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

Rapid Inhibition Accuracy and Leg Strength Are Required for Community-Dwelling Older People to Recover Balance From Induced Trips and Slips: An Experimental Prospective Study

BACKGROUND AND PURPOSE

Falls can result in bone fractures and disability, presenting a serious threat to quality of life and independence in older adults. The majority of falls in community-living older adults occur while walking and are often caused by trips and slips. The study aimed to identify the specific sensorimotor and psychological factors required for older adults to recover balance from trips and slips.

METHODS

Forty-one older adults aged 65 to 87 years were assessed on sensorimotor (knee extension strength, proprioception, postural sway, and edge contrast sensitivity), reaction (simple reaction time, stepping, and catching reaction inhibition), and psychological (general anxiety and concern about falling) measures. Using a harness system, participants walked at 90% of their usual pace on a 10-m walkway that could induce trips and slips in concealed and changeable locations. Post-perturbation responses resulting in more than 30% of body weight being recorded by the harness system were defined as falls. Poisson regressions were used to test associations between the sensorimotor, reaction, and psychological measures and number of falls.

RESULTS

Fifty-one falls occurred in 25 of 41 participants. Poisson regression revealed body mass index, lower-limb proprioception, knee extension strength, rapid inhibition accuracy, concern about falling, and anxiety were significantly associated with the rate of falls. Other measures including postural sway were not statistically significant. Using stepwise Poisson regression analyses, normalized knee extension strength (rate ratio [RR]: 0.68, 95% confidence interval [CI]: 0.47-0.98), and rapid inhibition accuracy (RR: 0.64, 95% CI: 0.46-0.87) were independently associated with falls.

CONCLUSION

Our findings suggest rapid inhibition accuracy and adequate leg strength are required for older adults to recover balance from trips and slips. The mechanisms for balance recovery during daily life activities are likely different from those for static balance, suggesting the need for task-specific assessments and interventions for fall prevention in older adults.

COVID-19 Quarantine Impact on Wellbeing and Cognitive Functioning During a 10-Week High-Intensity Functional Training Program in Young University Students

Physical exercise can improve cognitive functioning and wellbeing; however, the degree of change in either of these two variables seems to be related to the exercise intensity or type. Therefore, new physical training (PT) programs have been developed to increase exercise efficiency. One such example is high-intensity functional training (HIFT), which has proven to be a time-efficient and highly effective strategy to improve physical fitness. This study analyzed whether HIFT can affect reaction time (RT) and vitality, as well as positive and negative affect. Forty-two college students participated in the study, 21 in the experimental group and 21 in the control group. The experimental group completed 10 weeks of training, five of which were supervised, and the remainder consisted of online training during the COVID-19 quarantine. Participants were evaluated at the beginning, at the end of the 5 weeks of supervised training, and after the 5 weeks of online training. HIFT improved RT without changes in psychological wellbeing during the entire period of training supervised and online. Therefore, during the HIFT program, the quarantine situation did not adversely affect this population’s wellbeing, but it did negatively affect adherence to the training program.

Acute high-intensity and moderate-intensity interval exercise do not change corticospinal excitability in low fit, young adults

Previous research has demonstrated a lack of neuroplasticity induced by acute exercise in low fit individuals, but the influence of exercise intensity is unclear. In the present study, we assessed the effect of acute high-intensity (HI) or moderate-intensity (MOD) interval exercise on neuroplasticity in individuals with low fitness, as determined by a peak oxygen uptake (VO2peak) test (n = 19). Transcranial magnetic stimulation (TMS) was used to assess corticospinal excitability via area under the motor evoked potential (MEP) recruitment curve before and following training. Corticospinal excitability was unchanged after HI and MOD, suggesting no effect of acute exercise on neuroplasticity as measured via TMS in sedentary, young individuals. Repeated bouts of exercise, i.e., physical training, may be required to induce short-term changes in corticospinal excitability in previously sedentary individuals.

IMPROVEMENT OF REACTION TIME AFTER A WORKPLACE PHYSICAL ACTIVITY INTERVENTION

ABSTRACT Introduction Work activities have been occupying an increasing amount of time in the daily lives of the population, making individuals less physically active. A job market strategy is to invest in physical exercise programs in the actual workplace to improve the physical and cognitive aspects of these employees. Objective To verify the effects of a workplace physical exercise program on the simple and choice reaction times of public university employees. Methods Twenty-six physically inactive male and female subjects with a mean age of 29.62 ± 6.47 years underwent a program consisting of thirty-six sessions with physical exercises in the workplace, held three times a week over twelve weeks. Simple reaction time (SRT) and choice reaction time (CRT) were assessed before and after the intervention, using the Vienna Test System®, and the results were presented in: I) reaction time, II) movement time; and (III) response time. Descriptive and inferential statistical analyses were conducted using the statistical program SPSS® (version 21.0 for Windows), with a significance level of 5%. Results When observing the SRT and CRT variables before and after the experiment, we noticed an improvement in reaction time, movement time and response time in the experimental group but not in the control group. Conclusion The workplace physical exercise program was able to reduce the SRT and CRT of the experimental group. Level of evidence I; randomized clinical trial.

