The effects of physical activity on white matter microstructure in children with overweight or obesity: The ActiveBrains randomized clinical trial / Los efectos de la actividad física sobre la microestructura de la sustancia blanca en niños con sobrepeso u obesidad: el ensayo clínico aleatorizado ActiveBrains

Background: Emerging research supports the idea that physical activity benefits brain development. However, the body of evidence focused on understanding the effects of physical activity on white matter microstructure during childhood is still in its infancy, and further well-designed randomized clinical trials are needed. Aim: This study aimed: (i) to investigate the effects of a 20-week physical activity intervention on global white matter microstructure in children with overweight or obesity, and (ii) to explore whether the effect of physical activity on white matter microstructure is global or restricted to a particular set of white matter bundles. Methods: In total, 109 children aged 8 to 11 years with overweight or obesity were randomized and allocated to either the physical activity program or the control group. Data were collected from November 2014 to June 2016, with diffusion tensor imaging (DTI) data processing and analyses conducted between June 2017 and November 2021. Images were pre-processed using the Functional Magnetic Resonance Imaging (MRI) of the Brain´s Software Library (FSL) and white matter properties were explored by probabilistic fiber tractography and tract-based spatial statistics (TBSS). Results: Intention-to-treat analyses were performed for all children who completed the pre-test and post-test DTI assessment, with good quality DTI data (N = 89). Of them, 83 children (10.06±1.11 years, 39 % girls, intervention group=44) met the per-protocol criteria (attended at least 70 % of the recommended sessions). Our probabilistic fiber tractography analysis did not show any effects in terms of global and tract-specific fractional anisotropy (FA) and mean diffusivity (MD) in the per-protocol or intention-to-treat analyses. Additionally, we did not observe any effects on the voxel-wise DTI parameters (i.e., FA and MD) using the most restricted TBSS approach (i.e., per protocol analyses and p-corrected image with a statistical...(AU)

Associations between muscular strength and mental health in cognitively normal older adults: a cross-sectional study from the AGUEDA trial.

Objective: To examine the associations between muscular strength and mental health. Design: We used baseline data of 91 cognitively healthy older adults (71.69 ± 3.91 years old, 57 % women) participating in the AGUEDA randomized controlled trial. Methods: Muscular strength was assessed using both objective (i.e., handgrip strength, biceps curl, squats, and isokinetic test) and perceived (i.e., International Fitness Scale) indicators. Psychological ill-being indicators: anxiety, depression, stress, and loneliness; and psychological well-being indicators: satisfaction with life, self-esteem, and emotional well-being) were assessed using a set of valid and reliable self-reported questionnaires. Linear regression analyses were performed adjusting for sex, age, years of education, body mass index , alcohol, diet, and smoking (model 1), and additionally by cardiorespiratory fitness (model 2). Results: Elbow extension was positively associated with stress in model 1 (ß = 0.252, 95 % Confidence Interval [95 % CI] = 0.007 to 0.497, p = 0.044), and even after further adjustment for cardiorespiratory fitness (ß = 0.282, 95 % CI = 0.032 to 0.532, p = 0.028). Perceived strength was negatively associated with depressive symptoms in model 1 (ß = -0.271, 95 % CI = -0.491 to -0.049, p = 0.017) and model 2 reported associations tending towards significant (ß = -0.220, 95 % CI = -0.445 to 0.005, p = 0.055). Handgrip strength was positively associated with self-esteem in model 1 (ß = 0.558, 95 % CI = 0.168 to 0.949, p = 0.006) and model 2 (ß = 0.546, 95 % CI = 0.135 to 0.956, p = 0.010). No further associations were found among other muscular strength and mental health variables. Conclusion: Handgrip had a moderate association with self-esteem and there was a small association between perceived strength with depressive symptoms and elbow extension with stress. No other associations were observed between muscular strength and mental health outcomes in cognitively normal older adults.

The "STAR WARS: The First Jedi" Program-Effects of Gamification on Psychological Well-Being of College Students.

Background: College students are particularly susceptible to developing mental health problems. Gamification can be a powerful teaching strategy to favor motivation and behavioral changes for the improvement of psychological well-being. Purpose: To analyze the effect of a 14-week gamification-based physical education teaching program on psychological well-being of college students. Materials and Methods: A total of 112 college students (21.22 ± 2.55 years) were recruited and assigned to a gamification-based group or a control group. The intervention group participated in a gamification-based program under the framework of "STAR WARS" science fiction sage. Participants from this group used a mobile app with a countdown timer and the way for them to gain lifetime was by doing physical activity (PA) and formative challenges. The control group did not experience the gamification approach itself as their classes were based on traditional methodology. They were asked to maintain their usual lifestyle and were not required to do PA. Emotional intelligence, personal initiative, entrepreneurial attitude, resilience, and self-efficacy were self-reported. Results: The gamification-based group showed a significantly higher improvement of emotional intelligence (P ≤ 0.006), personal initiative (P ≤ 0.033), entrepreneurial attitude (P < 0.001), resilience (P = 0.002), and self-efficacy (P < 0.001), compared with the control group. Overall effect sizes were of medium magnitude for emotional intelligence and personal initiative, large magnitude for entrepreneurial attitude, and small magnitude for resilience and self-efficacy. Conclusion: Gamification and the use of mobile apps may become powerful teaching strategies to motivate college students toward healthier lifestyle behaviors that have psychological well-being benefits.

