New Insights Into Accelerometer-Measured Habitual Physical Activity and Sedentary Time During Early Recovery in Pediatric Concussion.

PURPOSE: Concussion management is shifting away from a rest-is-best approach, as data now suggest that exercise-is-medicine for this mild brain injury. Despite this, we have limited data on habitual physical activity following concussion. Therefore, our objective was to quantify accelerometer-measured physical activity and sedentary time in children with concussion (within the first month of injury) and healthy controls. We hypothesized that children with concussion would be less active than their healthy peers. METHODS: We performed a secondary analysis of prospectively collected accelerometer data. Our sample included children with concussion (n = 60, 31 females) and historical controls (n = 60) matched for age, sex, and season of accelerometer wear. RESULTS: Children with concussion were significantly more sedentary than controls (mean difference [MD], 38.3 min/d, P = .006), and spent less time performing light physical activity (MD, -19.5 min/d, P = .008), moderate physical activity (MD, -9.8 min/d, P < .001), and vigorous physical activity (MD, -12.0 min/d, P < .001); these differences were observed from 8:00 AM to 9:00 PM. Sex-specific analyses identified that girls with concussion were less active and more sedentary than both boys with concussion (P = .010) and healthy girls (P < .010). CONCLUSION: There is an activity deficit observed within the first month of pediatric concussion. Physical activity guidelines should address this while considering sex effects.

Physical Activity in Pediatric Inflammatory Bowel Disease: A Scoping Review.

BACKGROUND: Inflammatory bowel disease (IBD) is a chronic, systemic condition affecting the gastrointestinal tract. IBD can be severe and are associated with impairment in growth, school absences, abdominal pain, and fatigue. Physical activity (PA) could have an anti-inflammatory effect in addition to other benefits. It is important to address the possible risks, physiological effects of PA, and potential barriers, and facilitators for PA participation in pediatric IBD. However, potential barriers and facilitators to PA have yet to be adequately described. METHODS: We conducted a scoping review to map and describe the current literature on PA in pediatric IBD populations between 1980 and April 2022 using Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines for Scoping reviews. RESULTS: Nineteen articles were identified including 10 descriptive, 6 interventional, and 3 physiological responses to PA studies. Patients and healthy controls demonstrated similar responses to exercise. Barriers to participation were low self-esteem, body image, and active IBD symptoms. Facilitators included personal interest, activity with friends, and support from family. CONCLUSION: This review highlighted that PA participation may reduce in children with IBD-related symptoms. Short- and medium-term impacts of PA on immune modulation require further study; it is possible that regular PA does not negatively affect biomarkers of disease activity.

Accelerometer-measured physical activity, sedentary behavior, and sleep in children with cerebral palsy and their adherence to the 24-hour activity guidelines.

AIM: To measure and describe the 24-hour activities (i.e. physical activity, sedentary behavior, and sleep) and to examine adherence to the 24-hour activity guidelines among children with cerebral palsy (CP) using actigraphy. METHOD: Children's 24-hour activities were recorded over 7 days using hip- and wrist-worn ActiGraph wGT3X-BT accelerometers. RESULTS: In total, 362 days and 340 nights from 54 children with CP (Gross Motor Function Classification System [GMFCS] levels I-III; 44% females; median age [range] 6 years 6 months [3-12 years]) were included. Mean (SD) daily wear time was 746.2 (48.9) minutes, of which children spent on average 33.8% in light physical activity (251.6 [58.7] minutes per day), 5.2% in moderate-to-vigorous physical activity (38.5 [20.1] minutes per day), and the remaining 61.1% being sedentary (456.1 [80.4] minutes per day). Physical activity decreased while sedentary behavior increased with increasing GMFCS level. In total, 13% of all children met the physical activity recommendations, and 35% met the age-appropriate sleep duration recommendation. The proportion of children meeting the combined 24-hour guidelines for physical activity and sleep was low (5.9%), especially in those classified in GMFCS level III (0%). INTERPRETATION: The observed low 24-hour guideline adherence rates emphasize the importance of considering the entire continuum of movement behaviors in the care of children with CP, in efforts to promote healthy lifestyle behaviors and prevent negative health outcomes.

