUSIONS HI improved 1RM strength similarly and was more effective in improving peak power than was traditional LO in older women . Improvements in lower extremity peak power may exert a greater influence on age-associated reductions in physical functioning than other exercise interventions AIM Loss of muscle strength and balance are main characteristics of physical frailty in old age . Postural sway is associated with muscle contractile capacity and to the ability of rapidly correcting ankle joint changes . Thus , resistance training would be expected to improve not only strength but also postural balance . METHODS In this study , age-matched older individuals ( 69.9+/-1.3 years ) were r and omly assigned to flywheel ( n=12 ) , or weight-lifting ( n=12 ) groups , training the knee extensors thrice weekly for 12 weeks . The hypotheses were that owing to a larger eccentric loading of the knee extensors , flywheel training would result in ( a ) greater gains in quadriceps strength ; ( b ) greater improvements in balance performance compared with weight-lifting training . Isokinetic dynamometry , B-mode ultrasonography , electromyography , percutaneous muscle stimulation and magnetic resonance imaging were employed to acquire the parameters of interest . RESULTS Following training , knee extensors peak isokinetic power increased by 28 % ( P<0.01 ) in the flywheel group with no change in the weight-lifting group . Adaptations of the gastrocnemius muscle also occurred in both groups . The gastrocnemius characteristic with the highest response to training was tendon stiffness , with increases of 54 % and 136 % in the weight-lifting and flywheel groups , respectively ( P<0.01 ) . The larger increase in tendon stiffness in the flywheel group was associated with an improvement in postural balance ( P<0.01 ) . CONCLUSION Quadriceps flywheel loading not only produces a greater increase in power than weight training but its physiological benefits also transfer/overspill to the plantarflexor muscle-tendon unit result ing in a significantly improved balance . These findings support our initial hypotheses
target: power training is feasible for elderly persons and has a small advantage over strength training for functional outcomes .
background: OBJECTIVE to determine the effects of power training with high movement velocity compared with conventional resistance training with low movement velocity for older community-dwelling people .