The effects of an exercise intervention on neuroelectric activity and executive function in children with overweight/obesity: The ActiveBrains randomized controlled trial.

OBJECTIVE: To investigate whether a 20-week aerobic and resistance exercise program induces changes in brain current density underlying working memory and inhibitory control in children with overweight/obesity. METHODS: A total of 67 children (10.00 ± 1.10 years) were randomized into an exercise or control group. Electroencephalography (EEG)-based current density (µA/mm2 ) was estimated using standardized low-resolution brain electromagnetic tomography (sLORETA) during a working memory task (Delayed non-matched-to-sample task, DNMS) and inhibitory control task (Modified flanker task, MFT). In DNMS, participants had to memorize four stimuli (Pokemons) and then select between two of them, one of which had not been previously shown. In MFT, participants had to indicate whether the centered cow (i.e., target) of five faced the right or left. RESULTS: The exercise group had significantly greater increases in brain activation in comparison with the control group during the encoding phase of DNMS, particularly during retention of second stimuli in temporal and frontal areas (peak t = from 3.4 to 3.8, cluster size [k] = from 11 to 39), during the retention of the third stimuli in frontal areas (peak t = from 3.7 to 3.9, k = from 15 to 26), and during the retention of the fourth stimuli in temporal and occipital areas (peak t = from 2.7 to 4.3, k = from 13 to 101). In MFT, the exercise group presented a lower current density change in the middle frontal gyrus (peak t = -4.1, k = 5). No significant change was observed between groups for behavioral performance (p ≥ 0.05). CONCLUSION: A 20-week exercise program modulates brain activity which might provide a positive influence on working memory and inhibitory control in children with overweight/obesity.

Effects of exercise on sleep in children with overweight/obesity: a randomized clinical trial.

OBJECTIVE: The objective of this study was to examine the chronic effects of a 20-week exercise training program on device-assessed sleep and sleep-disordered breathing; and to determine whether participating in a session of the exercise program had effects on device-assessed sleep the subsequent night in children with overweight/obesity. METHODS: A randomized clinical trial was conducted from November 2014 to June 2016. A total of 109 children (age 8-11 years) with overweight/obesity were randomized into an exercise training or control group. The exercise program included aerobic and resistance training 3 to 5 days/week. The control group participants continued their usual lifestyle. Device-assessed sleep outcomes were measured using wrist-worn actigraphy at baseline, in the middle of the exercise program (10th week), and at postintervention for seven consecutive days (24 h/day), and sleep-disordered breathing was measured via the Pediatric Sleep Questionnaire. RESULTS: The exercise training program had a statistically significant effect on wake after sleep onset time (-10.8 min/day, -0.5 SDs, p = 0.040). No other chronic or acute effects (i.e., the subsequent night of attending a session of the exercise training program) were observed on the remaining sleep outcomes. CONCLUSIONS: A 20-week exercise training program reduced wake after sleep onset time in children with overweight/obesity. Future randomized trials that include a sample of children with poor sleep health at baseline are needed to better appreciate the role of exercise in sleep health.

The effects of physical activity on white matter microstructure in children with overweight or obesity: The ActiveBrains randomized clinical trial.

