Reaction time unchanged in older women following aerobic training

Two Months of Using Global Recommendations for Physical Activity Had No Impact on Cognitive or Motor Functions in Overweight and Obese Middle-Aged Women

BACKGROUND

The effect of globally recommended levels of physical activity on cognition and motor behavior is not completely understood. Therefore, the main aim of this study was to assess the effect of 300 minutes per week of moderate-intensity aerobic exercise on cognitive and motor performance among overweight and obese working-age women.

METHODS

Overweight and obese participants aged 38-56 years were randomized to either a control or an experimental group performing aerobic exercise at 50% to 60% of the peak oxygen consumption for a 2-month period. Changes in aerobic fitness, cardiac autonomic function, brain-derived neurotropic factor levels, and cognitive and motor performance were assessed.

RESULTS

Although aerobic exercise reduced body weight (P < .05) and improved peak oxygen consumption (P < .05), the brain-derived neurotropic factor levels and cognitive and motor performance remained unchanged. Heart rate and blood pressure decreased (P < .05), whereas heart rate variability indices were not affected. No significant correlations between changes in heart rate variability indices and cognition were observed.

CONCLUSIONS

Two months of moderate-intensity aerobic exercise decreased sympathetic activity and improved cardiovascular fitness but had no impact on cognition or motor control among these middle-aged, overweight, and obese women.

Multifactorial exercise and dance-based interventions are effective in reducing falls risk in community-dwelling older adults: A comparison study

BACKGROUND

Falls and injuries related to falls in older adults are a significant health care issue that affects the elderly population. Research suggests that exercise interventions can be effective in improving falls risk factors.

RESEARCH QUESTION

Are there differences in falls risk reduction between two exercise interventions (The Lebed Method - TLM and Stay Active and Independent for Life - SAIL) for community-dwelling older adults?

METHODS

A quasi-experimental pre- and post-test design was used for this study. One hundred and sixty-three older individuals aged between 60-79 years of age participated in the study. Assessments of falls risk (using the physiological profile assessment), simple reaction time, bilateral knee extension strength, proprioception, balance, visual acuity, and mobility (using timed-up-and-go, TUG) were performed. Analysis of covariance was conducted to compare the differences between the two interventions. Pre-intervention assessments were used as the covariate.

RESULTS

SAIL participants' falls risk were reduced more than TLM. Reaction and TUG times were faster for SAIL participants. However, those individuals who participated in TLM had greater knee extension strength for both legs compared to SAIL participants.

SIGNIFICANCE

Overall, both interventions were effective in reducing falls risk for older adults. The greater number of improved falls risk factors attained with the SAIL program suggests that multifactorial interventions may be more effective at reducing falls risk. However, since TLM also showed better improved strength, both dance-based and multifactorial interventions can be effective at reducing falls risk factors for older adults.

Impact of exercise training on physical and cognitive function among older adults: a systematic review and meta-analysis

Exercise plays a key role in healthy aging by promoting both physical and cognitive function. Physical function and cognitive function appear to be interrelated and may share common mechanisms. Thus, exercise-induced improvements in physical function and cognitive function may co-occur and be associated with each other. However, no systematic review has specifically assessed and compared the effects of exercise on both physical function and cognitive function in older adults, and the association between changes in both outcomes after exercise training. Thus, we conducted a systematic review and meta-analysis (N = 48 studies) among older adults (60+ years). These data suggest exercise training has a significant benefit for both physical function (g = 0.39; p < 0.001) and cognitive function (g = 0.24; p < 0.001). At the study level, there was a positive correlation between the size of the exercise-induced effect on physical function and on cognitive function (b = 0.41; p = 0.002). Our results indicate exercise improves both physical and cognitive function, reiterating the notion that exercise is a panacea for aging well.

Aerobic exercise to improve cognitive function in older people without known cognitive impairment

BACKGROUND

There is increasing evidence that physical activity supports healthy ageing. Exercise is helpful for cardiovascular, respiratory and musculoskeletal systems, among others. Aerobic activity, in particular, improves cardiovascular fitness and, based on recently reported findings, may also have beneficial effects on cognition among older people.

OBJECTIVES

To assess the effect of aerobic physical activity, aimed at improving cardiorespiratory fitness, on cognitive function in older people without known cognitive impairment.

