Motor performance and motor learning as a function of age and fitness. Randomized clinical trial of therapeutic exercise in subacute stroke. Physical activity and functional limitations in older adults: a systematic review related to Canada's Physical Activity Guidelines Motor Training of Upper Extremity With Functional Electrical Stimulation in Early Stroke Rehabilitation Encoding a motor memory in the older adult by action observation Physical activity in prefrail older adults: confidence and satisfaction related to physical function. Portable upper extremity robotics is as efficacious as upper extremity rehabilitative therapy: a randomized controlled pilot trial A community-based upper-extremity group exercise program improves motor function and performance of functional activities in chronic stroke: a randomized controlled trial. Improving balance control and self-reported lower extremity function in community-dwelling older adults: a randomized control trial Upper extremity muscle volumes and functional strength after resistance training in older adults. Functional and Neuromotor Performance in Older Adults: Effect of 12 Wks of Aerobic Exercise Effects of three different low-intensity exercise interventions on physical performance, muscle CSA and activities of daily living: A randomized controlled trial Implicit Motor Sequence Learning and Working Memory Performance Changes Across the Adult Life Span Home-based, upper-arm exercise training for patients with chronic obstructive pulmonary disease. Multidimensional Motor Sequence Learning Is Impaired in Older But Not Younger or Middle-Aged Adults Psychological and cognitive outcomes of a randomized trial of exercise among patients with chronic obstructive pulmonary disease. Does training with traditionally presented and virtually simulated tasks elicit differing changes in object interaction kinematics in persons with upper extremity hemiparesis?
Past studies have shown that electroencephalographic alpha activity increases as people learn to perform a novel motor task . Additionally , it has been suggested that motor performance and learning decline as people age beyond 60 years , and it has been hypothesized that physical fitness may attenuate this decline through its impact on the cerebral environment . This study was design ed to replicate past research by assessing changes in alpha activity as a function of learning and to extend past research by examining differences in motor performance , motor learning , and alpha activity as a function of age and fitness . VO2max was assessed in 41 older ( ages 60 - 80 years ) and 42 younger ( ages 20 - 30 years ) participants . Participants were r and omly assigned to experimental or control conditions , which differed in the amount of practice received . Participants performed trials on the mirror star trace on both an acquisition and a retention day . Results indicated that younger participants performed better and had greater learning than older participants . Fitness was not found to impact either performance or learning . Participants in the experimental group improved more than those in the control group and maintained this difference at retention , which suggests that learning occurred . Associated with these improvements in performance capabilities was an increase in alpha power BACKGROUND AND PURPOSE Rehabilitation care after stroke is highly variable and increasingly shorter in duration . The effect of therapeutic exercise on impairments and functional limitations after stroke is not clear . The objective of this study was to determine whether a structured , progressive , physiologically based exercise program for subacute stroke produces gains greater than those attributable to spontaneous recovery and usual care . METHODS This r and omized , controlled , single-blind clinical trial was conducted in a metropolitan area and 17 participating healthcare institutions . We included persons with stroke who were living in the community . One hundred patients ( mean age , 70 years ; mean Orpington score , 3.4 ) consented and were r and omized from a screened sample of 582 . Ninety-two subjects completed the trial . Intervention was a structured , progressive , physiologically based , therapist-supervised , in-home program of thirty-six 90-minute sessions over 12 weeks targeting flexibility , strength , balance , endurance , and upper-extremity function . Main outcome measures were postintervention strength ( ankle and knee isometric peak torque , grip strength ) , upper- and lower-extremity motor control ( Fugl Meyer ) , balance ( Berg and functional reach ) , endurance ( peak aerobic capacity and exercise duration ) , upper-extremity function ( Wolf Motor Function Test ) , and mobility ( timed 10-m walk and 6-minute walk distance ) . RESULTS In the intention-to-treat multivariate analysis of variance testing the overall effect , the intervention produced greater gains than usual care ( Wilk 's lambda=0.64 , P=0.0056 ) . Both intervention and usual care groups improved in strength , balance , upper- and lower-extremity motor control , upper-extremity function , and gait velocity . Gains for the intervention group exceeded those in the usual care group in balance , endurance , peak aerobic capacity , and mobility . Upper-extremity gains exceeded those in the usual care group only in patients with higher baseline function . CONCLUSIONS This structured , progressive program of therapeutic exercise in persons who had completed acute rehabilitation services produced gains in endurance , balance , and mobility beyond those attributable to spontaneous recovery and usual care Background The purpose was to conduct systematic review s of the relationship between physical activity of healthy community-dwelling older ( > 65 years ) adults and outcomes of  functional limitations , disability , or loss of independence .  