Hippocampal Functional Connectivity and Memory Performance After Exercise Intervention in Older Adults with Mild Cognitive Impairment.

BACKGROUND: Exercise training (ET) has neuroprotective effects in the hippocampus, a key brain region for memory that is vulnerable to age-related dysfunction. OBJECTIVE: We investigated the effects of ET on functional connectivity (FC) of the hippocampus in older adults with mild cognitive impairment (MCI) and a cognitively normal (CN) control group. We also assessed whether the ET-induced changes in hippocampal FC (Δhippocampal-FC) are associated with changes in memory task performance (Δmemory performance). METHODS: 32 older adults (77.0±7.6 years; 16 MCI and 16 CN) participated in the present study. Cardiorespiratory fitness tests, memory tasks (Rey Auditory Verbal Learning Test (RAVLT) and Logical Memory Test (LM)), and resting-state fMRI were administered before and after a 12-week walking ET intervention. We utilized a seed-based correlation analysis using the bilateral anterior and posterior hippocampi as priori seed regions of interest. The associations of residualized ET-induced Δhippocampal-FC and Δmemory performance were assessed using linear regression. RESULTS: There were significant improvements in RAVLT Trial 1 and LM test performance after ET across participants. At baseline, MCI, compared to CN, demonstrated significantly lower posterior hippocampal FC. ET was associated with increased hippocampal FC across groups. Greater ET-related anterior and posterior hippocampal FC with right posterior cingulate were associated with improved LM recognition performance in MCI participants. CONCLUSION: Our findings indicate that hippocampal FC is significantly increased following 12-weeks of ET in older adults and, moreover, suggest that increased hippocampal FC may reflect neural network plasticity associated with ET-related improvements in memory performance in individuals diagnosed with MCI.

Treadmill Exercise Alleviates Brain Iron Dyshomeostasis Accelerating Neuronal Amyloid-ß Production, Neuronal Cell Death, and Cognitive Impairment in Transgenic Mice Model of Alzheimer's Disease.

Brain iron increases with age and abnormal brain iron metabolism is proving increasingly likely to be involved in the pathology of Alzheimer's disease (AD). The iron-regulatory effect of furin, a ubiquitously expressed proconvertase, might play an important role in AD. Therefore, there is an urgent need to study the effect of furin on iron regulation in AD. For that purpose, we aimed to determine the role of physical exercise in AD associated with brain iron dyshomeostasis. Treadmill exercise attenuated the AD-related abnormal brain iron regulation by furin in vivo, as demonstrated via experiments in aged APP-C105 mice. Next, we examined whether treadmill exercise decreases excessive iron, directly affecting amyloid-ß (Aß) production through the regulation of α-secretase-dependent processing of amyloid protein precursor (APP) involved in the modulation of furin activity. We first observed that cognitive decline and Aß-induced neuronal cell death were induced by disruption of APP processing via excess iron-induced disruption of furin activity in aged APP-C105 mice. The induced cognitive decline and cell death were attenuated by treadmill exercise. This result suggests that treadmill exercise alleviated cognitive decline and Aß-induced neuronal cell death by promoting α-secretase-dependent processing of APP through low iron-induced enhancement of furin activity. This is concomitant with decreasing levels of lipid peroxidation products and promoting antioxidant defense enzyme capacities. Therefore, iron-targeted therapeutic strategies involving treadmill exercise might be useful for patients with AD.

Mild regular treadmill exercise ameliorated the detrimental effects of acute sleep deprivation on spatial memory.