SEARCH METHODS

We searched ALOIS - the Cochrane Dementia and Cognitive Improvement Group's Specialized Register, the Cochrane Controlled Trials Register (CENTRAL) (all years to Issue 2 of 4, 2013), MEDLINE (Ovid SP 1946 to August 2013), EMBASE (Ovid SP 1974 to August 2013), PEDro, SPORTDiscus, Web of Science, PsycINFO (Ovid SP 1806 to August 2013), CINAHL (all dates to August 2013), LILACS (all dates to August 2013), World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (http://apps.who.int/trialsearch), ClinicalTrials.gov (https://clinicaltrials.gov) and Dissertation Abstracts International (DAI) up to 24 August 2013, with no language restrictions.

SELECTION CRITERIA

We included all published randomised controlled trials (RCTs) comparing the effect on cognitive function of aerobic physical activity programmes with any other active intervention, or no intervention, in cognitively healthy participants aged over 55 years.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted the data from included trials. We grouped cognitive outcome measures into eleven categories covering attention, memory, perception, executive functions, cognitive inhibition, cognitive speed and motor function. We used the mean difference (or standardised mean difference) between groups as the measure of the treatment effect and synthesised data using a random-effects model. We conducted separate analyses to compare aerobic exercise interventions with no intervention and with other exercise, social or cognitive interventions. Also, we performed analyses including only trials in which an increase in the cardiovascular fitness of participants had been demonstrated.

MAIN RESULTS

Twelve trials including 754 participants met our inclusion criteria. Trials were from eight to 26 weeks in duration.We judged all trials to be at moderate or high risk of bias in at least some domains. Reporting of some risk of bias domains was poor.Our analyses comparing aerobic exercise to any active intervention showed no evidence of benefit from aerobic exercise in any cognitive domain. This was also true of our analyses comparing aerobic exercise to no intervention. Analysing only the subgroup of trials in which cardiorespiratory fitness improved in the aerobic exercise group showed that this improvement did not coincide with improvements in any cognitive domains assessed. Our subgroup analyses of aerobic exercise versus flexibility or balance interventions also showed no benefit of aerobic exercise in any cognitive domain.Dropout rates did not differ between aerobic exercise and control groups. No trial reported on adverse effects.Overall none of our analyses showed a cognitive benefit from aerobic exercise even when the intervention was shown to lead to improved cardiorespiratory fitness.

AUTHORS' CONCLUSIONS

We found no evidence in the available data from RCTs that aerobic physical activities, including those which successfully improve cardiorespiratory fitness, have any cognitive benefit in cognitively healthy older adults. Larger studies examining possible moderators are needed to confirm whether or not aerobic training improves cognition.

Dose-response relationship of cardiorespiratory fitness adaptation to controlled endurance training in sedentary older adults

BACKGROUND

The purpose of this investigation was to identify a quantitative dose-response relationship for enhancing maximal oxygen consumption (VO2max) in healthy sedentary older adults after controlled endurance training.

METHODS AND RESULTS

This meta-analysis of controlled clinical trials included 1257 exercisers and 845 controls with a mean age of 67.45 ± 5.25 years. Effect sizes were calculated for training-induced VO2max changes. Different training regimens were analyzed and compared. The weighted net change of the mean VO2max values showed a significant increase of 3.78 ml/kg per min (95% confidence interval = 3.29 to 4.27; p < 0.0001) in response to aerobic training. Interstudy differences in VO2max changes were significantly related to exercise intensity, and explained approximately 11% of the variance of the VO2max responses. VO2max improved significantly at 35%-50% heart rate reserve (HRR) and continued improving at a greater rate with increasing "dose". The largest VO2max-improvement adaptation was achieved with a mean intensity of 66%-73% HRR. The magnitudes of the VO2max adaptation are identical to exercise at 57%-65% HRR and at 75%-80% HRR. Higher intensity doses more than 75-80% HRR did not lead to greater enhancement of VO2max improvements but, conversely, resulted in large declines.

