A single aerobic exercise session accelerates movement execution but not central processing.

Previous research has demonstrated that aerobic exercise has disparate effects on speed of processing and movement execution. In simple and choice reaction tasks, aerobic exercise appears to increase speed of movement execution while speed of processing is unaffected. In the flanker task, aerobic exercise has been shown to reduce response time on incongruent trials more than congruent trials, purportedly reflecting a selective influence on speed of processing related to cognitive control. However, it is unclear how changes in speed of processing and movement execution contribute to these exercise-induced changes in response time during the flanker task. This study examined how a single session of aerobic exercise influences speed of processing and movement execution during a flanker task using electromyography to partition response time into reaction time and movement time, respectively. Movement time decreased during aerobic exercise regardless of flanker congruence but returned to pre-exercise levels immediately after exercise. Reaction time during incongruent flanker trials decreased over time in both an aerobic exercise and non-exercise control condition indicating it was not specifically influenced by exercise. This disparate influence of aerobic exercise on movement time and reaction time indicates the importance of partitioning response time when examining the influence of aerobic exercise on speed of processing. The decrease in reaction time over time independent of aerobic exercise indicates that interpreting pre-to-post exercise changes in behavior requires caution.

A single session of exercise as a modulator of short-term learning in healthy individuals.

BACKGROUND: A single session of aerobic exercise is linked to faster motor responses; however, the effect on rate of short-term learning is less clear. The objective was to evaluate the influence of a single bout of aerobic exercise on the rate of short-term acquisition of a shape-letter association task requiring a motor response. METHODS: 23 [11 females, age 20.8±2.7years] healthy young adults were evaluated using a randomly assigned crossover design which was counterbalanced for order before and after moderate (exercise) and light (control) intensity cycle ergometry. Participants performed 3 blocks, with each block consisting of one round of training and testing. During training, participants were tasked with learning 6 unique shape-letter associations. Subsequent testing required a key press response to a visually presented shape pattern. Response time and error rates were used to assess acquisition over the 3 blocks of testing. RESULTS: Mean response time was faster post-exercise relative to the other testing periods, and approached statistical significance compared to post-control (p<0.07). However, no significant difference in response time reduction (difference between test block 1 and test block 3) was identified between the four evaluations (pre and post the exercise and control conditions). Error rate reduction (test block 1 minus test block 3) revealed that individuals had the smallest change in error rate post-exercise (p<0.05). Follow-up analyses revealed fewer errors in test block 1 and test block 2 post-exercise which approached statistical significance (p=0.06) suggesting near-perfect error rates were obtained after only 2 testing blocks post-exercise compared to 3 blocks in the other testing periods. CONCLUSIONS: Support for augmentation of short-term learning was mixed as errors were reduced post-exercise while response time was not different between evaluations. Future work should include neurophysiological evaluation and a retention test to better elucidate the influence of aerobic exercise on rate of short-term learning.

The Influence of Parkinson's Disease Motor Symptom Asymmetry on Hand Performance: An Examination of the Grooved Pegboard Task.

This study examined the influence of motor symptom asymmetry in Parkinson's disease (PD) on Grooved Pegboard (GP) performance in right-handed participants. The Unified Parkinson's Disease Rating Scale was used to assess motor symptoms and separate participants with PD into two groups (right-arm affected, left-arm affected) for comparison with a group of healthy older adults. Participants completed the place and replace GP tasks two times with both hands. Laterality quotients were computed to quantify performance differences between the two hands. Comparisons among the three groups indicated that when the nonpreferred hand is affected by PD motor symptoms, superior preferred hand performance (as seen in healthy older adults) is further exaggerated in tasks that require precision (i.e., place task). Regardless of the task, when the preferred hand is affected, there is an evident shift to superior left-hand performance, which may inevitably manifest as a switch in hand preference. Results add to the discussion of the relationship between handedness and motor symptom asymmetry in PD.

Integrating aerobic training within subacute stroke rehabilitation: a feasibility study.