Vulnerable areas like the hippocampus are sensitive to insults such as sleep deprivation (SD); they are also susceptible to environmental enrichment. Much evidence is accumulating that chronic sleep deprivation causes alterations in the hippocampus that responsible for spatial memory. However, there is conflicting about the differences between acute and chronic SD results. The purpose of this study was to determine the protective effects of mild treadmill exercise on acute SD rats. Four groups were created as control, exercise, sleep deprivation, exercise + sleep deprivation. Multiple platforms method was used to induce REM sleep deprivation (RD) for 48 h. The exercise was applied fivedaysperweekforfour weeks(5 × 4). For the first and second weeks, the length of the exercise was 15 min in two sessions (5 min interval) followed by 15 min in three, 15 min in four sessions. Morris water maze (MWM) was used as a spatial memory test. Gene level was determined by using the qPCR technique. Malondialdehyde (MDA) content in the hippocampus was measured as an extent of peroxidative damage to lipids by using the ELISA method. 48 h RD impaired long-term spatial memory significantly. Mild, regular treadmill exercise ameliorated the detrimental effects of acute sleep deprivation on memory. There was no significant difference in MDA between groups. Hippocampal gene expression did not show any changes in all groups. Lack of correlation between memory impairment and levels of genes in the hippocampus is likely to be related to the differences in behavioral and genetic mechanisms.

Moderate Intensity Treadmill Exercise Increases Survival of Newborn Hippocampal Neurons and Improves Neurobehavioral Outcomes after Traumatic Brain Injury.

Physician-prescribed rest after traumatic brain injury (TBI) is both commonplace and an increasingly scrutinized approach to TBI treatment. Although this practice remains a standard of patient care for TBI, research of patient outcomes reveals little to no benefit of prescribed rest after TBI, and in some cases prolonged rest has been shown to interfere with patient well-being. In direct contrast to the clinical advice regarding physical activity after TBI, animal models of brain injury consistently indicate that exercise is neuroprotective and promotes recovery. Here, we assessed the effect of low and moderate intensity treadmill exercise on functional outcome and hippocampal neural proliferation after brain injury. Using the controlled cortical impact (CCI) mouse model of TBI, we show that 10 days of moderate intensity treadmill exercise initiated after CCI reduces anxiety-like behavior, improves hippocampus-dependent spatial memory, and promotes hippocampal proliferation and newborn neuronal survival. Pathophysiological measures including lesion volume and axon degeneration were not altered by exercise. Taken together, these data reveal that carefully titrated physical activity may be a safe and effective approach to promoting recovery after brain injury.

The sensory representation of causally controlled objects.

Intentional control over external objects is informed by our sensory experience of them. To study how causal relationships are learned and effected, we devised a brain machine interface (BMI) task using wide-field calcium signals. Mice learned to entrain activity patterns in arbitrary pairs of cortical regions to guide a visual cursor to a target location for reward. Brain areas that were normally correlated could be rapidly reconfigured to exert control over the cursor in a sensory-feedback-dependent manner. Higher visual cortex was more engaged when expert but not naive animals controlled the cursor. Individual neurons in higher visual cortex responded more strongly to the cursor when mice controlled it than when they passively viewed it, with the greatest response boosting as the cursor approached the target location. Thus, representations of causally controlled objects are sensitive to intention and proximity to the subject's goal, potentially strengthening sensory feedback to allow more fluent control.

Metabolic and Neurocognitive Changes Following Lifestyle Modification: Examination of Biomarkers from the ENLIGHTEN Randomized Clinical Trial.

BACKGROUND: Previous studies have demonstrated that aerobic exercise (AE) and the Dietary Approaches to Stop Hypertension (DASH) diet can improve neurocognition. However, the mechanisms by which lifestyle improves neurocognition have not been widely studied. We examined the associations between changes in metabolic, neurotrophic, and inflammatory biomarkers with executive functioning among participants from the Exercise and Nutritional Interventions for Neurocognitive Health Enhancement (ENLIGHTEN) trial. OBJECTIVE: To examine the association between changes in metabolic function and neurocognition among older adults with cognitive impairment, but without dementia (CIND) participating in a comprehensive lifestyle intervention. METHODS: ENLIGHTEN participants were randomized using a 2×2 factorial design to receive AE, DASH, both AE+DASH, or a health education control condition (HE) for six months. Metabolic biomarkers included insulin resistance (homeostatic model assessment [HOMA-IR]), leptin, and insulin-like growth factor (IGF-1); neurotrophic biomarkers included brain derived neurotrophic factor (BDNF) and vascular endothelial growth factor (VEGF); and inflammatory biomarkers included interleukin-6 (IL-6) and C-Reactive Protein (CRP). RESULTS: Participants included 132 sedentary older adults (mean age = 65 [SD = 7]) with CIND. Results demonstrated that both AE (d = 0.48, p = 0.015) and DASH improved metabolic function (d = 0.37, p = 0.039), without comparable improvements in neurotrophic or inflammatory biomarkers. Greater improvements in metabolic function, including reduced HOMA-IR (B = -2.3 [-4.3, -0.2], p = 0.033) and increased IGF-1 (B = 3.4 [1.2, 5.7], p = 0.004), associated with increases in Executive Function. CONCLUSION: Changes in neurocognition after lifestyle modification are associated with improved metabolic function.

