Associations of "Weekend Warrior" Physical Activity With Incident Disease and Cardiometabolic Health.

BACKGROUND: Achievement of guideline-recommended levels of physical activity (≥150 minutes of moderate-to-vigorous physical activity per week) is associated with lower risk of adverse cardiovascular events and represents an important public health priority. Although physical activity commonly follows a "weekend warrior" pattern, in which most moderate-to-vigorous physical activity is concentrated in 1 or 2 days rather than spread more evenly across the week (regular), the effects of physical activity pattern across a range of incident diseases, including cardiometabolic conditions, are unknown. METHODS: We tested associations between physical activity pattern and incidence of 678 conditions in 89 573 participants (62±8 years of age; 56% women) of the UK Biobank prospective cohort study who wore an accelerometer for 1 week between June 2013 and December 2015. Models were adjusted for multiple baseline clinical factors, and P value thresholds were corrected for multiplicity. RESULTS: When compared to inactive (<150 minutes moderate-to-vigorous physical activity/week), both weekend warrior (267 total associations; 264 [99%] with lower disease risk; hazard ratio [HR] range, 0.35-0.89) and regular activity (209 associations; 205 [98%] with lower disease risk; HR range, 0.41-0.88) were broadly associated with lower risk of incident disease. The strongest associations were observed for cardiometabolic conditions such as incident hypertension (weekend warrior: HR, 0.77 [95% CI, 0.73-0.80]; P=1.2×10-27; regular: HR, 0.72 [95% CI, 0.68-0.77]; P=4.5×10-28), diabetes (weekend warrior: HR, 0.57 [95% CI, 0.51-0.62]; P=3.9×10-32; regular: HR, 0.54 [95% CI, 0.48-0.60]; P=8.7×10-26), obesity (weekend warrior: HR, 0.55 [95% CI, 0.50-0.60]; P=2.4×10-43, regular: HR, 0.44 [95% CI, 0.40-0.50]; P=9.6×10-47), and sleep apnea (weekend warrior: HR, 0.57 [95% CI, 0.48-0.69]; P=1.6×10-9; regular: HR, 0.49 [95% CI, 0.39-0.62]; P=7.4×10-10). When weekend warrior and regular activity were compared directly, there were no conditions for which effects differed significantly. Observations were similar when activity was thresholded at the sample median (≥230.4 minutes of moderate-to-vigorous physical activity/week). CONCLUSIONS: Achievement of measured physical activity volumes consistent with guideline recommendations is associated with lower risk for >200 diseases, with prominent effects on cardiometabolic conditions. Associations appear similar whether physical activity follows a weekend warrior pattern or is spread more evenly throughout the week.

Diurnal timing of physical activity and risk of colorectal cancer in the UK Biobank.

BACKGROUND: Physical activity reduces colorectal cancer risk, yet the diurnal timing of physical activity in colorectal cancer etiology remains unclear. METHODS: This study used 24-h accelerometry time series from UK Biobank participants aged 42 to 79 years to derive circadian physical activity patterns using functional principal component analysis. Multivariable Cox proportional hazard models were used to examine associations with colorectal cancer risk. RESULTS: Among 86,252 participants (56% women), 529 colorectal cancer cases occurred during a median 5.3-year follow-up. We identified four physical activity patterns that explained almost 100% of the data variability during the day. A pattern of continuous day-long activity was inversely associated with colorectal cancer risk (hazard ratio (HR) = 0.94, 95% confidence interval (CI) = 0.89-0.99). A second pattern of late-day activity was suggestively inversely related to risk (HR = 0.93, 95% CI = 0.85-1.02). A third pattern of early- plus late-day activity was associated with decreased risk (HR = 0.89, 95% CI = 0.80-0.99). A fourth pattern of mid-day plus night-time activity showed no relation (HR = 1.02, 95% CI = 0.88-1.19). Our results were consistent across various sensitivity analyses, including the restriction to never smokers, the exclusion of the first 2 years of follow-up, and the adjustment for shift work. CONCLUSIONS: A pattern of early- plus late-day activity is related to reduced colorectal cancer risk, beyond the benefits of overall activity. Further research is needed to confirm the role of activity timing in colorectal cancer prevention.