Background: Emerging research supports the idea that physical activity benefits brain development. However, the body of evidence focused on understanding the effects of physical activity on white matter microstructure during childhood is still in its infancy, and further well-designed randomized clinical trials are needed. Aim: This study aimed: (i) to investigate the effects of a 20-week physical activity intervention on global white matter microstructure in children with overweight or obesity, and (ii) to explore whether the effect of physical activity on white matter microstructure is global or restricted to a particular set of white matter bundles. Methods: In total, 109 children aged 8 to 11 years with overweight or obesity were randomized and allocated to either the physical activity program or the control group. Data were collected from November 2014 to June 2016, with diffusion tensor imaging (DTI) data processing and analyses conducted between June 2017 and November 2021. Images were pre-processed using the Functional Magnetic Resonance Imaging (MRI) of the Brain´s Software Library (FSL) and white matter properties were explored by probabilistic fiber tractography and tract-based spatial statistics (TBSS). Results: Intention-to-treat analyses were performed for all children who completed the pre-test and post-test DTI assessment, with good quality DTI data (N = 89). Of them, 83 children (10.06±1.11 years, 39 % girls, intervention group=44) met the per-protocol criteria (attended at least 70 % of the recommended sessions). Our probabilistic fiber tractography analysis did not show any effects in terms of global and tract-specific fractional anisotropy (FA) and mean diffusivity (MD) in the per-protocol or intention-to-treat analyses. Additionally, we did not observe any effects on the voxel-wise DTI parameters (i.e., FA and MD) using the most restricted TBSS approach (i.e., per protocol analyses and p-corrected image with a statistical threshold of p < 0.05). In the intention-to-treat analysis, we found that our physical activity program had a borderline effect (p-corrected image with a statistical threshold of p < 0.1) on 7 different clusters, including a cluster in the corpus callosum. Conclusion: We conclude that a 20-week physical activity intervention was not enough to induce changes in global and tract-specific white matter during childhood. The effects of physical activity on white matter microstructure could be restricted to local changes in several white matter tracts (e.g., the body of the corpus callosum). However, our results were not significant, and more interventions are needed to determine whether and how physical activity affects white matter microstructure during childhood.

Cadence (steps/min) and relative intensity in 61 to 85-year-olds: the CADENCE-Adults study.

BACKGROUND: We previously demonstrated that a heuristic (i.e., evidence-based, rounded yet practical) cadence threshold of ≥ 100 steps/min was associated with absolutely-defined moderate intensity physical activity (i.e., ≥ 3 metabolic equivalents [METs]) in older adults 61-85 years of age. Although it was difficult to ascertain achievement of absolutely-defined vigorous (6 METs) intensity, ≥ 130 steps/min was identified as a defensible threshold for this population. However, little evidence exists regarding cadence thresholds and relatively-defined moderate intensity indicators, including ≥ 64% heart rate [HR] maximum [HRmax = 220-age], ≥ 40% HR reserve [HRR = HRmax-HRresting], and ≥ 12 Borg Scale Rating of Perceived Exertion [RPE]; or vigorous intensity indicators including ≥ 77%HRmax, ≥ 60%HRR, and ≥ 14 RPE. PURPOSE: To analyze the relationship between cadence and relatively-defined physical activity intensity and identify relatively-defined moderate and vigorous heuristic cadence thresholds for older adults 61-85 years of age. METHODS: Ninety-seven ostensibly healthy adults (72.7 ± 6.9 years; 49.5% women) completed up to nine 5-min treadmill walking bouts beginning at 0.5 mph (0.8 km/h) and progressing by 0.5 mph speed increments (with 2-min rest between bouts). Directly-observed (and video-recorded) steps were hand-counted, HR was measured using a chest-strapped monitor, and in the final minute of each bout, participants self-reported RPE. Segmented mixed model regression and Receiver Operating Characteristic (ROC) curve analyses identified optimal cadence thresholds associated with relatively-defined moderate (≥ 64%HRmax, ≥ 40%HRR, and ≥ 12 RPE) and vigorous (≥ 77%HRmax, ≥ 60%HRR, and ≥ 14 RPE) intensities. A compromise between the two analytical methods, including Youden's Index (a sum of sensitivity and specificity), positive and negative predictive values, and overall accuracy, yielded final heuristic cadences. RESULTS: Across all relatively-defined moderate intensity indicators, segmented regression models and ROC curve analyses identified optimal cadence thresholds ranging from 105.9 to 112.8 steps/min and 102.0-104.3 steps/min, respectively. Comparable values for vigorous intensity indicators ranged between126.1-132.1 steps/min and 106.7-116.0 steps/min, respectively. Regardless of the relatively-defined intensity indicator, the overall best heuristic cadence threshold aligned with moderate intensity was ≥ 105 steps/min. Vigorous intensity varied between ≥ 115 (greater sensitivity) or ≥ 120 (greater specificity) steps/min. CONCLUSIONS: Heuristic cadence thresholds align with relatively-defined intensity indicators and can be useful for studying and prescribing older adults' physiological response to, and/or perceived experience of, ambulatory physical activity. TRIAL REGISTRATION: Clinicaltrials.gov NCT02650258. Registered 24 December 2015.

Gene-exercise interaction on brain health in children with overweight/obesity: the ActiveBrains randomized controlled trial.