CONCLUSIONS

Our data provide quantitative insight into the magnitude of VO2max alterations as affected by exercise intensity, duration, frequency, and program length. The shapes of the dose-response curves are not simply linear, but with many similar trends and noteworthy characteristics. Aerobic training at a mean intensity of 66%-73% HRR with 40-50 min per session for 3-4 day/week for 30-40 weeks appears to be effective and optimal for maximum cardiorespiratory benefits in healthy sedentary older adults.

Exercise fails to improve neurocognition in depressed middle-aged and older adults

PURPOSE

Although cross-sectional studies have demonstrated an association between higher levels of aerobic fitness and improved neurocognitive function, there have been relatively few interventional studies investigating this relationship, and results have been inconsistent. We assessed the effects of aerobic exercise on neurocognitive function in a randomized controlled trial of patients with major depressive disorder (MDD).

METHODS

Two-hundred and two sedentary men (n = 49) and women (n = 153), aged 40 yr and over and who met diagnostic criteria for MDD, were randomly assigned to the following: a) supervised exercise, b) home-based exercise, c) sertraline, or d) placebo pill. Before and after 4 months of treatment, participants completed measures of: Executive Function (Trail Making Test B-A difference score, Stroop Color-Word, Ruff 2 & 7 Test, Digit Symbol), Verbal Memory (Logical Memory, Verbal Paired Associates), and Verbal Fluency/Working Memory (Animal Naming, Controlled Oral Word Association Test, Digit Span). Multivariate analyses of covariance were performed to test the effects of treatment on posttreatment neuropsychological test scores, with baseline neuropsychological test scores, age, education, and change in depression scores entered as covariates.

RESULTS

The performance of exercise participants was no better than participants receiving placebo across all neuropsychological tests. Exercise participants performed better than participants receiving sertraline on tests of executive function but not on tests of verbal memory or verbal fluency/working memory.

CONCLUSIONS

We found little evidence to support the benefits of an aerobic exercise intervention on neurocognitive performance in patients with MDD.

Aerobic exercise and neurocognitive performance: a meta-analytic review of randomized controlled trials

OBJECTIVES

To assess the effects of aerobic exercise training on neurocognitive performance. Although the effects of exercise on neurocognition have been the subject of several previous reviews and meta-analyses, they have been hampered by methodological shortcomings and are now outdated as a result of the recent publication of several large-scale, randomized, controlled trials (RCTs).

METHODS

We conducted a systematic literature review of RCTs examining the association between aerobic exercise training on neurocognitive performance between January 1966 and July 2009. Suitable studies were selected for inclusion according to the following criteria: randomized treatment allocation; mean age > or =18 years of age; duration of treatment >1 month; incorporated aerobic exercise components; supervised exercise training; the presence of a nonaerobic-exercise control group; and sufficient information to derive effect size data.

RESULTS

Twenty-nine studies met inclusion criteria and were included in our analyses, representing data from 2049 participants and 234 effect sizes. Individuals randomly assigned to receive aerobic exercise training demonstrated modest improvements in attention and processing speed (g = 0.158; 95% confidence interval [CI]; 0.055-0.260; p = .003), executive function (g = 0.123; 95% CI, 0.021-0.225; p = .018), and memory (g = 0.128; 95% CI, 0.015-0.241; p = .026).

CONCLUSIONS

Aerobic exercise training is associated with modest improvements in attention and processing speed, executive function, and memory, although the effects of exercise on working memory are less consistent. Rigorous RCTs are needed with larger samples, appropriate controls, and longer follow-up periods.

Effects of age, task complexity, and exercise on reaction time of women during ambulation tasks

PURPOSE

Reaction time (RT) is defined as the time lapse between the onset of a stimulus and the initiation of a response. The purpose of Study 1 was to compare RTs of young and elderly women during ambulation. The purpose of Study 2 was to investigate the effects of regular exercise on RTs of elderly women during ambulation tasks.

METHODS

Reaction times were measured using a portable computer, 2 transistor radios, and a radio interface box. The computer generated an auditory signal to which participants reacted by pushing a hand-held switch. Reaction times were compared in Study 1 between 17 healthy elderly women and 13 university students and in Study 2 between 15 exercising and 16 non-exercising elderly women. Testing of each participant occurred during sitting, walking on tile, and walking on foam padded carpet.