Evaluation of mobility recovery after hip fracture: a scoping review of randomized controlled studies.

Few older adults regain their pre-fracture mobility after a hip fracture. Intervention studies evaluating effects on gait typically use short clinical tests or in-lab parameters that are often limited to gait speed only. Measurements of mobility in daily life settings exist and should be considered to a greater extent than today. Less than half of hip fracture patients regain their pre-fracture mobility. Mobility recovery is closely linked to health status and quality of life, but there is no comprehensive overview of how gait has been evaluated in intervention studies on hip fracture patients. The purpose was to identify what gait parameters have been used in randomized controlled trials to assess intervention effects on older people's mobility recovery after hip fracture. This scoping review is a secondary paper that identified relevant peer-reviewed and grey literature from 11 databases. After abstract and full-text screening, 24 papers from the original review and 8 from an updated search and manual screening were included. Records were eligible if they included gait parameters in RCTs on hip fracture patients. We included 32 papers from 29 trials (2754 unique participants). Gait parameters were primary endpoint in six studies only. Gait was predominantly evaluated as short walking, with gait speed being most frequently studied. Only five studies reported gait parameters from wearable sensors. Evidence on mobility improvement after interventions in hip fracture patients is largely limited to gait speed as assessed in a controlled setting. The transition from traditional clinical and in-lab to out-of-lab gait assessment is needed to assess effects of interventions on mobility recovery after hip fracture at higher granularity in all aspects of patients' lives, so that optimal care pathways can be defined.

Spatiotemporal Gait Analysis of Patients with Spinocerebellar Ataxia Types 3 and 10 Using Inertial Measurement Units: A Comparative Study.

Given the high morbidity related to the progression of gait deficits in spinocerebellar ataxias (SCA), there is a growing interest in identifying biomarkers that can guide early diagnosis and rehabilitation. Spatiotemporal parameter (STP) gait analysis using inertial measurement units (IMUs) has been increasingly studied in this context. This study evaluated STP profiles in SCA types 3 and 10, compared them to controls, and correlated them with clinical scales. IMU portable sensors were used to measure STPs under four gait conditions: self-selected pace (SSP), fast pace (FP), fast pace checking-boxes (FPCB), and fast pace with serial seven subtractions (FPS7). Compared to healthy subjects, both SCA groups had higher values for step time, variability, and swing time, with lower values for gait speed, cadence, and step length. We also found a reduction in speed gain capacity in both SCA groups compared to controls and an increase in speed dual-task cost in the SCA10 group. However, there were no significant differences between the SCA groups. Swing time, mean speed, and step length were correlated with disease severity, risk of falling and functionality in both clinical groups. In the SCA3 group, fear of falling was correlated with cadence. In the SCA10 group, results of the Montreal cognitive assessment test were correlated with step time, mean speed, and step length. These results show that individuals with SCA3 and SCA10 present a highly variable, short-stepped, slow gait pattern compared to healthy subjects, and their gait quality worsened with a fast pace and dual-task involvement.

Time-energy budgets outperform dynamic body acceleration in predicting daily energy expenditure in kittiwakes, and estimate a very low cost of gliding flight relative to flapping flight.

Energy is a common currency for any living organism, yet estimating energy expenditure in wild animals is challenging. Accelerometers are commonly used to estimate energy expenditure, via a dynamic body acceleration (DBA) or time-energy budget approach. The dynamic body acceleration approach estimates energy expenditure directly from acceleration but may lead to erroneous estimates during inactivity when acceleration is zero but energy expenditure is not. The time-energy budget approach uses accelerometers and other data streams to assign a behaviour to each time step, and then calculates energy expenditure based on activity-specific metabolic rates assigned to each behaviour. Here, used GPS-accelerometry in breeding black-legged kittiwakes (Rissa tridactyla, n=80) to calculate DBA and time-energy budgets derived from simple biologging metrics (speed, wing beat frequency, GPS position). We then compared these two approaches to estimates of energy expenditure from doubly-labelled water. Energy expenditure estimated from DLW correlated with DBA, but the best model to estimate energy expenditure was based on time-energy budgets. Energy costs of flapping flight were higher than all other kittiwake behaviours (5.54 x basal metabolic rate, BMR). Energetic costs of gliding flight (0.80 x BMR) were the lowest of all behaviours, and equivalent to the cost of resting at the colony. DEE for our birds estimated from our calibration coefficients are similar to DEE for our birds estimated with the model coefficient published using different methods. We conclude that once calibrated with DLW, GPS-accelerometry provides a simple method for measuring energy expenditure in wild kittiwakes based on time-energy budgets.