We investigated the interaction between a genetic score and an exercise intervention on brain health in children with overweight/obesity. One hundred one children with overweight/obesity (10.0 ± 1.5 yr, 59% girls) were randomized into a 20-wk combined exercise intervention or a control group. Several cognitive and academic outcomes were measured with validated tests. Hippocampal volume was quantified using magnetic resonance imaging. Six brain health-related polymorphisms [rs6265 (BDNF), rs2253206 (CREB1), rs2289656 (NTRK2), rs4680 (COMT), rs429358, and rs7412 (APOE)] were genotyped. Cognitive flexibility and academic skills improved significantly more in the exercise than in the control group only in the children with a "favorable" genetic profile [mean z-score, 0.41-0.67 (95% CI 0.11 to 1.18)], yet not in those with "less favorable" genetic profile. An individual response analysis showed that children responded to exercise in cognitive flexibility only in the "genetically favorable" group [i.e., 62% of them had a meaningful (≥0.2 Cohen d) increase in the exercise group compared with only 25% in the control group]. This finding was consistent in per-protocol and intention-to-treat analyses (P = 0.01 and P = 0.03, respectively). The results were not significant or not consistent for the rest of outcomes studied. Our findings suggest that having a more favorable genetic profile makes children with overweight/obesity more responsive to exercise, particularly for cognitive flexibility.NEW & NOTEWORTHY Interindividual differences have been reported in brain health-related outcomes in response to exercise interventions in adults, which could be partially explained by genetic background differences. However, the role of genetic polymorphisms on brain health-related outcomes in response to exercise interventions remains unexplored in pediatric population. The current study in children with overweight/obesity showed that a genetic score composed of six brain health-related polymorphisms (BDNF, CREB1, NTRK2, COMT, and APOE) regulated the exercise-induced response on several brain health outcomes, yet mainly and more consistently on cognitive flexibility.

Active Gains in brain Using Exercise During Aging (AGUEDA): protocol for a randomized controlled trial.

Alzheimer's disease is currently the leading cause of dementia and one of the most expensive, lethal and severe diseases worldwide. Age-related decline in executive function is widespread and plays a key role in subsequent dementia risk. Physical exercise has been proposed as one of the leading non-pharmaceutical approaches to improve executive function and ameliorate cognitive decline. This single-site, two-arm, single-blinded, randomized controlled trial (RCT) will include 90 cognitively normal older adults, aged 65-80 years old. Participants will be randomized to a 24-week resistance exercise program (3 sessions/week, 60 min/session, n = 45), or a wait-list control group (n = 45) which will be asked to maintain their usual lifestyle. All study outcomes will be assessed at baseline and at 24-weeks after the exercise program, with a subset of selected outcomes assessed at 12-weeks. The primary outcome will be indicated by the change in an executive function composite score assessed with a comprehensive neuropsychological battery and the National Institutes of Health Toolbox Cognition Battery. Secondary outcomes will include changes in brain structure and function and amyloid deposition, other cognitive outcomes, and changes in molecular biomarkers assessed in blood, saliva, and fecal samples, physical function, muscular strength, body composition, mental health, and psychosocial parameters. We expect that the resistance exercise program will have positive effects on executive function and related brain structure and function, and will help to understand the molecular, structural, functional, and psychosocial mechanisms involved.

Cadence-based classification of moderate-intensity overground walking in 41- to 85-year-old adults.

BACKGROUND: Walking cadence (steps/min) has emerged as a valid proxy of physical activity intensity, with consensus across numerous laboratory-based treadmill studies that ≥100 steps/min approximates absolutely defined moderate intensity (≥3 metabolic equivalents; METs). We recently reported that this cadence threshold had a classification accuracy of 73.3% for identifying moderate intensity during preferred pace overground walking in young adults. The purpose of this study was to evaluate and compare the performance of a cadence threshold of ≥100 steps/min for correctly classifying moderate intensity during overground walking in middle- and older-aged adults. METHODS: Participants (N = 174, 48.3% female, 41-85 years of age) completed laboratory-based cross-sectional study involving an indoor 5-min overground walking trial at their preferred pace. Steps were manually counted and converted to cadence (total steps/5 min). Intensity was measured using indirect calorimetry and expressed as METs. Classification accuracy (sensitivity, specificity, accuracy) of a cadence threshold of ≥100 steps/min to identify individuals walking at ≥3 METs was calculated. RESULTS: The ≥100 steps/min threshold demonstrated accuracy of 74.7% for classifying moderate intensity. When comparing middle- vs. older-aged adults, similar accuracy (73.4% vs. 75.8%, respectively) and specificity (33.3% vs. 34.5%) were observed. Sensitivity was high, but was lower for middle- vs. older-aged adults (85.2% vs. 93.9%, respectively). CONCLUSION: A cadence threshold of ≥100 steps/min accurately identified moderate-intensity overground walking. Furthermore, accuracy was similar when comparing middle- and older-aged adults. These findings extend our previous analysis in younger adults and confirm the appropriateness of applying this cadence threshold across the adult lifespan.

Early life factors and hippocampal functional connectivity in children with overweight/obesity.