RESULTS

The results of Study 1 revealed differences in RT between the 2 groups and between the sitting and the 2 walking conditions, but no interaction between group and task complexity. The results of Study 2 revealed differences among all conditions, but not between groups.

CONCLUSIONS

The surprising result of Study 1 was that the elderly were not compromised to a greater extent than the young by increased task complexity. This suggests less age related RT decline during familiar activities. Results of Study 2 showed that level of exercise did not differentiate elderly participants' performance on RT. This may be because the active lifestyle of both groups of participants was more important in maintaining RT than a formal exercise program.

Physical activity and enhanced fitness to improve cognitive function in older people without known cognitive impairment

BACKGROUND

Physical activity is beneficial for healthy ageing. It may also help maintain good cognitive function in older age. Aerobic activity improves cardiovascular fitness, but it is not known whether this sort of fitness is necessary for improved cognitive function. Studies in which activity, fitness and cognition are reported in the same individuals could help to resolve this question.

OBJECTIVES

To assess the effectiveness of physical activity, aimed at improving cardiorespiratory fitness, on cognitive function in older people without known cognitive impairment.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, PEDro, SPORTDiscus, PsycINFO, CINAHL, Cochrane Controlled Trials Register (CENTRAL), Dissertation abstracts international and ongoing trials registers on 15 December 2005 with no language restrictions.

SELECTION CRITERIA

All published randomised controlled trials comparing aerobic physical activity programmes with any other intervention or no intervention with participants older than 55 years of age were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Eleven RCTs fulfilling the inclusion criteria are included in this review. Two reviewers independently extracted the data from these included studies.

MAIN RESULTS

Eight out of 11 studies reported that aerobic exercise interventions resulted in increased cardiorespiratory fitness of the intervention group (an improvement on the maximum oxygen uptake test which is considered to be the single best indicator of the cardiorespiratory system) of approximately 14% and this improvement coincided with improvements in cognitive capacity. The largest effects on cognitive function were found on motor function and auditory attention (effect sizes of 1.17 and 0.50 respectively). Moderate effects were observed for cognitive speed (speed at which information is processed; effect size 0.26) and visual attention (effect size 0.26).

AUTHORS' CONCLUSIONS

There is evidence that aerobic physical activities which improve cardiorespiratory fitness are beneficial for cognitive function in healthy older adults, with effects observed for motor function, cognitive speed, auditory and visual attention. However, the majority of comparisons yielded no significant results. The data are insufficient to show that the improvements in cognitive function which can be attributed to physical exercise are due to improvements in cardiovascular fitness, although the temporal association suggests that this might be the case. Larger studies are still required to confirm whether the aerobic training component is necessary, or whether the same can be achieved with any type of physical exercise. At the same time, it would be informative to understand why some cognitive functions seem to improve with (aerobic) physical exercise while other functions seem to be insensitive to physical exercise. Clinicians and scientists in the field of neuropsychology should seek mutual agreement on a smaller battery of cognitive tests to use, in order to render research on cognition clinically relevant and transparent and heighten the reproducibility of results for future research.

Physical activity and enhanced fitness to improve cognitive function in older people without known cognitive impairment

BACKGROUND

Physical activity is beneficial for healthy ageing. It may also help maintain good cognitive function in older age. Aerobic activity improves cardiovascular fitness, but it is not known whether this sort of fitness is necessary for improved cognitive function. Studies in which activity, fitness and cognition are reported in the same individuals could help to resolve this question.

OBJECTIVES

To assess the effectiveness of physical activity, aimed at improving cardiorespiratory fitness, on cognitive function in older people without known cognitive impairment.

SEARCH STRATEGY

We searched MEDLINE, EMBASE, PEDro, SPORTDiscus, PsycINFO, CINAHL, Cochrane Controlled Trials Register (CENTRAL), Dissertation abstracts international and ongoing trials registers on 15 December 2005 with no language restrictions.

SELECTION CRITERIA

All published randomised controlled trials comparing aerobic physical activity programmes with any other intervention or no intervention with participants older than 55 years of age were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

Eleven RCTs fulfilling the inclusion criteria are included in this review. Two reviewers independently extracted the data from these included studies.