Exercise-Induced Neuroplasticity: A Mechanistic Model and Prospects for Promoting Plasticity

Aerobic exercise improves cognitive and motor function by inducing neural changes detected using molecular, cellular, and systems level neuroscience techniques. This review unifies the knowledge gained across various neuroscience techniques to provide a comprehensive profile of the neural mechanisms that mediate exercise-induced neuroplasticity. Using a model of exercise-induced neuroplasticity, this review emphasizes the sequence of neural events that accompany exercise, and ultimately promote changes in human performance. This is achieved by differentiating between neuroplasticity induced by acute versus chronic aerobic exercise. Furthermore, this review emphasizes experimental considerations that influence the opportunity to observe exercise-induced neuroplasticity in humans. These include modifiable factors associated with the exercise intervention and nonmodifiable factors such as biological sex, ovarian hormones, genetic variations, and fitness level. To maximize the beneficial effects of exercise in health, disease, and following injury, future research should continue to explore the mechanisms that mediate exercise-induced neuroplasticity. This review identifies some fundamental gaps in knowledge that may serve to guide future research in this area.

The effects of acute bout of cycling on auditory & visual reaction times

AIM

The purpose of this study was to investigate the effects of an acute bout of cycling exercise on auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction time.

METHODS

29 subjects were randomly divided into experimental and control groups. The subjects of the experimental group carried out a single bout of submaximal cycling exercise. The auditory choice reaction time, visual choice reaction time, auditory complex choice reaction time and visual complex choice reaction times were measured before and after the exercise session. The reaction time tests were taken from the subjects by using Speed Anticipation and Reaction Tester (SART) software. In the control group, the reaction time tests were performed by the subjects with an interval of 30 min.

RESULTS

In the experimental group, the percentage changes of mean auditory choice and complex choice reaction time values were significantly decreased in comparison with the control group (P < 0.05). Although the visual choice and complex choice reaction times were decreased after the exercise, the changes were not significant (P > 0.05).

CONCLUSION

An acute bout of cycling exercise improved the speed of auditory and visual reaction times in healthy young females. However, these positive changes were significantly observed only in the auditory reaction time tests in comparison with the control group.

Effectiveness of intensive inpatient rehabilitation treatment on disease progression in parkinsonian patients: a randomized controlled trial with 1-year follow-up

BACKGROUND

Rehabilitation treatments have acute beneficial effects in Parkinson's disease (PD) patients, but whether the effects persist over time is unclear.

OBJECTIVE

To assess whether an intensive rehabilitation treatment (IRT) is effective in improving motor performance compared with a control group in a 12-month follow-up, to investigate whether a second cycle administered after 1 year has the same efficacy as the first treatment, and to determine whether IRT reduces the need for increasing levodopa dosage.

METHODS

A total of 50 PD patients were randomly assigned to 2 groups; 25 participants had 4 weeks of inpatient physical therapy that included treadmill and stabilometric platform training. At discharge, these patients were invited to continue doing the learned exercises. After 12 months, the same treatment was repeated. The control group of 25 patients received only pharmacological treatment and was invited to practice generic physical exercise at home. The rating scales used for the clinical evaluation were the Unified Parkinson's Disease Rating Scale Sections II and III (UPDRS II and III) and total (UPDRS tot).

RESULTS

The authors found that the beneficial effects of IRT persisted over time. A second rehabilitation cycle administered after 1 year was as effective as the first treatment. At the end of the study, daily medication dosage was reduced in treated patients, whereas it was significantly increased in control patients.

CONCLUSION

These findings suggest that the natural worsening of symptoms associated with PD can be effectively counteracted by a properly designed IRT.

Lower limb muscle pre-motor time measures during a choice reaction task associate with knee abduction loads during dynamic single leg landings

BACKGROUND

Female neuromuscular control during dynamic landings is considered central to their increased ACL injury risk relative to males. There is limited insight, however, into the neuromuscular parameters governing this risk, which may hinder prevention success. This study targeted a new screenable and potentially trainable neuromuscular risk factor. Specifically, we examined whether lower limb muscle pre-motor times, being the time between stimulus presentation and initiation of the muscle EMG burst, elicited during a simple choice reaction task correlated with knee abduction loads during separate single leg landings.

METHODS

Twenty female NCAA athletes had muscle (n=8) pre-motor time and knee biomechanics data recorded bilaterally during a choice reaction task. Knee biomechanics were also quantified during anticipated and unanticipated single (dominant and non-dominant) leg landings. Mean peak knee abduction loads during landings were submitted to a two-way ANOVA to test for limb and decision effects. Individual regression coefficients were initially computed between-limb-based muscle pre-motor times and peak abduction moments elicited during both the choice reaction and landing tasks. Limb-based linear stepwise regression coefficients were also computed between muscle PMT's demonstrating significant (P<0.05) individual associations and peak knee abduction moments during landings.

FINDINGS

Peak knee abduction moments were significantly (P=0.0001) larger during unanticipated (51.25 (7.41) Nm) compared to anticipated (38.93 (9.32) Nm) landings. Peak abduction moments were significantly (P<0.05) correlated with bilateral medial gastrocnemius (r=0.62 dominant; r=0.63 non-dominant) and medial hamstring (r=0.77 dominant; r=0.79 non-dominant) pre-motor times elicited within the choice reaction task. Peak abduction moments during anticipated landings were significantly (P<0.05) correlated with both dominant (r=0.60) and non-dominant (r=0.59) medial hamstring pre-motor times. For unanticipated landings, non-dominant and dominant peak knee abduction moments were significantly correlated with medial hamstring pre-motor time (r=0.78) and combined medial gastroc and medial hamstring pre-motor times (r=0.94) respectively.

INTERPRETATION

Medial muscle pre-motor times during a specific choice reaction task are associated with peak knee abduction loads during separate single leg landings. These muscles appear critical in stabilizing the knee against the extreme dynamic load states associated with such tasks. Targeted screening and training of supraspinal processes governing these muscle pre-motor times may ultimately enable external knee loads associated with landings to be more effectively countered by the overarching neuromuscular strategy.