OBJECTIVE: We investigated the association of anthropometric neonatal data (birth length and birth weight) and breastfeeding practices (exclusive and any breastfeeding) with hippocampal functional connectivity and its academic implication in children with overweight/obesity. METHODS: Ninety six children with overweight/obesity aged 8-11 years (10.01 ± 1.14), from the ActiveBrains project were included in this cross-sectional study. Anthropometric neonatal data were collected from birth records, whereas breastfeeding practices were reported by parents. A 3.0 Tesla Siemens Magnetom Tim Trio system was used to acquire T1-weighted and resting-state functional magnetic resonance images. Academic performance was assessed by the Woodcock-Muñoz standardized test. Hippocampal seed-based methods with post-hoc regression analyses were performed. Analyses were considered significant when surpassing Family-Wise Error corrections. RESULTS: Birth weight showed a positive association with the connectivity between the hippocampus and the pre- and postcentral gyri, and the cerebellum. In addition, breastfeeding was negatively associated with the connectivity between the hippocampus and the primary motor cortex and the angular gyrus. Any breastfeeding, in turn, showed a positive association with the connectivity between the hippocampus and the middle temporal gyrus. None of the connectivity outcomes related to early life factors was coupled with better academic abilities (all p > 0.05). CONCLUSIONS: Our findings suggest that birth weight at birth and breastfeeding are associated with hippocampal connectivity in children with overweight/obesity. Despite this, how the results relate to academic performance remains a matter of speculation. Our findings suggest that clinicians should recognize the importance early life factors for potentially avoiding consequences on offspring's brain development.

Neurotrophic factors and brain health in children with overweight and obesity: The role of cardiorespiratory fitness.

ABSTRACTNeurotrophic factors and cardiorespiratory fitness are both considered important in developmental trajectories but their link to brain health remains poorly understood. The aims of the study were to examine whether levels of plasma-derived neurotrophic factors were associated with brain health indicators in children with overweight or obesity; and to test whether these associations were moderated by cardiorespiratory fitness. 100 children (41% girls) were included in this analysis. Plasma levels of brain-derived neurotrophic factor, insulin-like growth factor-1, vascular endothelial growth factor A, and epidermal growth factor were determined by XMap technology. Academic performance and executive function were assessed using validated neuropsychological tests. Hippocampal volume was measured using magnetic resonance imaging. Cardiorespiratory fitness was assessed using the 20-m Shuttle Run Test. Insulin-like growth factor-1 was positively associated with cognitive flexibility. Stratified analyses by fitness categories (i.e. unfit vs. fit) showed that brain-derived neurotrophic factor was positively associated with right posterior hippocampal volume in fit children, and epidermal growth factor was negatively associated with right hippocampal, and right anterior hippocampal volumes in their unfit peers, with a moderating role of cardiorespiratory fitness in these associations. However, all these significant associations disappeared after correction for multiple comparisons. The association between neurotrophic factors and brain health indicators in children with overweight/obesity was neither strong nor consistent. These results could help enhance our understanding of determinants of brain health in children with overweight/obesity.HighlightsThis study provides novel findings on the associations between neurotrophic factors and a wide range of brain health indicators in children.This study additionally explored the role of cardiorespiratory fitness in these associations.The association between neurotrophic factors and brain health in children with overweight/obesity was neither strong nor consistent.Cardiorespiratory fitness moderated the associations of brain-derived neurotrophic factor and epidermal growth factor with right hippocampal volume.

A catalog of validity indices for step counting wearable technologies during treadmill walking: the CADENCE-adults study.

BACKGROUND: Standardized validation indices (i.e., accuracy, bias, and precision) provide a comprehensive comparison of step counting wearable technologies. PURPOSE: To expand a previously published child/youth catalog of validity indices to include adults (21-40, 41-60 and 61-85 years of age) assessed across a range of treadmill speeds (slow [0.8-3.2 km/h], normal [4.0-6.4 km/h], fast [7.2-8.0 km/h]) and device wear locations (ankle, thigh, waist, and wrist). METHODS: Two hundred fifty-eight adults (52.5 ± 18.7 years, 49.6% female) participated in this laboratory-based study and performed a series of 5-min treadmill bouts while wearing multiple devices; 21 devices in total were evaluated over the course of this multi-year cross-sectional study (2015-2019). The criterion measure was directly observed steps. Computed validity indices included accuracy (mean absolute percentage error, MAPE), bias (mean percentage error, MPE), and precision (correlation coefficient, r; standard deviation, SD; coefficient of variation, CoV). RESULTS: Over the range of normal speeds, 15 devices (Actical, waist-worn ActiGraph GT9X, activPAL, Apple Watch Series 1, Fitbit Ionic, Fitbit One, Fitbit Zip, Garmin vivoactive 3, Garmin vivofit 3, waist-worn GENEActiv, NL-1000, PiezoRx, Samsung Gear Fit2, Samsung Gear Fit2 Pro, and StepWatch) performed at < 5% MAPE. The wrist-worn ActiGraph GT9X displayed the worst accuracy across normal speeds (MAPE = 52%). On average, accuracy was compromised across slow walking speeds for all wearable technologies (MAPE = 40%) while all performed best across normal speeds (MAPE = 7%). When analyzing the data by wear locations, the ankle and thigh demonstrated the best accuracy (both MAPE = 1%), followed by the waist (3%) and the wrist (15%) across normal speeds. There were significant effects of speed, wear location, and age group on accuracy and bias (both p < 0.001) and precision (p ≤ 0.045). CONCLUSIONS: Standardized validation indices cataloged by speed, wear location, and age group across the adult lifespan facilitate selecting, evaluating, or comparing performance of step counting wearable technologies. Speed, wear location, and age displayed a significant effect on accuracy, bias, and precision. Overall, reduced performance was associated with very slow walking speeds (0.8 to 3.2 km/h). Ankle- and thigh-located devices logged the highest accuracy, while those located at the wrist reported the worst accuracy. TRIAL REGISTRATION: Clinicaltrials.gov NCT02650258. Registered 24 December 2015.