Conservation energetics of beluga whales: using resting and swimming metabolism to understand threats to an endangered population.

The balance between energetic costs and acquisition in free-ranging species is essential for survival, and provides important insights regarding the physiological impact of anthropogenic disturbances on wild animals. For marine mammals such as beluga whales (Delphinapterus leucas), the first step in modeling this bioenergetic balance requires an examination of resting and active metabolic demands. Here, we used open-flow respirometry to measure oxygen consumption during surface rest and submerged swimming by trained beluga whales, and compared these measurements with those of a commonly studied odontocete, the Atlantic bottlenose dolphin (Tursiops truncatus). Both resting metabolic rate (3012±126.0 kJ h-1) and total cost of transport (1.4±0.1 J kg-1 m-1) of beluga whales were consistent with predicted values for moderately sized marine mammals in temperate to cold-water environments, including dolphins measured in the present study. By coupling the rate of oxygen consumption during submerged swimming with locomotor metrics from animal-borne accelerometer tags, we developed predictive relationships for assessing energetic costs from swim speed, stroke rate and partial dynamic acceleration. Combining these energetic data with calculated aerobic dive limits for beluga whales (8.8 min), we found that high-speed responses to disturbance markedly reduce the whale's capacity for prolonged submergence, pushing the cetaceans to costly anaerobic performances that require prolonged recovery periods. Together, these species-specific energetic measurements for beluga whales provide two important metrics, gait-related locomotor costs and aerobic capacity limits, for identifying relative levels of physiological vulnerability to anthropogenic disturbances that have become increasingly pervasive in their Arctic habitats.

Dynamic soaring decouples dynamic body acceleration and energetics in albatrosses.

Estimates of movement costs are essential for understanding energetic and life-history trade-offs. Although overall dynamic body acceleration (ODBA) derived from accelerometer data is widely used as a proxy for energy expenditure (EE) in free-ranging animals, its utility has not been tested in species that predominately use body rotations or exploit environmental energy for movement. We tested a suite of sensor-derived movement metrics as proxies for EE in two species of albatrosses, which routinely use dynamic soaring to extract energy from the wind to reduce movement costs. Birds were fitted with a combined heart-rate, accelerometer, magnetometer and GPS logger, and relationships between movement metrics and heart rate-derived V̇O2, an indirect measure of EE, were analyzed during different flight and activity modes. When birds were exclusively soaring, a metric derived from angular velocity on the yaw axis provided a useful proxy of EE. Thus, body rotations involved in dynamic soaring have clear energetic costs, albeit considerably lower than those of the muscle contractions required for flapping flight. We found that ODBA was not a useful proxy for EE in albatrosses when birds were exclusively soaring. As albatrosses spend much of their foraging trips soaring, ODBA alone was a poor predictor of EE in albatrosses. Despite the lower percentage of time flapping, the number of flaps was a useful metric when comparing EE across foraging trips. Our findings highlight that alternative metrics, beyond ODBA, may be required to estimate energy expenditure from inertial sensors in animals whose movements involve extensive body rotations.

Associations of light exposure patterns with sleep among Dutch children: The ABCD cohort study.