MAIN RESULTS

Eight out of 11 studies reported that aerobic exercise interventions resulted in increased cardiorespiratory fitness of the intervention group (an improvement on the maximum oxygen uptake test which is considered to be the single best indicator of the cardiorespiratory system) of approximately 14% and this improvement coincided with improvements in cognitive capacity. The largest effects on cognitive function were found on motor function, auditory attention and delayed memory functions (effect sizes of 1.17, 0.52 and 0.50 respectively). However, the results for delayed memory functions should be interpreted with care since they are based on a single study. Moderate effects were observed for cognitive speed (speed at which information is processed; effect size 0.26) and visual attention (effect size 0.26).

AUTHORS' CONCLUSIONS

There is evidence that aerobic physical activities which improve cardiorespiratory fitness are beneficial for cognitive function in healthy older adults, with effects observed for motor function, cognitive speed, delayed memory functions and auditory and visual attention. However, the majority of comparisons yielded no significant results. The data are insufficient to show that the improvements in cognitive function which can be attributed to physical exercise are due to improvements in cardiovascular fitness, although the temporal association suggests that this might be the case. Larger studies are still required to confirm whether the aerobic training component is necessary, or whether the same can be achieved with any type of physical exercise. At the same time, it would be informative to understand why some cognitive functions seem to improve with (aerobic) physical exercise while other functions seem to be insensitive to physical exercise. Clinicians and scientists in the field of neuropsychology should seek mutual agreement on a smaller battery of cognitive tests to use, in order to render research on cognition clinically relevant and transparent and heighten the reproducibility of results for future research.

The effect of a single session submaximal aerobic exercise on premotor fraction of reaction time: an electromyographic study

BACKGROUND

Numerous studies investigating the effect of exercise on reaction time have yielded contradictory results. Most of the studies use computer based methods to measure reaction time instead of electromyography, yielding total reaction time rather than premotor time. In this study, we aimed to investigate the effect of a single session aerobic exercise on premotor fraction of reaction time in sedentary healthy individuals.

METHODS

Twenty-two sedentary healthy subjects (11 subjects for the study group and 11 for the control group) enrolled in this study. Subjects in the exercise group performed a single session submaximal cycling exercise. Electromyographic reaction times were measured before and after the exercise session. In the control group, reaction time measurements were taken twice with an interval of 20 min.

FINDINGS

In the exercise group, premotor fraction of reaction time values decreased considerably (P=0.01) after the exercise session.

INTERPRETATION

A single bout of cycling exercise significantly improved premotor fraction of reaction time in healthy young sedentary subjects. Physical activity improves not only physical fitness but also cognitive functions. Electromyographic reaction time evaluations may be used in the sports medicine field where both aerobic fitness and short reaction time are indispensable demands.

The Effect of a 12-week Combined Exercise Intervention Program on Physical Performance and Gait Kinematics in Community-dwelling Elderly Women

This study aimed to determine if combined exercise intervention improves physical performance and gait joint-kinematics including the joint angle and dynamic range of motion (ROM) related to the risk of falling in community-dwelling elderly women. A 12-week combined exercise intervention program with extra emphasis on balance, muscle strength, and walking ability was designed to improve physical performance and gait. Twenty participants attended approximately two-hour exercise sessions twice weekly for 12 weeks. Participants underwent a physical performance battery, including static balance, sit and reach, whole body reaction time, 10 m obstacle walk, 10 m maximal walk, 30-second chair stand, to determine a physical performance score, and received quantitative gait kinematics measurements at baseline and in 12 weeks. Significant lower extremity strength improvement 13.5% (p<.001) was observed, which was accompanied by significant decreases in time of the 10 m obstacle walk (p<.05) and whole body reaction time (p<.001) in this study. However, no significant differences were seen for static balance and flexibility from baseline. For gait kinematics, in the mid-swing phase, knee and hip joint angle changed toward flexion (p<.01, p<.05, respectively). Ankle dynamic ROM significantly increased (p<.05) following exercise intervention. The plantar flexion angle of the ankle in the toe-off phase was increased significantly (p<.01). However, other gait parameters were not significantly different from baseline. These findings from the present investigation provide evidence of significant improvements in physical performance related to the risk factors of falling and safe gait strategy with a combined exercise intervention program in community-dwelling elderly women. The results suggest this exercise intervention could be an effective approach to ameliorate the risk factors for falls and to promote safer locomotion in elderly community-dwelling women.