Effects of an Exercise Program on Brain Health Outcomes for Children With Overweight or Obesity: The ActiveBrains Randomized Clinical Trial.

Importance: Pediatric overweight and obesity are highly prevalent across the world, with implications for poorer cognitive and brain health. Exercise might potentially attenuate these adverse consequences. Objectives: To investigate the effects of an exercise program on brain health indicators, including intelligence, executive function, academic performance, and brain outcomes, among children with overweight or obesity and to explore potential mediators and moderators of the main effects of exercise. Design, Setting, and Participants: All preexercise and postexercise data for this 20-week randomized clinical trial of 109 children aged 8 to 11 years with overweight or obesity were collected from November 21, 2014, to June 30, 2016, with neuroimaging data processing and analyses conducted between June 1, 2017, and December 20, 2021. All 109 children were included in the intention-to-treat analyses; 90 children (82.6%) completed the postexercise evaluation and attended 70% or more of the recommended exercise sessions and were included in per-protocol analyses. Interventions: All participants received lifestyle recommendations. The control group continued their usual routines, whereas the exercise group attended a minimum of 3 supervised 90-minute sessions per week in an out-of-school setting. Main Outcomes and Measures: Intelligence, executive function (cognitive flexibility, inhibition, and working memory), and academic performance were assessed with standardized tests, and hippocampal volume was measured with magnetic resonance imaging. Results: The 109 participants included 45 girls (41.3%); participants had a mean (SD) body mass index of 26.8 (3.6) and a mean (SD) age of 10.0 (1.1) years at baseline. In per-protocol analyses, the exercise intervention improved crystallized intelligence, with the exercise group improving from before exercise to after exercise (mean z score, 0.62 [95% CI, 0.44-0.80]) compared with the control group (mean z score, -0.10 [95% CI, -0.28 to 0.09]; difference between groups, 0.72 SDs [95% CI, 0.46-0.97]; P < .001). Total intelligence also improved significantly more in the exercise group (mean z score, 0.69 [95% CI, 0.48-0.89]) than in the control group (mean z score, 0.07 [95% CI, -0.14 to 0.28]; difference between groups, 0.62 SDs [95% CI, 0.31-0.91]; P < .001). Exercise also positively affected a composite score of cognitive flexibility (mean z score: exercise group, 0.25 [95% CI, 0.05-0.44]; control group, -0.17 [95% CI, -0.39 to 0.04]; difference between groups, 0.42 SDs [95% CI, 0.13-0.71]; P = .005). These main effects were consistent in intention-to-treat analyses and after multiple-testing correction. There was a positive, small-magnitude effect of exercise on total academic performance (mean z score: exercise group, 0.31 [95% CI, 0.18-0.44]; control group, 0.10 [95% CI, -0.04 to 0.24]; difference between groups, 0.21 SDs [95% CI, 0.01-0.40]; P = .03), which was partially mediated by cognitive flexibility. Inhibition, working memory, hippocampal volume, and other brain magnetic resonance imaging outcomes studied were not affected by the exercise program. The intervention increased cardiorespiratory fitness performance as indicated by longer treadmill time to exhaustion (mean z score: exercise group, 0.54 [95% CI, 0.27-0.82]; control group, 0.13 [95% CI, -0.16 to 0.41]; difference between groups, 0.42 SDs [95% CI, 0.01-0.82]; P = .04), and these changes in fitness mediated some of the effects (small percentage of mediation [approximately 10%-20%]). The effects of exercise were overall consistent across the moderators tested, except for larger improvements in intelligence among boys compared with girls. Conclusions and Relevance: In this randomized clinical trial, exercise positively affected intelligence and cognitive flexibility during development among children with overweight or obesity. However, the structural and functional brain changes responsible for these improvements were not identified. Trial Registration: ClinicalTrials.gov Identifier: NCT02295072.