Methods Prospect i ve cohort studies with an outcome related to functional independence or to cognitive function  were search ed , as well as exercise training interventions that reported a functional outcome . Electronic data base search strategies were used to identify citations which were screened ( title and abstract ) for inclusion . Included articles were review ed to complete st and ardized data extraction tables , and assess study quality . An established system of assessing the level and grade of evidence for recommendations was employed . Results Sixty-six studies met inclusion criteria for the relationship between physical activity and functional independence , and 34 were included with a cognitive function outcome . Greater physical activity of an aerobic nature ( categorized by a variety of methods ) was associated with higher functional status ( expressed by a host of outcome measures ) in older age . For functional independence , moderate ( and high ) levels of physical activity appeared effective in conferring a reduced risk ( odds ratio ~0.5 ) of functional limitations or disability . Limitation in higher level performance outcomes was reduced ( odds ratio ~0.5 ) with vigorous ( or high ) activity with an apparent dose-response of moderate through to high activity . Exercise training interventions ( including aerobic and resistance ) of older adults showed improvement in physiological and functional measures , and suggestion of longer-term reduction in incidence of mobility disability . A relatively high level of physical activity was related to better cognitive function and reduced risk of developing dementia ; however , there were mixed results of the effects of exercise interventions on cognitive function indices . Conclusions There is a consistency of findings across studies and a range of outcome measures related to functional independence ; regular aerobic activity and short-term exercise programmes confer a reduced risk of functional limitations and disability in older age . Although a precise characterization of a minimal or effective physical activity dose to maintain functional independence is difficult , it appears moderate to higher levels of activity are effective and there may be a threshold of at least moderate activity for significant outcomes Background . Functional electrical stimulation ( FES ) allows active exercises in stroke patients with upper extremity paralysis . Objective . To investigate the effect of motor training with FES on motor recovery in acute and subacute stroke patients with severe to complete arm and /or h and paralysis . Methods . For this pilot study , 23 acute and subacute stroke patients were r and omly assigned to the intervention ( n = 12 ) and control group ( n = 11 ) . Distributed over 4 weeks , FES training replaced 12 conventional training sessions in the intervention group . An Extended Barthel Index ( EBI ) subscore assessed the performance of activities of daily living ( ADL ) . The Chedoke McMaster Stroke Assessment ( CMSA ) measured h and and arm function and shoulder pain . The Modified Ashworth Scale ( MAS ) assessed resistance to passive movement . Unblinded assessment s were performed prior to and following the end of the training period . Results . The EBI subscore and CMSA arm score improved significantly in both groups . The CMSA h and function improved significantly in the FES group . Resistance to passive movement of finger and wrist flexors increased significantly in the FES group . Shoulder pain did not change significantly . None of the outcome measures , however , demonstrated significant gain differences between the groups . Conclusions . We did not find clear evidence for superiority or inferiority of FES . Our findings , and those of similar trials , suggest that the number of sessions should be at least doubled to test for superiority of FES in these highly impaired patients and approximately 50 participants would have to be assigned to each therapeutic intervention to find significant differences The ability of motor training to encode a motor memory is reduced in older adults . Here , we tested the hypothesis that training-dependent memory encoding , an issue of relevance in neurorehabilitation , is enhanced in elder individuals by action observation which alone can contribute to learning processes . A group of 11 healthy older adults participated in this study , which consisted of three r and omized counterbalanced sessions on different days testing the effects of motor training ( MT ) alone , action observation ( AO ) alone , and a combination of both ( MT + AO ) on motor memory encoding . The combination of MT + AO formed a motor memory in the primary motor cortex and differentially modulated motor cortical excitability