BACKGROUND: Aerobic activity positively affects patients recovering from stroke and is part of best practice guidelines, yet this evidence has not been translated to routine practice. OBJECTIVE: The objective of this study was to evaluate the feasibility of a model of care that integrated aerobic training in an inpatient rehabilitation setting for patients in the subacute stage of stroke recovery. Key elements of the program were personalized training prescription based on submaximal test results and supervision within a group setting. DESIGN: This was a prospective cohort study. METHODS: Participants (N=78) completed submaximal exercise testing prior to enrollment, and the test results were used by their treating physical therapists for exercise prescription. Feasibility was evaluated using enrollment, class attendance, adherence to prescription, and participant perceptions. RESULTS: Overall, 31 patients (40%) were referred to and completed the exercise program. Cardiac comorbidities were the main reason for nonreferral to the fitness group. Program attendance was 77%; scheduling conflicts were the primary barrier to participation. The majority of participants (63%) achieved 20 minutes of continuous exercise by the end of the program. No adverse events were reported, all participants felt they benefited from the program, and 80% of the participants expressed interest in continuing to exercise regularly after discharge. LIMITATIONS: Cardiac comorbidities prevented enrollment in the program for 27% of the admitted patients, and strategies for inclusion in exercise programs in this population should be explored. CONCLUSIONS: This individualized exercise program within a group delivery model was feasible; however, ensuring adequate aerobic targets were met was a challenge, and future work should focus on how best to include individuals with cardiac comorbidities.

Impact of a single bout of aerobic exercise on regional brain perfusion and activation responses in healthy young adults.

PURPOSE: Despite the generally accepted view that aerobic exercise can have positive effects on brain health, few studies have measured brain responses to exercise over a short time span. The purpose of this study was to examine the impact within one hour of a single bout of exercise on brain perfusion and neuronal activation. METHODS: Healthy adults (n = 16; age range: 20-35 yrs) were scanned using Magnetic Resonance Imaging (MRI) before and after 20 minutes of exercise at 70% of their age-predicted maximal heart rate. Pseudo-continuous arterial spin labeling (pcASL) was used to measure absolute cerebral blood flow (CBF) prior to exercise (pre) and at 10 min (post-10) and 40 min (post-40) post-exercise. Blood oxygenation level dependent (BOLD) functional MRI (fMRI) was performed pre and post-exercise to characterize activation differences related to a go/no-go reaction time task. RESULTS: Compared to pre-exercise levels, grey matter CBF was 11% (±9%) lower at post-10 (P<0.0004) and not different at post-40 (P = 0.12), while global WM CBF was increased at both time points post-exercise (P<0.0006). Regionally, the hippocampus and insula showed a decrease in perfusion in ROI-analysis at post-10 (P<0.005, FDR corrected), whereas voxel-wise analysis identified elevated perfusion in the left medial postcentral gyrus at post-40 compared to pre (pcorrected = 0.05). BOLD activations were consistent between sessions, however, the left parietal operculum showed reduced BOLD activation after exercise. CONCLUSION: This study provides preliminary evidence of regionalized brain effects associated with a single bout of aerobic exercise. The observed acute cerebrovascular responses may provide some insight into the brain's ability to change in relation to chronic interventions.

Physical activity in the prevention of ischemic stroke and improvement of outcomes: a narrative review.

Physical activity is an integral component of stroke prevention. Although approximately 80% of strokes are due to cerebral ischemia, the mechanisms linking physical activity to the incidence of and recovery from ischemic stroke are not completely understood. This review summarizes evidence from human and animal studies regarding physical activity in the prevention of overt and covert ischemic stroke and associated injury. In cohort studies, people who are physically active have reduced rates of overt ischemic stroke and ischemic stroke mortality. However, few human studies have examined physical activity and the incidence of covert stroke. Evidence from animal models of ischemic stroke indicates that physical activity reduces injury after ischemic stroke by reducing infarct size and apoptotic cell death. Accordingly, physical activity may reduce the magnitude of injury from ischemic stroke so that there are fewer or less severe symptoms. Future research should investigate physical activity and incidence of covert stroke prospectively, ascertain the optimal dose and type of exercise to prevent ischemic injury, and identify the underlying neuroprotective mechanisms.

The relationship between the grooved pegboard test and clinical motor symptom evaluation across the spectrum of Parkinson's disease severity.