Light exposure affects the circadian system and consequently can affect sleep quality. Only few studies examined this relationship in children. We evaluated associations between light exposure patterns and sleep metrics in children. We measured the sleep parameters of 247 Dutch children, aged between 11 and 13 years and recruited from the ABCD cohort, using actigraphy and sleep records for 7 consecutive nights. Personal light exposures were measured with a light meter during the whole day and night. We applied generalized mixed-effects regression models, adjusted for possible confounders, to evaluate the associations of light exposure patterns on sleep duration, sleep efficiency and sleep-onset delay. In the models mutually adjusted for potential confounders, we found the amount of hours between the first time of bright light in the morning and going to sleep and the duration of bright light to be significantly associated with decreased sleep duration (in min; ß: -2.02 [95% confidence interval: -3.84, -0.25], ß: -8.39 [95% confidence interval: -16.70, -0.07], respectively) and with shorter sleep-onset delay (odds ratio: 0.88 [95% confidence interval: 0.80, 0.97], odds ratio: 0.40 [95% confidence interval: 0.19, 0.87], respectively). Increased light intensities at night were associated with decreased sleep duration (T2 ß: -8.54 [95% confidence interval: -16.88, -0.20], T3 ß: -14.83 [95% confidence interval: -28.04, -1.62]), while increased light intensities before going to bed were associated with prolonged sleep onset (odds ratio: 4.02 [95% confidence interval: 2.09, 7.73]). These findings further suggest that children may be able to influence their sleep quality by influencing the light exposure patterns during day and night.

Scalar-on-function regression: Estimation and inference under complex survey designs.

Increasingly, large, nationally representative health and behavioral surveys conducted under a multistage stratified sampling scheme collect high dimensional data with correlation structured along some domain (eg, wearable sensor data measured continuously and correlated over time, imaging data with spatiotemporal correlation) with the goal of associating these data with health outcomes. Analysis of this sort requires novel methodologic work at the intersection of survey statistics and functional data analysis. Here, we address this crucial gap in the literature by proposing an estimation and inferential framework for generalizable scalar-on-function regression models for data collected under a complex survey design. We propose to: (1) estimate functional regression coefficients using weighted score equations; and (2) perform inference using novel functional balanced repeated replication and survey-weighted bootstrap for multistage survey designs. This is the first frequentist study to discuss the estimation of scalar-on-function regression models in the context of complex survey studies and to assess the validity of various inferential techniques based on re-sampling methods via a comprehensive simulation study. We implement our methods to predict mortality using diurnal activity profiles measured via wearable accelerometers using the National Health and Nutrition Examination Survey 2003-2006 data. The proposed computationally efficient methods are implemented in R software package surveySoFR.

Differences in elementary-age children's accelerometer - measured physical activity between school and summer: three-year findings from the What's UP (Undermining Prevention) with summer observational cohort study.

BACKGROUND: Among elementary-aged children (5-12yrs), summer vacation is associated with accelerated gains in Body Mass Index (BMI). A key behavioral driver of BMI gain is a lack of physical activity (PA). Previous studies indicate PA decreases during summer, compared to the school year but whether this difference is consistent among boys and girls, across age, and by income status remains unclear. This study examined differences in school and summer movement behaviors in a diverse cohort of children across three years. METHODS: Children (N = 1,203, age range 5-14 years, 48% girls) wore wrist-placed accelerometers for a 14-day wear-period during school (April/May) and summer (July) in 2021 to 2023, for a total of 6 timepoints. Mixed-effects models examined changes in school vs. summer movement behaviors (moderate-to-vigorous physical activity [MVPA], sedentary) for boys and girls, separately, and by age and household income groups (low, middle, and upper based on income-to-poverty ratio). RESULTS: Children provided a total of 35,435 valid days of accelerometry. Overall, boys (+ 9.1 min/day, 95CI 8.1 to 10.2) and girls (+ 6.2 min/day, 95CI 5.4 to 7.0) accumulated more MVPA during school compared to summer. Boys accumulated less time sedentary (-9.9 min/day, 95CI -13.0 to -6.9) during school, while there was no difference in sedentary time (-2.7 min/day, 95CI -5.7 to 0.4) for girls. Different patterns emerged across ages and income groups. Accumulation of MVPA was consistently greater during school compared to summer across ages and income groups. Generally, the difference between school and summer widened with increasing age, except for girls from middle-income households. Accumulation of sedentary time was higher during school for younger children (5-9yrs), whereas for older children (10-14yrs), sedentary time was greater during summer for the middle- and upper-income groups. For boys from low-income households and girls from middle-income households, sedentary time was consistently greater during summer compared to school across ages. CONCLUSIONS: Children are less active and more sedentary during summer compared to school, which may contribute to accelerated BMI gain. However, this differs by biological sex, age, and income. These findings highlight the complex factors influencing movement behaviors between school and summer.