Comparison of the effects of treadmill and vibration training in children with attention deficit hyperactivity disorder: A randomized controlled trial.

OBJECTIVE: The aim of this study was to compare the effects of treadmill training (TT) and whole body vibration training (WBVT) on attention, severity of attention deficit hyperactivity disorder (ADHD) symptoms and impairment of executive function behaviors, and quality of life in children with ADHD. METHODS: Thirty children (7-11 years of age) with ADHD were randomly assigned to either the 'TT' group or the 'WBVT in addition to TT' group (TT + WBVT). Both groups received TT for 8 weeks (3 days/week). The TT + WBWT group also received WBVT for 15 minutes. Stroop Test TBAG form, Behavior Rating Inventory of Executive Function (BRIEF), Conners' Rating Scale (CRS) and Pediatric Quality of Life Inventory (PedsQL) were applied at baseline and after 8 weeks of training. RESULTS: All assessment results significantly improved in both groups at the end of the program compared to baseline values (p < 0,05). There were significant differences between groups regarding improvements in CTRS-R/L and BRIEF-Teacher form in favor of the TT + WBVT group. CONCLUSIONS: The findings suggest that exercise training including TT and WBVT might be used in the treatment of ADHD but further research is required to provide evidence of the effectiveness of the whole body vibration training in the management of ADHD.

Cerebellar transcranial direct current stimulation for learning a novel split-belt treadmill task: a randomised controlled trial.

This study aimed to examine the effect of repeated anodal cerebellar transcranial direct current stimulation (ctDCS) on learning a split-belt treadmill task. Thirty healthy individuals randomly received three consecutive sessions of active or sham anodal ctDCS during split-belt treadmill training. Motor performance and strides to steady-state performance were evaluated before (baseline), during (adaptation), and after (de-adaptation) the intervention. The outcomes were measured one week later to assess absolute learning and during the intervention to evaluate cumulative, consecutive, and session-specific effects. Data were analysed using linear mixed-effects regression models. During adaptation, there was no significant difference in absolute learning between the groups (p > 0.05). During de-adaptation, a significant difference in absolute learning between the groups (p = 0.03) indicated slower de-adaptation with anodal ctDCS. Pre-planned secondary analysis revealed that anodal ctDCS significantly reduced the cumulative (p = 0.01) and consecutive-session effect (p = 0.01) on immediate adaptation. There were significant cumulative (p = 0.02) and session-specific effects (p = 0.003) on immediate de-adaptation. Repeated anodal ctDCS does not enhance motor learning measured during adaptation to a split-belt treadmill task. However, it influences the maintenance of learnt walking patterns, suggesting that it may be beneficial in maintaining therapeutic effects.

Endurance training exerts time-dependent modulation on depressive responses and circadian rhythms of corticosterone and BDNF in the rats with pinealectomy.