"STAR WARS: The first Jedi" Gamification Program: Use of a Mobile App to Improve Body Composition in College Students.

Background: There is a need to promote initiatives toward reaching more active and healthier lifestyles. Gamification has emerged among teachers as a powerful teaching strategy that favors students' motivation and behavioral change by applying game elements in nongame contexts. Purpose: To examine the effects of a 14-week gamification-based teaching program, including the use of a game-based mobile app on body composition in college students. Materials and Methods: One hundred twelve college students (21.22 ± 2.55 years) were assigned to a gamification-based group or a control group. College students from the intervention group participated in a gamification program under the narrative of "STAR WARS" and had a mobile app with a countdown timer. They had to meet physical activity recommendations to gain lifetime (i.e., sum time to the countdown). A portable eight-polar bioelectrical impedance analysis was used to obtain body composition outcomes; height (cm) was measured with a stadiometer; and waist circumference (cm) was measured using a metric tape. Body mass index (BMI), muscle mass index, fat mass index, and body fat percentage were computed. Results: Participants from the gamification program reported a significantly lower BMI, waist circumference, fat mass index and body fat percentage after the intervention, in comparison with the control group, indicated by an effect size ranging from -0.23 to -0.11 (all P ≤ 0.043). Conclusion: Gamification and the use of interactive mobile app are powerful teaching strategies in higher education to motivate students toward healthier lifestyles that lead to body composition benefits.

Walking cadence (steps/min) and intensity in 61-85-year-old adults: the CADENCE-Adults study.

BACKGROUND: Heuristic (i.e., evidence-based, rounded) cadences of ≥100 and ≥ 130 steps/min have consistently corresponded with absolutely-defined moderate (3 metabolic equivalents [METs]) and vigorous (6 METs) physical activity intensity, respectively, in adults 21-60 years of age. There is no consensus regarding similar thresholds in older adults. PURPOSE: To provide heuristic cadence thresholds for 3, 4, 5, and 6 METs in 61-85-year-old adults. METHODS: Ninety-eight community-dwelling ambulatory and ostensibly healthy older adults (age = 72.6 ± 6.9 years; 49% women) walked on a treadmill for a series of 5-min bouts (beginning at 0.5 mph with 0.5 mph increments) in this laboratory-based cross-sectional study until: 1) transitioning to running, 2) reaching ≥75% of their age-predicted maximum heart rate, or 3) reporting a Borg rating of perceived exertion > 13. Cadence was directly observed and hand-tallied. Intensity (oxygen uptake [VO2] mL/kg/min) was assessed with indirect calorimetry and converted to METs (1 MET = 3.5 mL/kg/min). Cadence thresholds were identified via segmented mixed effects model regression and using Receiver Operating Characteristic (ROC) curves. Final heuristic cadence thresholds represented an analytical compromise based on classification accuracy (sensitivity, specificity, positive and negative predictive value, and overall accuracy). RESULTS: Cadences of 103.1 (95% Prediction Interval: 70.0-114.2), 116.4 (105.3-127.4), 129.6 (118.6-140.7), and 142.9 steps/min (131.8-148.4) were identified for 3, 4, 5, and 6 METs, respectively, based on the segmented regression. Comparable values based on ROC analysis were 100.3 (95% Confidence Intervals: 95.7-103.1), 111.5 (106.1-112.9), 116.0 (112.4-120.2), and 128.6 steps/min (128.3-136.4). Heuristic cadence thresholds of 100, 110, and 120 were associated with 3, 4, and 5 METs. Data to inform a threshold for ≥6 METs was limited, as only 6/98 (6.0%) participants achieved this intensity. CONCLUSIONS: Consistent with previous data collected from 21-40 and 41-60-year-old adults, heuristic cadence thresholds of 100, 110, and 120 steps/min were associated with 3, 4, and 5 METs, respectively, in 61-85-year-old adults. Most older adults tested did not achieve the intensity of ≥6 METs; therefore, our data do not support establishing thresholds corresponding with this intensity level. TRIAL REGISTRATION: Clinicaltrials.gov NCT02650258 . Registered 24 December 2015.

A catalog of validity indices for step counting wearable technologies during treadmill walking: the CADENCE-Kids study.