BACKGROUND: The Unified Parkinson's Disease Rating Scale (UPDRS) is the gold standard for assessing Parkinsonian symptoms, yet objective outcome measures are needed to complement the UPDRS in research and clinical practice. OBJECTIVE: This study aimed to investigate the relationship between performance on the Grooved Pegboard Test (GP) and clinical assessment of Parkinson's motor symptoms with the UPDRS. METHODS: A large sample of individuals with Parkinson's disease (n = 191) were assessed with the GP and UPDRS motor section. The GP was separated into a place (more representative of visuospatial accuracy) and remove phase (general representation of motor speed and bradykinesia). Both tests were completed at peak anti-parkinsonian medication levels, and UPDRS subscores were calculated to represent upper-limb control, rigidity, bradykinesia, and tremor. A subsequent correlation analysis was completed. RESULTS: The strongest relationships were between the GP place phase (both limbs) and total UPDRS motor score (affected: r = 0.604, less-affected: r = 0.587), upper-limb control (affected: r = 0.367, less-affected: r = 0.426), rigidity (affected: r = 0.479, less-affected: r = 0.457) and body bradykinesia (affected: r = 0.375, less-affected: r = 0.438). The GP remove phase had weak positive relationships with total UPDRS scores (affected: r = 0.31, less-affected r = 0.31) and body bradykinesia (r = 0.31). CONCLUSIONS: Clinical assessment of upper-limb control, rigidity and bradykinesia are well represented by the GP place phase. Interestingly, it appeared that GP performance of the more affected limb may be more representative of motor severity in the early stages of disease, while more research is needed to understand the utility of the GP in the advanced stages of disease.

A positive influence of vision on motor symptoms during sensory attention focused exercise for Parkinson's disease.

This study evaluated the effect of increased attention to sensory feedback during exercise. Two 12-week exercise programs that differed only in the presence (PD SAFEx) or absence (non-SAFE control group) of increased attention focused on sensory feedback were compared. Participants were assessed symptomatically using the Unified Parkinson's Disease Rating Scale (UPDRS) before the start of the exercise program, immediately following the 12-week program and after a 6-week nonexercise washout period. Secondary outcome measures included the Timed-Up-and-Go (TUG), Grooved Pegboard (GP) and velocity and step length of self-paced gait. Both groups significantly improved on the TUG, GP, velocity, and step length, and this was maintained after a 6-week washout period. Of additional interest, only the PD SAFEx program significantly improved motor symptoms (UPDRS). These gains were maintained in the PD SAFEx group 6 weeks after the exercise was stopped, while motor symptoms significantly worsened in the non-SAFE group. These results suggest that increasing awareness of sensory feedback may be a critical factor that specifically impacts motor symptoms. Future work should strive to uncover the underlying neurophysiological mechanism behind this effect.

Symptom and gait changes after sensory attention focused exercise vs aerobic training in Parkinson's disease.

The current study compared lower-limb aerobic training and sensory attention focused exercise (PD SAFEx) to a non-exercise control group with the overall objective of determining which strategy would have a greater benefit for Parkinson's disease (PD) symptoms and gait. PD SAFEx was developed to focus on sensorimotor deficits identified in PD with the aim of increasing sensory feedback and body awareness, while the lower-limb aerobic training utilized a specially designed semi-recumbent elliptical device. Intervention groups (PD SAFEx, n = 18; aerobic, n = 13) exercised three times/week for 10-12 weeks, while nonexercise control participants (n = 15) maintained their regular activity level for 12 weeks. Outcome measures included the Unified Parkinson's disease rating scale motor section (UPDRS) administered by a blinded clinician; a posture and gait (PG) score (total of UPDRS items 27-31); the Timed-Up-and-Go (TUG); and spatiotemporal aspects of self-paced gait. PD SAFEx resulted in an improved UPDRS, PG score, and TUG (reached significance when participants with poor attendance were excluded) but not self-paced gait. The lower-limb aerobic training led to increased step length and velocity but had no change to disease severity. Since gait improvements were not combined with symptomatic changes, lower-limb aerobic exercise may not be optimal for individuals with PD. Conversely, sensory-based exercise (PD SAFEx) was beneficial, and led to improvement in symptoms and functional movement control.