in muscles that were agonist and antagonist with respect to the training task , but MT or AO alone did not . These results suggest that action observation can enhance the effects of motor training on memory encoding protocol s in the older adult , possibly through Hebbian modulation of intracortical excitatory mechanisms We examined the hypothesis that physical activity will have favorable effects on measures of self-efficacy for a 400-m walk and satisfaction with physical functioning in older adults 70 + years of age who have deficits in mobility . We r and omized a total of 412 adults aged 70 - 89 years at elevated risk for mobility disability to either a physical activity or a successful aging educational control intervention for 12 months . Participants in the physical activity intervention had more favorable changes in both outcomes as a result of treatment than those in the successful aging intervention . Gender , age , and scores on a short physical performance battery did not moderate these effects . Physical activity is an effective means of intervening on self-efficacy and satisfaction with physical function in older adults with impaired lower extremity functioning . This is an important finding in light of the importance of these process variables in behavior change and quality of life Objective : To compare the efficacy of a repetitive task-specific practice regimen integrating a portable , electromyography-controlled brace called the ‘ Myomo ’ versus usual care repetitive task-specific practice in subjects with chronic , moderate upper extremity impairment . Subjects : Sixteen subjects ( 7 males ; mean age 57.0 ± 11.02 years ; mean time post stroke 75.0 ± 87.63 months ; 5 left-sided strokes ) exhibiting chronic , stable , moderate upper extremity impairment . Interventions : Subjects were administered repetitive task-specific practice in which they participated in valued , functional tasks using their paretic upper extremities . Both groups were supervised by a therapist and were administered therapy targeting their paretic upper extremities that was 30 minutes in duration , occurring 3 days/week for eight weeks . One group participated in repetitive task-specific practice entirely while wearing the portable robotic , while the other performed the same activity regimen manually . Main outcome measures : The upper extremity Fugl-Meyer , Canadian Occupational Performance Measure and Stroke Impact Scale were administered on two occasions before intervention and once after intervention . Results : After intervention , groups exhibited nearly identical Fugl-Meyer score increases of ≈2.1 points ; the group using robotics exhibited larger score changes on all but one of the Canadian Occupational Performance Measure and Stroke Impact Scale subscales , including a 12.5-point increase on the Stroke Impact Scale recovery subscale . Conclusions : Findings suggest that therapist-supervised repetitive task-specific practice integrating robotics is as efficacious as manual practice in subjects with moderate upper extremity impairment OBJECTIVE To assess the effects of a community-based exercise program on motor recovery and functional abilities of the paretic upper extremity in persons with chronic stroke . DESIGN R and omized controlled trial . SETTING Rehabilitation research laboratory and a community hall . PARTICIPANTS A sample of 63 people ( > or = 50y ) with chronic deficits result ing from stroke ( onset > or = 1y ) . INTERVENTIONS The arm group underwent an exercise program design ed to improve upper-extremity function ( 1h/session , 3 sessions/wk for 19wk ) . The leg group underwent a lower-extremity exercise program . MAIN OUTCOME MEASURES The Wolf Motor Function Test ( WMFT ) , Fugl-Meyer Assessment ( FMA ) , h and -held dynamometry ( grip strength ) , and the Motor Activity Log . RESULTS Multivariate analysis showed a significant group by time interaction ( Wilks lambda=.726 , P=.017 ) , indicating that overall , the arm group had significantly more improvement than the leg group . Post hoc analysis demonstrated that gains in WMFT ( functional ability ) ( P=.001 ) and FMA ( P=.001 ) scores were significantly higher in the arm group . The amount of improvement was comparable to other novel treatment approaches such as constraint-induced movement therapy or robot-aided exercise training previously reported in chronic stroke . Participants with moderate arm impairment benefited more from the program . CONCLUSIONS The pilot study showed that a community-based exercise program can improve upper-extremity function in persons with chronic stroke . This outcome justifies a larger clinical trial to further assess efficacy and cost effectiveness Objectives : To evaluate the effect of a group-based functional and specific balance training programme that included dual-task exercises on balance function  in healthy older adults . Design : A single-blind r and omized controlled trial . Setting : General community . Participants : Sixty-six community-dwelling older adults ( age 77.0 ± 6.5 years ) , without functional balance impairment were recruited and allocated at r and om to an intervention group ( n = 33 ) or a reference group ( n = 33 ) . Intervention : The intervention group received 24 training sessions over three months that included perturbation