BACKGROUND: Wearable technologies play an important role in measuring physical activity (PA) and promoting health. Standardized validation indices (i.e., accuracy, bias, and precision) compare performance of step counting wearable technologies in young people. PURPOSE: To produce a catalog of validity indices for step counting wearable technologies assessed during different treadmill speeds (slow [0.8-3.2 km/h], normal [4.0-6.4 km/h], fast [7.2-8.0 km/h]), wear locations (waist, wrist/arm, thigh, and ankle), and age groups (children, 6-12 years; adolescents, 13-17 years; young adults, 18-20 years). METHODS: One hundred seventeen individuals (13.1 ± 4.2 years, 50.4% female) participated in this cross-sectional study and completed 5-min treadmill bouts (0.8 km/h to 8.0 km/h) while wearing eight devices (Waist: Actical, ActiGraph GT3X+, NL-1000, SW-200; Wrist: ActiGraph GT3X+; Arm: SenseWear; Thigh: activPAL; Ankle: StepWatch). Directly observed steps served as the criterion measure. Accuracy (mean absolute percentage error, MAPE), bias (mean percentage error, MPE), and precision (correlation coefficient, r; standard deviation, SD; coefficient of variation, CoV) were computed. RESULTS: Five of the eight tested wearable technologies (i.e., Actical, waist-worn ActiGraph GT3X+, activPAL, StepWatch, and SW-200) performed at < 5% MAPE over the range of normal speeds. More generally, waist (MAPE = 4%), thigh (4%) and ankle (5%) locations displayed higher accuracy than the wrist location (23%) at normal speeds. On average, all wearable technologies displayed the lowest accuracy across slow speeds (MAPE = 50.1 ± 35.5%), and the highest accuracy across normal speeds (MAPE = 15.9 ± 21.7%). Speed and wear location had a significant effect on accuracy and bias (P < 0.001), but not on precision (P > 0.05). Age did not have any effect (P > 0.05). CONCLUSIONS: Standardized validation indices focused on accuracy, bias, and precision were cataloged by speed, wear location, and age group to serve as important reference points when selecting and/or evaluating device performance in young people moving forward. Reduced performance can be expected at very slow walking speeds (0.8 to 3.2 km/h) for all devices. Ankle-worn and thigh-worn devices demonstrated the highest accuracy. Speed and wear location had a significant effect on accuracy and bias, but not precision. TRIAL REGISTRATION: Clinicaltrials.gov NCT01989104 . Registered November 14, 2013.

Cadence (steps/min) and relative intensity in 21 to 60-year-olds: the CADENCE-adults study.

BACKGROUND: Heuristic cadence (steps/min) thresholds of ≥100 and ≥ 130 steps/min correspond with absolutely-defined moderate (3 metabolic equivalents [METs]; 1 MET = 3.5 mL O2·kg- 1·min- 1) and vigorous (6 METs) intensity, respectively. Scarce evidence informs cadence thresholds for relatively-defined moderate (≥ 64% heart rate maximum [HRmax = 220-age], ≥ 40%HR reserve [HRR = HRmax -HRresting, and ≥ 12 Rating of Perceived Exertion [RPE]); or vigorous intensity (≥ 77%HRmax, ≥ 60%HRR, and ≥ 14 RPE). PURPOSE: To identify heuristic cadence thresholds corresponding with relatively-defined moderate and vigorous intensity in 21-60-year-olds. METHODS: In this cross-sectional study, 157 adults (40.4 ± 11.5 years; 50.6% men) completed up to twelve 5-min treadmill bouts, beginning at 0.5 mph and increasing by 0.5 mph. Steps were directly observed, HR was measured with chest-worn monitors, and RPE was queried in the final minute of each bout. Segmented mixed model regression and Receiver Operating Characteristic (ROC) curve analyses identified optimal cadence thresholds, stratified by age (21-30, 31-40, 41-50, and 51-60 years). Reconciliation of the two analytical models, including trade-offs between sensitivity, specificity, positive and negative predictive values, and overall accuracy, yielded final heuristic cadences. RESULTS: Across all moderate intensity indicators, the segmented regression models estimated optimal cadence thresholds ranging from 123.8-127.5 (ages 21-30), 121.3-126.0 (ages 31-40), 117.7-122.7 (ages 41-50), and 113.3-116.1 steps/min (ages 51-60). Corresponding values for vigorous intensity were 140.3-144.1, 140.2-142.6, 139.3-143.6, and 131.6-132.8 steps/min, respectively. ROC analysis estimated chronologically-arranged age groups' cadence thresholds ranging from 114.5-118, 113.5-114.5, 104.6-112.9, and 103.6-106.0 across all moderate intensity indicators, and 127.5, 121.5, 117.2-123.2, and 113.0 steps/min, respectively, for vigorous intensity. CONCLUSIONS: Heuristic cadence thresholds corresponding to relatively-defined moderate intensity for the chronologically-arranged age groups were ≥ 120, 120, 115, and 105 steps/min, regardless of the intensity indicator (i.e., % HRmax, %HRR, or RPE). Corresponding heuristic values for vigorous intensity indicators were ≥ 135, 130, 125, and 120 steps/min. These cadences are useful for predicting/programming intensity aligned with age-associated differences in physiological response to, and perceived experiences of, moderate and/or vigorous intensity. TRIAL REGISTRATION: Clinicaltrials.gov NCT02650258 . Registered 24 December 2015.