Pinealectomy can cause a disturbance in emotional status and circadian rhythms of the endocrine and metabolic functions in the body. Endurance training is considered a part of the complex therapy of dysfunctions driven by changes in circadian dynamics of many physiological indicators. In the present study, we aimed to study the effect of endurance training on depressive behavior induced by pinealectomy in rat. We tested the hypothesis that endurance training can have a beneficial impact on depressive behavior induced by pinealectomy in rat via correction of desynchronized circadian rhythms of corticosterone secretion in plasma and brain-derived neurothrophic factor (BDNF) in the hippocampus. The continuous exercise program attenuated depressive responses characterized by the disrupted diurnal rhythm of home-cage motor activity, anhedonia in the sucrose preference test, decreased grooming in the splash test, and despair-like behavior in the forced swimming test of rats with pinealectomy to values resembling those of sham-treated controls. Parallel to the observed positive effect on the emotional status, exercise training diminished total plasma corticosterone levels and corrected its flattened pattern. While the melatonin deficiency did not affect the fluctuations of the BDNF levels, the exercise program induced a considerable and time-dependent increase in its level. These findings suggest that the antidepressant-like effect of endurance training might be mediated via correction of the disturbed circadian rhythm of corticosterone release and enhancement of hippocampal BDNF levels in rats with pinealectomy. Therefore, this alternative mode might have a potential therapeutic application in a subpopulation of people characterized by a melatonin deficiency.

Time-course of running treadmill adaptation in novice treadmill runners.

Studies on running biomechanics and energetics are usually conducted on a treadmill. To ensure that locomotion on a treadmill is comparable to locomotion overground, participants need to be expert in the use of the device. This study aimed to identify the number and duration of sessions needed to obtain stable measurements for spatiotemporal and metabolic parameters in unexperienced treadmill runners. Fourteen male recreational runners performed three 15-min treadmill running trials in different days at a submaximal speed. Spatiotemporal and metabolic parameters were registered at minutes: 5, 10, 15 and their within-trial and between-trial changes were analysed using a two-way repeated measures ANOVA and Bonferroni post-hoc test. Within-trial differences were found in step frequency (decreased over time), Step Length and Contact Time (increased), reaching stability at different time points. Ventilator parameters increased, reaching stability after 5-10 min, while heart rate increased progressively over time. The only between-trial differences were an increase in step length and a decrease in step frequency at min 1, between trials 1 and 3. In conclusion, at least three running trials of 15 min are required to familiarize with the device. The last 5 min of the third trial can be regarded as stable measurements.

Physical activity in people with epilepsy: A systematic review.

This study aimed to systematically review studies focusing on levels of physical activity (PA) in people with epilepsy (PWE) compared with non-epilepsy controls, and identify factors associated with PA in PWE. Intervention studies were also reviewed to consider the effects of psychological interventions on levels of PA, and the effects of PA-based interventions on seizure activity, psychiatric comorbidity, and health-related quality of life (HRQoL). PRISMA guidelines were followed. Searches were conducted using PubMed, Cochrane Controlled Register of Trials, PsycINFO, and Embase. Forty-six studies met inclusion criteria, including case-control, cross-sectional, and intervention studies. Assessment measures included questionnaires, activity trackers, and measures of physiological fitness. Twelve of 22 (54.5%) case-control studies utilizing self-report questionnaire measures reported that PWE were performing lower levels of PA, less likely to be engaging in PA, or less likely to meet PA guidelines than controls. The remaining studies did not find a difference between PWE and controls. Eight of 12 (67%) case-control studies utilizing exercise/fitness tests reported that PWE performed significantly poorer than controls, whereas in two studies PWE performed better than controls. One of three studies investigating the relationship between PA and seizure frequency found that increased self-reported PA was associated with having fewer seizures, whereas two did not find a significant relationship. All seven cross-sectional studies that included measures of HRQoL and depression/anxiety found a positive relationship between levels of PA and HRQoL/reduced levels of depression and anxiety. All four studies that used PA-based interventions demonstrated improvements in levels of PA and increased HRQoL. Study quality was almost universally low. In conclusion, there is some evidence that PWE engage in less PA than peers, and that interventions can improve PA levels and HRQoL. However, there is a need for more robust study designs to better understand PA in individuals with epilepsy.

Effect of an interdisciplinary intervention with motivational approach on exercise capacity in obese adolescents: a randomized controlled clinical trial.