as well as dual-task exercises . The reference group received no intervention . Outcome measures : The voluntary step execution times during single- and dual-task conditions , stabilogram-diffusion analysis in upright st and ing , and self-reported physical function ; all were measured assessed at baseline and at the end of intervention . The intervention group was retested after six months . Results : Compared with the reference group , participation in group-based functional and specific balance training led to faster voluntary step execution times under single-task ( P = 0.02 ; effect size ( ES ) = 0.34 ) and dual-task ( P = 0.036 ; ES = 0.55 ) conditions ; lower transition displacement and shorter transition time of the stabilogram-diffusion analysis under eyes-closed conditions ( P = 0.007 , ES = 0.30 and P = 0.08 , ES = 0.44 , respectively ) ; and improved self-reported lower extremity function ( P = 0.006 , ES = 0.37 ) . Effects were lost at six-month follow-up . Conclusions : Functional and specific balance training can improve voluntary stepping and balance control in healthy older non-fallers , parameters previously found to be related to increased risk of falls and injury in older adults Aging leads to a decline in strength and an associated loss of independence . The authors examined changes in muscle volume , maximum isometric joint moment , functional strength , and 1-repetition maximum ( 1RM ) after resistance training ( RT ) in the upper extremity of older adults . They evaluated isometric joint moment and muscle volume as predictors of functional strength . Sixteen healthy older adults ( average age 75 ± 4.3 yr ) were r and omized  to a 6-wk upper extremity RT program or control group . The RT group increased 1RM significantly ( p < .01 for all exercises ) . Compared with controls , r and omization to RT led to greater functional pulling strength ( p = .003 ) , isometric shoulder-adduction moment ( p = .041 ) , elbow-flexor volume ( p = .017 ) , and shoulder-adductor volume ( p = .009 ) . Shoulder-muscle volumes and isometric moments were good predictors of functional strength . The authors conclude that shoulder strength is an important factor for performing functional reaching and pulling tasks and a key target for upper extremity RT interventions Kalapotharakos VI , Michalopoulos M , Strimpakos N , Diamantopoulos K , Tokmakidis SP : Functional and neuromotor performance in older adults : Effect of 12 wks of aerobic exercise . Am J Phys Med Rehabil 2006;85:61–67 . Objective : There is little information regarding the effect of aerobic exercise on physical and neuromotor performance in older adults . The aim of this r and omized , controlled trial was to determine the effects of a 12-wk aerobic exercise program on functional and neuromotor performance in inactive healthy older adults . Design : A total of 22 inactive healthy older adults , aged 60–75 yrs , voluntarily participated in the study and were r and omly assigned to a progressively increased high-intensity aerobic exercise group ( n = 12 ) or to a control group ( n = 10 ) . The aerobic exercise group exercised three times per week for 12 wks on nonconsecutive days . Both groups were evaluated before and after the exercise period in the one-repetition maximum of knee extensors and flexors , 6-min walk distance , chair-rising time , and whole-body reaction time . Results : Multivariate analysis of variance repeated measures ( 2 × 2 ) revealed significant ( P < 0.05 ) time by group interaction for one-repetition maximum knee extension and flexion strength , 6-min walk distance , chair-rising time , and whole-body reaction time . For the aerobic exercise group , the following variables improved significantly ( P < 0.05 ) after the exercise period : the one-repetition maximum knee extensors ( 12 % ) and flexors ( 19 % ) muscle strength , 6-min walk distance ( 17 % ) , chair-rising time ( 8 % ) , and whole-body reaction time ( 20 % ) . No significant differences were observed in the control group . Conclusions : The results of the present study show that short-term progressively increased high-intensity aerobic exercise improved the physical and neuromotor performance in inactive healthy older adults . These findings suggest that the participation in a progressively increased high-intensity aerobic exercise program may improve mobility and ability to carry out activities of daily living in older adults OBJECTIVES To evaluate the short-term effects of three different resistance training programs , conducted at low intensity , on physical performance , muscle cross-sectional area ( CSA ) and the capacity to perform daily tasks in older adults living in a geriatric nursing home . DESIGN R and omized controlled trial , with a 4-month intervention period . SETTING A geriatric nursing home in Valencia , Spain . PARTICIPANTS Eighty-nine adults aged 75 to 96 who were independent in their daily activities . INTERVENTION After a baseline assessment , the participants were r and omly assigned to the control group or one of the three intervention groups : volitional contraction ( VC ; n=22 ) , neuromuscular electrical stimulation ( NMES ; n=22 ) , or neuromuscular electrical stimulation superimposed onto voluntary contractions ( NMES+ ; n=22 ) . The intervention focused on knee extension exercises