Effects of remote coaching following supervised exercise oncology rehabilitation on physical activity levels, physical fitness, and patient-reported outcomes: a randomised controlled trial.

BACKGROUND: Studies have shown that cancer survivors experience difficulties maintaining physical activity levels after participation in a supervised exercise rehabilitation program. This study aimed to assess the effectiveness of a six-month remote coaching intervention, following a supervised exercise oncology rehabilitation program on maintenance of PA levels; and improvement of aerobic capacity, muscle strength and patient-reported outcomes in cancer survivors. METHODS: Ninety-seven participants from a Dutch University Hospital's exercise rehabilitation program were randomised to the COACH group (n = 46), receiving 6 months of remote coaching after completing the exercise program, or the CONTROL group (n = 50), receiving no additional intervention. Assessment of PA levels; sedentary time; aerobic capacity; muscle strength; fatigue; health-related quality of life (HRQoL); level of anxiety and depression; and return to work (RTW) rates were conducted at baseline (T0) and six months later (T1). Multiple linear regression was used for between-group statistical comparisons of all outcomes measures. Mean differences at T1 were estimated with corresponding 95% confidence intervals (95%CI). RESULTS: No significant between-group differences were observed for all outcomes at T1. An adjusted mean difference in weekly PA of 45 min (95%CI -50;140) was observed between the COACH group and the CONTROL group, favouring the COACH group, yet lacking statistical or clinical significance. CONCLUSIONS: Our six-month remote coaching intervention did not notably improve PA levels; sedentary time; aerobic capacity; muscle strength; HRQoL; fatigue; anxiety and depression symptoms and RTW rates after participation in a supervised exercise oncology program. Although the participants who received coaching showed slightly higher levels of PA, these differences were not significant. More research is needed to identify patients in need for follow-up interventions following supervised exercise program and to investigate the effectiveness of remote coaching interventions in these patients. TRIAL REGISTRATION: Dutch Trial Register NL7729, registered 13 may 2019, https://trialsearch.who.int/Trial2.aspx?TrialID=NL7729 .

Social cohesion and associations with sedentary time, physical activity and dietary quality in The Maastricht Study.

INTRO: We aim to investigate the relationship between social cohesion and sedentary behavior (SB), total physical activity (PA), moderate-to-vigorous PA (MVPA), and dietary quality. Additionally, we assess whether these associations are independent of neighborhood walkability and the food environment. METHODS: A total of 7641 participants from The Maastricht Study in the Netherlands between the ages of 40 and 75 years were analyzed. Neighborhood social cohesion was obtained by participant questionnaire completed at baseline and measured by the Dutch Livability meter. Home addresses were linked to geographic information system (GIS) data from the Geoscience and Health Cohort Consortium (GECCO) to create neighborhood exposures of walkability and food environment. A thigh worn accelerometer collected data to measure sedentary time, total daily PA, and MVPA. Dietary quality was measured with a food frequency questionnaire. Multivariate linear regression analyses were adjusted for age, sex, socioeconomic position, neighborhood walkability, and food environment. RESULTS: Those living in the highest quartile area of perceived social cohesion had statistically significant lower levels of SB (Q4 B: -13.04; 95% CI = -20.23, -5.85), higher total PA (Q4 B: 4.39; 95% CI = 1.69, 7.10), and higher MVPA (Q4 B: 2.57; 95% CI = 0.83, 4.31) and better diet quality (Q4 B: 1.12; 95% CI = 0.24, 2.01) compared to the lowest quartile independent of walkability and food environment. Similar results were found using the Livability meter. CONCLUSION: We discovered neighborhood social cohesion as an important obesogenic determinant that should be considered in policymaking to encourage higher levels of PA and higher diet quality.

More allogrooming is followed by higher physiological stress in wild female baboons.