Objective To evaluate the effect of an interdisciplinary intervention with a motivational approach on exercise capacity and usual physical activity levels in overweight and obese adolescents. Methods This is a randomized, controlled clinical trial with single blinding of subjects. Adolescents aged 15 to 18 years with overweight and obesity (body mass index ≥ 85 percentile) were included. The adolescents were randomized into two groups: interdisciplinary intervention or control - traditional approach aiming at lifestyle modifications. The initial evaluations were carried out, including the cardiopulmonary exercise test and the physical activity level measurement by using the International Physical Activity Questionnaire and a pedometer. The evaluations were performed in two moments: time zero (time of inclusion in the study) and after 3 months (end of intervention). There were 12 sessions with weekly meetings. Results A total of 37 participants were included, 19 in the Intervention Group. There were no significant differences in the baseline demographic, anthropometric and physical activity characteristics between groups, with mean age of 17.3±1.0 years in the Control Group, and 16.8±0.9 years in the Intervention Group (p=0.14). The motivational intervention did not cause significant differences (p>0.05) in the comparison of the variables of exercise capacity and usual physical activity (questionnaire and pedometer) between groups. Conclusion The intervention with a motivational approach did not alter exercise capacity and levels of usual physical activity in overweight and obese adolescents. Clinical Trial Registry: NCT02455973 and REBEC: RBR-234nb5.

Treadmill exercise promotes neurogenesis and myelin repair via upregulating Wnt/ß­catenin signaling pathways in the juvenile brain following focal cerebral ischemia/reperfusion.

Physical exercise has a neuroprotective effect and is an important treatment after ischemic stroke. Promoting neurogenesis and myelin repair in the penumbra is an important method for the treatment of ischemic stroke. However, the role and potential mechanism of exercise in neurogenesis and myelin repair still needs to be clarified. The goal of the present study was to ascertain the possible effect of treadmill training on the neuroprotective signaling pathway in juvenile rats after ischemic stroke. The model of middle cerebral artery occlusion (MCAO) in juvenile rats was established and then the rats were randomly divided into 9 groups. XAV939 (an inhibitor of the Wnt/ß­catenin pathway) was used to confirm the effects of the Wnt/ß­catenin signaling pathway on exercise­mediated neurogenesis and myelin repair. Neurological deficits were detected by modified neurological severity score, the injury of brain tissue and the morphology of neurons was detected by hematoxylin­eosin staining and Nissl staining, and the infarct volume was detected by 2,3,5­triphenyl tetrazolium chloride staining. The changes in myelin were observed by Luxol fast blue staining. The neuron ultrastructure was observed by transmission electron microscopy. Immunofluorescence and western blots analyzed the molecular mechanisms. The results showed that treadmill exercise improved neurogenesis, enhanced myelin repair, promoted neurological function recovery and reduced infarct volume. These were the results of the upregulation of Wnt3a and nucleus ß­catenin, brain­derived neurotrophic factor (BDNF) and myelin basic protein (MBP). In addition, XAV939 inhibited treadmill exercise­induced neurogenesis and myelin repair, which was consistent with the downregulation of Wnt3a, nucleus ß­catenin, BDNF and MBP expression, and the deterioration of neurological function. In summary, treadmill exercise promotes neurogenesis and myelin repair by upregulating the Wnt/ß­catenin signaling pathway, to improve the neurological deficit caused by focal cerebral ischemia/reperfusion.

Reliability of Knee Flexion-Extension Lyapunov Exponent in People With and Without Anterior Cruciate Ligament Deficiency.

OBJECTIVES: The current study assessed the intrasession and intersession reliability of the knee flexion-extension Lyapunov exponent in patients with anterior cruciate ligament deficiency and healthy individuals. STUDY DESIGN: University research laboratory. METHODS: Kinematic data were collected in 14 patients with anterior cruciate ligament deficiency and 14 healthy individuals walked on a treadmill at a self-selected, low, and high speed, with and without cognitive load. The intraclass correlation coefficient, standard error of measurement, minimal metrically detectable change, and percentage of coefficient of variation were calculated to assess the reliability. RESULTS: The knee flexion-extension Lyapunov exponent had high intrasession reliability, with intraclass correlation coefficients ranging from .83 to .98. In addition, the intersession intraclass correlation coefficient values of these measurements ranged from .35 to .85 regardless of group, gait speed, and dual tasking. In general, relative and absolute reliability were higher in the patients with anterior cruciate ligament deficiency than in the healthy individuals. CONCLUSIONS: Although knee flexion-extension Lyapunov exponent demonstrates good intrasession reliability, its low intersession reliability indicates that changes of these measurements between different days should be interpreted with caution.