and its intensity was set at 40 % of one-repetition maximum ( 1RM ) . MEASUREMENTS The primary outcome measure was mobility . Secondary outcomes were rectus femoris CSA , balance , aerobic endurance , upper-body strength and the capacity to perform daily tasks . All data were collected at baseline and after the 4-month intervention period . RESULTS The two-way ANOVA analysis showed a significant group × time interaction effect for the mobility ( P=.022 ) , rectus femoris CSA ( P=.001 ) , and the capacity to perform daily tasks ( P=.05 ) . The within-group analysis found a more prominent effect in the NMES+ group . Significant improvements were seen in rectus femoris CSA and the capacity to perform daily tasks in all intervention groups . Mobility only improved in the NMES+ group ( P=.026 ) . CONCLUSION From a short-term perspective , NMES+ exercise training , performed at low intensity , can improve physical performance , muscle CSA , and the capacity to perform daily activities , and to partially mitigate age-related consequences in older adults Although implicit motor sequence learning is rather well understood in young adults , effects of aging on this kind of learning are controversial . There is first evidence that working memory ( WM ) might play a role in implicit motor sequence learning in young adults as well as in adults above the age of 65 . However , the knowledge about the development of these processes across the adult life span is rather limited . As the average age of our population continues to rise , a better underst and ing of age-related changes in motor sequence learning and potentially mediating cognitive processes takes on increasing significance . Therefore , we investigated aging effects on implicit motor sequence learning and WM . Sixty adults ( 18–71 years ) completed verbal and visuospatial n-back tasks and were trained on a serial reaction time task ( SRTT ) . R and omly varying trials served as control condition . To further assess consolidation indicated by off-line improvement and reduced susceptibility to interference , reaction times ( RTs ) were determined 1 h after initial learning . Young and older but not middle-aged adults showed motor sequence learning . Nine out of 20 older adults ( compared to one young/one middle-aged ) exhibited some evidence of sequence awareness . After 1 h , young and middle-aged adults showed off-line improvement . However , RT facilitation was not specific to sequence trials . Importantly , susceptibility to interference was reduced in young and older adults indicating the occurrence of consolidation . Although WM performance declined in older participants when load was high , it was not significantly related to sequence learning . The data reveal a decline in motor sequence learning in middle-aged but not in older adults . The use of explicit learning strategies in older adults might account for the latter result Prior studies demonstrate the ability of upper extremity training to increase arm strength and endurance when incorporated into a pulmonary rehabilitation program . However , patients with severe chronic obstructive pulmonary disease ( COPD ) may have transportation or mobility problems that make it difficult to travel to a rehabilitation site to obtain this training . This pilot study was design ed to determine whether a home-based , upper-arm exercise program could increase arm strength and endurance , and decrease perceptions of breathlessness and fatigue during five activities of daily living . Twenty patients with severe COPD ( FEV1 0.80 + /- 0.42 ) were r and omized to an experimental ( n = 10 ) or control group ( n = 10 ) . The experimental-group training included three upper arm exercises five times a week for 8 weeks , with training level incremented during weekly home visits . Control-group subjects were contacted weekly to equalize attention from health care providers . During the upper-extremity endurance test for number of rings moved , no significant differences between groups were seen for interaction or treatment . However , there was a significant interaction between treatment and time for perceived fatigue ( p = 0.0012 ) , with the experimental group perceiving less fatigue during upper arm work than did the control group . No change was seen in perceived breathlessness . Findings of this study suggest that a home-based , upper-arm exercise program can reduce perceptions of fatigue for patients with severe COPD during activities involving upper arm work . Testing in a larger sample is indicated to determine whether this training can also improve ability to perform unsupported arm work Background and Purpose : The purpose of this study was to identify which characteristics of a multidimensional sequence containing motor , spatial , and temporal elements would be most salient for motor sequence learning and whether age might differentially affect this learning . Subjects : Younger ( n=11 , mean age=26.0 years ) , middle-aged ( n=13 , mean age=50.7 years ) , and older ( n=11 , mean age=77.5 years ) adults who were neurologically intact participated in the study . Methods : Participants practice d a sequencing task with repeated motor , spatial , and temporal dimensions for 2 days ; on a separate third day , participants completed retention and interference tests design