Components of Response Time as a Function of Age, Physical Activity, and Aerobic Fitness

Research suggests that there are differences in response time (RespT) as a function of age but that aerobic fitness might have a facilitatory effect on RespT. This study was designed to examine this relationship while addressing methodological issues from past research. Men from 3 age groups completed speeded tasks, a physical activity questionnaire, and an aerobic-fitness test. Results indicated that age has a negative impact on RespT (specifically premotor time and movement time). The interaction of aerobic fitness by age was also a significant predictor of RespT (specifically movement time) such that aerobic fitness was positively related to speed of performance for older participants. It is concluded that aerobic fitness might serve a preservative function for speeded tasks in older adults.

The Relationship of Physical Activity History to Pattern-Reversal Evoked-Potential Components in Young and Older Men and Women

Latencies and peak-to-peak amplitudes of pattern-reversal evoked-potential (PREP) components of active and inactive community-dwelling healthy 61- to 77-year-olds were compared with those of active and inactive 18- to 31-year-olds to determine whether long-term physical activity involvement was associated with attenuation of age-related changes in sensory processes. Binocular PREPs were derived for each of 2 check sizes (22 × 15 ft and 41 × 30 ft of visual angle) to provide increasing challenge of spatial resolution. Analyses of the latencies revealed significant effects for age, gender, and check size such that latencies were longer for older than for young participants, men than for women, and small than for larger check sizes. Amplitudes were larger in older adults for the P100-N150 peak-to-peak difference, but physical activity history was not associated with reduction of the observed age-related increases in component latencies and amplitude. As such, physical activity does not appear to attenuate age-related decline in visual sensory processing.

Effect of Aerobic Exercise on Tracking Performance in Elderly People: A Pilot Study

Background and Purpose. Although much is known about the benefits of aerobic exercise on cardiovascular health, little research has been done on the effect of aerobic exercise on motor performance. This study examined whether aerobic exercise has an effect on visuospatial information processing during finger-movement tracking in elderly subjects. Subjects. Fifteen elderly subjects (mean age=83.2 years, SD=5.7, range=72–91) from a senior housing complex were randomly assigned to a control group or an experimental (exercise) group. Twelve subjects completed the study, and data obtained for 10 subjects were used for data analysis (2 control subjects were eliminated to allow for matched-pairs analysis between the experimental and control groups). The control group (n=5) had a mean age of 80.2 years (SD=7.8). Subjects in the experimental group (n=5) had a mean age of 84.8 years (SD=2.5). Methods. The intervention consisted of group exercise 3 times a week for 8 consecutive weeks, and included calisthenics (eg, marching in place, side stepping, mock boxing), stationary bicycling, and walking. A finger-movement tracking test and submaximal graded exercise tolerance step tests were performed before and after training to determine changes in finger-movement tracking and any aerobic training effects. Results. Matched-pairs t tests showed a difference in tracking from pretest to posttest in the experimental group compared with the control group. Step test performance did not differ between the 2 groups. Discussion and Conclusion. The results of this small-scale study with a limited number of subjects indicate that, for elderly people, finger-movement tracking performance can improve with aerobic exercise, despite the absence of an aerobic training effect. Possible mechanisms for the treatment effect on information processing are discussed.

Effect of Task Complexity on the Relationship between Physical Fitness and Reaction Time in Older Women

Thirty-four women ages 60 to 75 years were divided into two groups based on self-reported physical activity levels. The presence of significant fitness differences between the two activity groups was confirmed by testing all subjects on a well-established submaximal mile walking test. Both groups performed a reaction time task under two levels of task complexity: simple reaction time (SRT) and complex choice reaction time (CCRT). Time to react in milliseconds was recorded for both levels of task complexity. Analysis of variance revealed that the active group reacted faster (p< .05) than the less active group on CCRT (activeM,1.100 sec; less activeM, 1.818 sec). However, SRT times did not differ between groups (activeM, .345 msec; less activeM, .374 msec). This finding lends support to the hypothesis that cognitive task complexity influences the strength of the association between physical fitness and cognitive performance in older adults.