Dual-task prioritization during overground and treadmill walking in healthy adults.

BACKGROUND: The dual-task effect on walking performance is different during treadmill and overground walking, though the cause of this difference is unknown. This study examined the effects of task prioritization on overground and treadmill dual-task walking. METHOD: Twenty-two adults walked overground and on a treadmill under three dual-task conditions: prioritization of walking performance, prioritization of cognitive performance (serial subtraction in sevens), or no prioritization. RESULTS: Compared to single-task walking, stride velocity was reduced and stride time variability was increased during dual-task overground walking. During treadmill walking, there was no dual-task effect on walking performance, but cognitive task performance was improved. Prioritization of the cognitive task reduced the dual-task effect on stride velocity during overground walking only, whilst prioritization of the walking task reduced cognitive task performance in both walking modalities. SIGNIFICANCE: These results corroborate recent findings that the dual-task effects on treadmill walking are not equivalent to those on overground walking. Healthy adults appear to prioritize cognitive task performance during treadmill dual-task walking without detrimental effects to gait. During overground walking however, allocation of attention to the secondary task reduces gait performance. These results indicate that treadmill based dual-task paradigms should not be used to infer factors which influence the cognitive control of overground walking.

The placebo effect on aerobic fitness test results is preserved following a multidisciplinary intervention program for treating childhood obesity.

BACKGROUND: The aim of the study was to examine the placebo effect on fitness test results in trained and untrained overweight and obese children. METHODS: Twenty pre-pubertal overweight children performed two pairs of progressive treadmill exercise tests before and 12 weeks into a multidisciplinary program for the treatment of childhood obesity. In each test pair, at random order, participants received different types of information regarding a water drink consumed prior to testing-standard information (water) vs deliberate positive information (presumed energy drink, placebo). RESULTS: The intervention led to a significant change (P < .05) in BMI%ile (95.6 ± 4.4 vs 93.6 ± 6.9), % fat (35.4 ± 6.0 vs 31.6 ± 5.8), baseline heart rate (104.2 ± 11.6 vs 94.0 ± 7.0 bpm), total leisure activity score-Godin (9.3 ± 8.8 vs 41.5 ± 15.2), total screen time (6.9 ± 5.8 vs 3.1 ± 1.4 h/d), and a significant improvement in fitness. Following the placebo drink, both groups achieved a significantly higher peak heart rate (untrained: 176.1 ± 13.7 vs 167.5 ± 16.8; trained: 170.7 ± 11.6 vs 166.2 ± 11.4 bpm) and longer running time (untrained: 559.9 ± 151.0 vs 434.4 ± 140.3 seconds; trained: 728.3 ± 177.3 vs 667.1 ± 176.1 seconds). Despite longer exercise duration and higher peak exercise heart rate, average, and peak RPE were lower after the placebo drink (untrained: 12.1 ± 2.3 vs 13.6 ± 2.1; trained:10.0 ± 1.8 vs 11.6 ± 2.1), recovery time was shorter (untrained: 119.2 ± 25.3 vs 133.2 ± 23.7 seconds; trained: 92.6 ± 18.9 vs 102.7 ± 18.3 seconds). The placebo-induced change in running time and peak RPE were significantly greater prior to training. CONCLUSION: The significant information placebo effect is preserved in trained overweight children. Information, as well as other motivating aids and fatigue distractors may be useful in enhancing physical performance in obese children.

Familiarisation of novice and experienced treadmill users during a running session: Group specific evidence, time and individual patterns.