Social bonds increase fitness in a range of mammals. One pathway by which social bonds may increase fitness is by reducing the exposure to physiological stress, i.e. glucocorticoid (GC) hormones, that can be detrimental to health and survival. This is achieved through downregulating hypothalamic-pituitary-adrenal (HPA)-axis activity. Indeed, long-term measures of social (grooming) bonds are often negatively correlated with HPA-axis activity. However, the proximate role of physical touch through allogrooming remains an open question in the sociality-health-fitness debate. Demonstrating the potential anxiolytic benefits of grooming in the wild is hindered by methodological limitations. Here, we match accelerometer-identified grooming in wild female chacma baboons (Papio ursinus) to non-invasive faecal GC metabolite concentrations (fGCs). Consistent with previous work, we found a negative (but statistically non-significant) overall relationship between individual averaged fGCs and grooming rates. However, when time-matching grooming to fGCs, we found that both more giving and receiving grooming were followed by higher fGCs. This upregulation of HPA-axis activity suggests that maintaining social bonds (and its ultimate fitness benefits) may come at a shorter-term physiological cost. This finding sheds new light on a ubiquitous social behaviour typically considered 'relaxing' and suggests that sociopositive contact can trigger physiological stress.

Associations of steps per day and step intensity with the risk of cancer: Findings from the Women's Health Accelerometry Collaboration cohort.

OBJECTIVE: Accumulating more steps/day is associated with a lower risk of cancer mortality and composite cancer outcomes. However, less is known about the relationship of steps/day with the risk of multiple site-specific cancers. METHODS: This study included >22,000 women from the Women's Health Accelerometry Collaboration Cohort (2011-2022), comprised of women from the Women's Health Study and Women's Health Initiative Objective Physical Activity and Cardiovascular Health Study. Steps/day and step intensity were collected with accelerometry. Incident cancer cases and deaths were adjudicated. Stratified Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) of the associations of steps/day and step intensity with incident breast, colon, endometrial, lung, and ovarian cancers, a composite of 13 physical activity-related cancers, total invasive cancer, and fatal cancer. RESULTS: On average, women were 73.4 years old, accumulated 4993 steps/day, and had 7.9 years of follow-up. There were small nonsignificant inverse associations with the risks of colon cancer (HR = 0.94, 95% CI: 0.83, 1.05), endometrial cancer (HR = 0.91, 95% CI: 0.82, 1.01), and fatal cancer (HR = 0.95 95% CI: 0.90, 1.00) per 1000 steps/day. More minutes at ≥40 steps/min and a faster peak 10- and 30-min step cadence were associated with a lower risk of endometrial cancer, but findings were attenuated after adjustment for body mass index and steps/day. CONCLUSIONS: Among women 62-97 years, there were small nonsignificant inverse associations of colon, endometrial, and fatal cancer with more steps/day. Epidemiologic studies with longer follow-up and updated assessments are needed to further explore these associations.

Children's physical activity and sedentary behaviour in before school care: An observational study.

OBJECTIVE: In Australia, less than one quarter of children aged 5-12 years meet national physical activity (PA) guidelines. Before school care operates as part of Out of School Hours Care (OSHC) services and provide opportunities for children to meet their daily PA recommendations. The aim of this study was to explore factors associated with children meeting 15 min of moderate-to-vigorous-intensity physical activity (MVPA) while attending before school care. METHODS: A cross-sectional study was conducted in 25 services in New South Wales, Australia. Each service was visited twice between March and June 2021. Staff behaviours and PA type and context were captured using staff interviews and the validated System for Observing Staff Promotion of Physical Activity and Nutrition (SOSPAN) time sampling tool. Child PA data were collected using Actigraph accelerometers and associations between program practices and child MVPA analysed. RESULTS: PA data were analysed for 654 children who spent an average of 39.2% (±17.6) of their time sedentary; 45.4% (±11.4) in light PA; and 14.9% (±11.7) in MVPA. Only 17% of children (n = 112) reached ≥15 min MVPA, with boys more likely to achieve this. Children were more likely to meet this recommendation in services where staff promoted and engaged in PA; PA equipment was available; children were observed in child-led free play; and a written PA policy existed. CONCLUSIONS: Before school care should be supported to improve physical activity promotion practices by offering staff professional development and guidance on PA policy development and implementation practices.

The relationships between Physical activity and asthma control and Body Mass Index (BMI) in patients with asthma.