ed to assess sequence learning and which elements of the sequence were learned . The mean median response time for each block of responses was used to assess motor sequence learning . Results : Younger and middle-aged adults demonstrated sequence-specific motor learning at retention testing via faster response times for repeated sequences than r and om sequences ; both of these groups showed interference for the motor dimension . In contrast , older adults demonstrated nonspecific learning ( ie , similar improvements in response time for both r and om and repeated sequences ) . These findings were shown by a lack of difference between r and om and repeated sequence performance in the older adult group both at retention testing and during interference tests . Conclusion and Discussion : Our data suggest that , when younger and middle-aged adults practice sequences containing multiple dimensions of movement , the motor element is most important for motor learning . The absence of sequence-specific change demonstrated by an older adult group that was healthy suggests an age-related impairment in motor learning that may have profound implication s for rehabilitation Exercise rehabilitation is recommended increasingly for patients with chronic obstructive pulmonary disease ( COPD ) . This study examined the effect of exercise and education on 79 older adults ( M age = 66.6 + /- 6.5 years ; 53 % female ) with COPD , r and omly assigned to 10 weeks of ( a ) exercise , education , and stress management ( EXESM ; n = 29 ) ; ( b ) education and stress management ( ESM ; n = 25 ) ; or ( c ) waiting list ( WL ; n = 25 ) . EXESM included 37 sessions of exercise , 16 educational lectures , and 10 weekly stress management classes . ESM included only the 16 lectures and 10 stress management classes . Before and after the intervention , assessment s were conducted of physiological functioning ( pulmonary function , exercise endurance ) , psychological well-being ( depression , anxiety , quality of life ) , and cognitive functioning ( attention , motor speed , mental efficiency , verbal processing ) . Repeated measures multivariate analysis of variance indicated that EXESM participants experienced changes not observed among ESM and WL participants , including improved endurance , reduced anxiety , and improved cognitive performance ( verbal fluency ) Abstract Objective : To contrast changes in clinical and kinematic measures of upper extremity movement in response to virtually simulated and traditionally presented rehabilitation interventions in persons with upper extremity hemiparesis due to chronic stroke . Design : Non-r and omized controlled trial . Setting : Ambulatory research facility . Participants : Subjects were a volunteer sample of twenty one community-dwelling adults ( mean age : 51 ± 12 years ) with residual hemiparesis due to stroke more than 6 months before enrollment ( mean : 74 ± 48 months ) , recruited at support groups . Partial range , against gravity shoulder movement and at least 10 ° of active finger extension were required for inclusion . All subjects completed the study without adverse events . Interventions : A 2 weeks , 24-hour program of robotic/virtually simulated , arm and finger rehabilitation activities was compared to the same dose of traditionally presented arm and finger activities . Results : Subjects in both groups demonstrated statistically significant improvements in the ability to interact with real-world objects as measured by the Wolf Motor Function Test ( P = 0.01 ) . The robotic/virtually simulated activity ( VR ) group but not the traditional , repetitive task practice ( RTP ) group demonstrated significant improvements in peak reaching velocity ( P = 0.03 ) and finger extension excursion ( P = 0.03 ) . Both groups also demonstrated similar improvements in kinematic measures of reaching and grasping performance such as increased shoulder and elbow excursion along with decreased trunk excursion . Conclusions : Kinematic measurements identified differing adaptations to training that clinical measurements did not . These adaptations were targeted in the design of four of the six simulations performed by the simulated activity group . Finer grained measures may be necessary to accurately depict the relative benefits of dose matched motor interventions
Results concerning the association of chronic physical activity and motor performance are mixed and seem to be influenced by the study design , kind of exercise , motor task , and exercise intensity .
Regarding motor learning , a high physical activity or cardiovascular fitness level seems to boost the initial phase of motor learning ; results differ with respect to motor retention .
Overall , ( motor-coordinative ) intervention studies seem to be more promising than cross-sectional studies
Upper extremity motor performance declines with increasing age .
However , older adults need to maintain , learn new and relearn known motor tasks .
Research with young adults indicated that regular and acute physical activity might facilitate motor performance and motor learning processes .
Therefore , this review aim ed to examine the association between chronic physical activity and acute bouts of exercise on motor performance and motor learning in upper extremity motor tasks in older adults .