The elimination of familiarisation effects is a recurring topic in biomechanical testing during treadmill running among different experience levels. The two aims of this study were (i) to calculate familiarisation times of novice and experienced treadmill runners on a group level and (ii) to examine individual familiarisation patterns in order to classify those with similar characteristics. Twenty runners participated in this study by performing a treadmill running session with 3D motion capture. Familiarisation times for 9 kinematic variables among both groups (novices and experienced treadmill runners) were statistically analysed. Additionally a qualitative clustering process (supported by quantitative criteria) provided individual familiarisation patterns for all participants and variables. Group mean familiarisation times were inconsistent across variables (ranging from 3 to 14 min), with no general tendency for decreased familiarisation time in experienced compared to novice treadmill runners. The analysis of individual familiarisation patterns revealed that 30.5% were not stable after 15 min. Substantial changes compared to the initial state were observed in data sets with detected familiarisation pattern. Treadmill running experience does not affect familiarisation patterns since this process is highly individual and variable-specific. Consequently, no generalised familiarisation time can be provided and the elimination of familiarisation in biomechanical testing a priori does not seem to be possible in the first 15 min for approximately one third of the individual patterns studied. In conclusion, the common practice of collecting data subsequent to a pre-defined generalised familiarisation time ought to be replaced by measurements at several points in time during trials. This required procedure would allow for checking familiarisation patterns and fluctuations in order to exclude inappropriate data sets in future treadmill studies.

Effect of an interdisciplinary intervention with motivational approach on exercise capacity in obese adolescents: a randomized controlled clinical trial / Efeito de intervenção interdisciplinar com abordagem motivacional na capacidade de exercício em adolescentes obesos: ensaio clínico controlado randomizado

ABSTRACT Objective To evaluate the effect of an interdisciplinary intervention with a motivational approach on exercise capacity and usual physical activity levels in overweight and obese adolescents. Methods This is a randomized, controlled clinical trial with single blinding of subjects. Adolescents aged 15 to 18 years with overweight and obesity (body mass index ≥ 85 percentile) were included. The adolescents were randomized into two groups: interdisciplinary intervention or control − traditional approach aiming at lifestyle modifications. The initial evaluations were carried out, including the cardiopulmonary exercise test and the physical activity level measurement by using the International Physical Activity Questionnaire and a pedometer. The evaluations were performed in two moments: time zero (time of inclusion in the study) and after 3 months (end of intervention). There were 12 sessions with weekly meetings. Results A total of 37 participants were included, 19 in the Intervention Group. There were no significant differences in the baseline demographic, anthropometric and physical activity characteristics between groups, with mean age of 17.3±1.0 years in the Control Group, and 16.8±0.9 years in the Intervention Group (p=0.14). The motivational intervention did not cause significant differences (p>0.05) in the comparison of the variables of exercise capacity and usual physical activity (questionnaire and pedometer) between groups. Conclusion The intervention with a motivational approach did not alter exercise capacity and levels of usual physical activity in overweight and obese adolescents. Clinical Trial Registry: NCT02455973 and REBEC: RBR-234nb5.

RESUMO Objetivo Avaliar o efeito de uma intervenção interdisciplinar com abordagem motivacional na capacidade de exercício e no nível de atividade física habitual em adolescentes com sobrepeso e obesidade. Métodos Trata-se de ensaio clínico controlado, randomizado, com cegamento único dos indivíduos. Foram incluídos adolescentes com idade entre 15 e 18 anos, com sobrepeso e obesidade (índice de massa corporal ≥ percentil 85). Os adolescentes foram randomizados em dois grupos: intervenção interdisciplinar motivacional ou controle − abordagem tradicional, visando à modificação do estilo de vida. Foram realizadas as avaliações iniciais incluindo o teste de exercício cardiopulmonar e a aferição do nível de atividade física por meio do International Physical Activity Questionnaire e do pedômetro. As avaliações foram realizadas em dois momentos, no tempo zero (inclusão no estudo) e após 3 meses (término da intervenção). Foram realizadas 12 sessões com encontros semanais. Resultados Foram incluídos 37 participantes, sendo 19 no Grupo Intervenção. Não houve diferenças significativas nos dados basais de características demográficas, antropométricas e de atividade física entre os grupos, e a média de idade foi de 17,3±1,0 anos no Grupo Controle e 16,8±0,9 anos no Intervenção (p=0,14). A intervenção motivacional não provocou diferenças significativas (p>0,05) na comparação das variáveis de capacidade de exercício e atividade física habitual (questionário e pedômetro) entre os grupos. Conclusão A intervenção com abordagem motivacional não alterou a capacidade de exercício e os níveis de atividade física habitual em adolescentes com sobrepeso e obesidade. Clinical Trial Registry: NCT02455973 and REBEC: RBR-234nb5.