OBJECTIVE: Asthma is one of the most common chronic conditions in developed countries. We examined whether physical activity (PA) is related to asthma control and body mass index (BMI) in asthma patients. METHODS: Cross-sectional data collected on PA (ActiGraph GT3X-BT), asthma control (the Asthma Control Questionnaire; ACQ), and BMI were examined in 206 adults (mean[sd] age 47.2[13.8] years; 49.5% had an obese BMI) with clinically diagnosed asthma. Relationships between PA and continuous BMI and asthma control were assessed using linear regression. Differences in PA across obesity (non-obese: <30 Kg/m2/obese: ≥30 Kg/m2) and asthma control categories (controlled: ≤0.75/uncontrolled: >0.75 ACQ score) were also examined. RESULTS: Median (p25, p75) steps counts and peak cadence were 6035 (4248, 8461) steps/day and 123 (115, 133) steps in a minute, respectively. There were nearly 2000 fewer steps/day among those with uncontrolled asthma versus controlled and among those with obese BMI versus nonobese, respectively (both p < 0.05). In regression models adjusted for relevant covariates each 1-unit increase in ACQ score was associated with -686 [95%CI -997, -13] (p ≤ 0.05) average steps/day. The statistical significance of these findings was attenuated (p ≥ 0.05) when BMI was added to the model. However, the point estimate was not reduced (-766 [95%CI -1060, 34]. CONCLUSIONS: Overall step counts were low in this population despite peak cadence values suggesting that most participants could perform moderate intensity activity. Increasing step counts should be considered an important lifestyle intervention goal in obese and non-obese asthma patients with low PA levels.

The application of a single session of capacitive resistive electric transfer 24 h before exercise modifies the accelerometric pattern in standardbred racing trotters.

BACKGROUND: It has been reported that capacitive resistive electric transfer (CRET) increases blood circulation, hemoglobin oxygenation and temperature in muscles. The attributed benefits of these changes have been linked to improved athletic performance, enhanced muscle flexibility and fastening recovery from exercise-induced fatigue. For all of this, the present research aims to investigate whether the application of CRET 24 h before exercise affects the accelerometric pattern in horses during exercise. Six sound Standardbred trotters were subjected to a CRET session of 40 min of duration, applied on both sides of the neck, back and croup, 24 h before a training session. Training sessions consisted of a warming-up (WU) for 6400 m and a training bout (TB) at their maximal training speed for 1600 m. The same protocol was followed for the device off (sham protocol), also applied 24 h before the training session. CRET and sham experiments were separated by one week, the order of application of both was randomly defined for each individual and drivers were blinded for the duration of the experiment. During the training sessions, horses wore an accelerometer fixed at the sternal level. Speed, stride frequency (SF), length (SL), regularity and symmetry and accelerometric activities were measured during WU and TB. RESULTS: CRET increased speed, mediolateral and total accelerometric activities during WU and speed, SL, dorsoventral, longitudinal and total accelerometric activities during TB, but stride regularity and symmetry decreased. CONCLUSION: The application of CRET 24 h before exercise increased speed and accelerometric activities, results that highlight the need to evaluate the interaction between CRET and training in order to develop new methods to limit fatigue. However, the decrease in stride regularity and symmetry after CRET application could be negative effects, which could be attributed to the increased speed.

Calculation and Comparison of Step Guidelines for Preschooler Physical Activity While Indoors.

OBJECTIVES: Preschooler physical activity (PA) is vital for growth and development. The World Health Organization PA guidelines state preschoolers should achieve ≥ 180 min/day of Total PA (TPA) of which ≥ 60 min is moderate-to-vigorous PA (MVPA). A step/day recommendation to match these guidelines may be a more practical metric for caregivers to promote PA. The purpose of our investigation is to improve upon existing step recommendations by creating one for indoor-based activities, acknowledging where preschoolers spend most of their time, and various cut-points for PA. METHODS: In a laboratory study (Aim 1), a validated direct observation protocol was used to quantify preschooler PA intensity while performing indoor activities (n = 35). Actigraph GT3x accelerometers were placed on the waist, wrist, and ankle to measure step count. In a field study (Aim 2), habitual PA of 881 preschoolers (7113 valid days) via waist-worn accelerometers was used to assess the agreement between created guidelines (Aim 1) and other step recommendations with PA guidelines using Receiver Operating Characteristic and Area Under the Curve (ROC-AUC). RESULTS: In the laboratory study, calculated indoor step ranges were 6960-7440 (waist), 7200-8640 (wrist), and 7680-9120 (ankle) to align with existing PA guidance. In the field, the higher step guidelines (> 12 000) achieved very limited agreement, due to few preschoolers achieving this metric. The 6000 step/day guidelines had the highest agreement (AUCs: TPA: 0.637; MVPA: 0.751; TPA + MVPA: 0.761) with PA guideline. CONCLUSIONS: When preschoolers are indoors, 6000 steps may be the minimum for adequate PA.