Accessible exercise equipment and individuals with multiple sclerosis: Aerobic demands and preferences.

BACKGROUND: Although exercise training has benefits for individuals with multiple sclerosis (MS), research regarding the type of exercise equipment that requires the greatest aerobic demand, and consumer-based preferences, is lacking. OBJECTIVE: To determine the aerobic demands of various pieces of accessible exercise equipment and consumer-based preferences on several domains. METHODS: Ten individuals with moderate-severity MS had their VO2 measured during 10 minutes of moderate-intensity arm ergometry (AE), body-weight support treadmill training (BWSTT), recumbent arm-leg exercise (NuStep), FES-arm exercise (RT300), FES-leg exercise (RT300) and FES arm-leg exercise (RT200). VO2peak test was also measured on the NuStep and the RT200. Equipment preferences were determined by questionnaire after moderate exercise sessions. RESULTS: AE required a lower VO2 compared to the NuStep (p = 0.02), and FES-arm exercise required a lower VO2 compared to the NuStep (p = 0.01) and FES arm-leg exercise (p = 0.04). There was no difference in VO2peak when using the NuStep or FES arm-leg exercise. AE was perceived as safer than BWSTT, but otherwise there were no preferences for any equipment. CONCLUSIONS: For individuals with moderate-severity MS, arm-only exercise requires less aerobic demands than combined arm-leg exercise at a moderate intensity. Perceived risks may be greater when exercise requires a transfer, upright positioning, or assistance.

Intensity-Dependent Effects of Acute Exercise on Executive Function.

Numerous studies suggest beneficial effects of aerobic exercise at moderate intensity on cognition, while the effects of high-intensity exercise are less clear. This study investigated the acute effects of exercise at moderate and high intensities on executive functions in healthy adults, including functional MRI to examine the underlying neural mechanisms. Furthermore, the association between exercise effects and cardiorespiratory fitness was examined. 64 participants performed in two executive function tasks (flanker and Go/No-go tasks), while functional MR images were collected, following two conditions: in the exercise condition, they cycled on an ergometer at either moderate or high intensity (each n = 32); in the control condition, they watched a movie. Differences in behavioral performance and brain activation between the two conditions were compared between groups. Further, correlations between cardiorespiratory fitness and exercise effects on neural and behavioral correlates of executive performance were calculated. Moderate exercise compared to high-intensity exercise was associated with a tendency towards improved behavioral performance (sensitivity index d') in the Go/No-go task and increased brain activation during hit trials in areas related to executive function, attention, and motor processes (insula, superior frontal gyrus, precentral gyrus, and supplementary motor area). Exercise at high intensity was associated with decreased brain activation in those areas and no changes in behavioral performance. Exercise had no effect on brain activation in the flanker task, but an explorative analysis revealed that reaction times improved after high-intensity exercise. Higher cardiorespiratory fitness was correlated with increased brain activation after moderate exercise and decreased brain activation after high-intensity exercise. These data show that exercise at moderate vs. high intensity has different effects on executive task performance and related brain activation changes as measured by fMRI and that cardiorespiratory fitness might be a moderating factor of acute exercise effects. Thus, our results may contribute to further clarify the neurophysiological mechanisms underlying the beneficial effects of exercise on cognition.