Validation of Proprietary and Novel Step-counting Algorithms for Individuals Ambulating With a Lower Limb Prosthesis.

OBJECTIVE: To compare the accuracy and reliability of 10 different accelerometer-based step-counting algorithms for individuals with lower limb loss, accounting for different clinical characteristics and real-world activities. DESIGN: Cross-sectional study. SETTING: General community setting (ie, institutional research laboratory and community free-living). PARTICIPANTS: Forty-eight individuals with a lower limb amputation (N=48) wore an ActiGraph (AG) wGT3x-BT accelerometer proximal to the foot of their prosthetic limb during labeled indoor/outdoor activities and community free-living. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Intraclass correlation coefficient (ICC), absolute and root mean square error (RMSE), and Bland Altman plots were used to compare true (manual) step counts to estimated step counts from the proprietary AG Default algorithm and low frequency extension filter, as well as from 8 novel algorithms based on continuous wavelet transforms, fast Fourier transforms (FFTs), and peak detection. RESULTS: All algorithms had excellent agreement with manual step counts (ICC>0.9). The AG Default and FFT algorithms had the highest overall error (RMSE=17.81 and 19.91 steps, respectively), widest limits of agreement, and highest error during outdoor and ramp ambulation. The AG Default algorithm also had among the highest error during indoor ambulation and stairs, while a FFT algorithm had the highest error during stationary tasks. Peak detection algorithms, especially those using pre-set parameters with a trial-specific component, had among the lowest error across all activities (RMSE=4.07-8.99 steps). CONCLUSIONS: Because of its simplicity and accuracy across activities and clinical characteristics, we recommend the peak detection algorithm with set parameters to count steps using a prosthetic-worn AG among individuals with lower limb loss for clinical and research applications.

The Temporal Relationship Between Moderate to Vigorous Physical Activity and Secondary Conditions During the First Year After Moderate to Severe Traumatic Brain Injury.

OBJECTIVE: To determine the cross-sectional and temporal relationships between minutes per week of moderate to vigorous physical activity (MVPA) as measured by a wrist-worn accelerometer and secondary conditions in the first year after moderate to severe traumatic brain injury (TBI). DESIGN: Prospective longitudinal cohort study. SETTING: Four inpatient rehabilitation centers. PARTICIPANTS: Individuals (N = 180) with moderate-severe TBI enrolled in the TBI Model Systems Study. INTERVENTIONS: Participants wore a wrist accelerometer for 7 days immediately post discharge, and for 7 consecutive days at 6- and 12-months post injury. MAIN OUTCOME MEASURES: Minutes per week of MVPA from daily averages based on wrist worn accelerometer. Secondary conditions included depression (Patient Health Questionnaire-9), fatigue (PROMIS Fatigue), Pain (Numeric Rating Scale), Sleep (Pittsburgh Sleep Quality Index), and cognition (Brief Test of Adult Cognition by Telephone). RESULTS: At baseline, 6 and 12 months, 61%, 70% and 79% of the sample achieved at least 150 minutes per week of MVPA. The correlations between minutes of MVPA between baseline, 6 and 12 months were significant (r = 0.53-0.73), as were secondary conditions over these time points. However, no significant correlations were observed between minutes of MVPA and any secondary outcomes cross-sectionally or longitudinally at any time point. CONCLUSIONS: Given the robust relationships physical activity has with outcomes in the general population, further research is needed to understand the effect of physical activity in individuals with moderate-severe TBI.