Does Sleep Quality Influence Recovery Outcomes After Postconcussive Injury in Children and Adolescents?

OBJECTIVE: To determine whether objective parameters of sleep quality differ throughout recovery between children and adolescents who experienced an early return to school (RTS) and those who had a delayed RTS or did not return at all during the study period. SETTING: Sleep parameters reflective of sleep quality were evaluated in participants' natural sleeping habitat throughout 9 weeks postinjury. PARTICIPANTS: Ninety-four children and adolescents (aged 5-18 years) with diagnosed concussion. DESIGN: Prospective cohort. Participants followed RTS protocols. MAIN MEASURES: Actigraphy-derived estimates of total sleep time (TST), sleep efficiency (SE), wake after sleep onset (WASO), average arousal length (AAL), and number of arousals (NOAs) per hour were assessed. The length of time from injury until RTS was determined for each participant. Participants were categorized into an early RTS or delayed RTS group based on their time to RTS. RESULTS: Both TST and SE were significantly greater in the early RTS group. WASO duration, AAL, and NOAs were significantly greater in the delayed RTS group. Differences between RTS groups were most apparent during weeks 1 to 5 postinjury. CONCLUSIONS AND CLINICAL IMPLICATIONS: Participants who returned to school earlier had significantly better objective sleep quality than participants who experienced a delayed RTS. This study provides evidence in support of a relationship between sleep quality and time to RTS in children and adolescents with concussion. Considering early monitoring of sleep, education regarding sleep hygiene, and access to age-appropriate sleep interventions may be helpful in pediatric concussion recovery.

A Pilot Study of Exercise Training for Children and Adolescents With Inflammatory Bowel Disease: An Evaluation of Feasibility, Safety, Satisfaction, and Efficacy.

BACKGROUND: Children with inflammatory bowel disease (IBD) experience extraintestinal side effects including altered body composition, impaired muscle strength, and aerobic capacity. Exercise training may remedy these issues. PURPOSE: To assess the feasibility, safety, participant satisfaction, and efficacy of a training program for youth with IBD. METHODS: Children with IBD completed 16 weeks of training (2 supervised + 1 home sessions per week). Feasibility was assessed by tracking recruitment, adherence, and compliance rates. Safety was assessed by tracking symptoms and adverse events. Posttraining interviews gauged satisfaction. Circulating inflammatory markers, body composition, muscle strength, aerobic fitness, and habitual physical activity were measured at baseline, midtraining (8 wk), and posttraining. RESULTS: Eleven youth were recruited and 10 completed the study. Participants adhered to 28 (1) of 32 prescribed supervised sessions and 8 (4) of 16 prescribed home sessions. There were no adverse events, and overall feedback on training was positive. Posttraining, we observed an increase in lean mass (+2.4 [1.1] kg), bone density (+0.0124 [0.015] g·cm-2), aerobic fitness (+2.8 [5.7] mL·kg LM-1· min-1), and vigorous physical activity levels (+13.09 [8.95] min·h-1) but no change in inflammation or muscle strength. CONCLUSION: Supervised exercise training is feasible, safe, and effective for youth with IBD and should be encouraged.

Grip strength is lower in adults born with extremely low birth weight compared to term-born controls.

BACKGROUND: Grip strength predicts long-term morbidity and mortality in adults. We compared grip strength in adults born with extremely low birth weight (ELBW; under 1 kg) and a normal birth weight control group (NBW) and describe change in grip strength over a 10-year period in a longitudinal cohort study of preterm birth. METHODS: Grip strength, body composition, and device-measured physical activity were assessed in 95 mature adults (MA) born ELBW (age 31.6 (1.6) mean (SD) years, 59 females) and 88 born NBW (age 31.9 (1.4) years, 52 females). Regression models were used to examine the effect of perinatal factors, body composition, physical activity, and physical self-efficacy on grip strength. RESULTS: Grip strength was lower in MA born ELBW compared to NBW (31.8 (10.0) vs. 39.8 (11.2) kg; p < 0.001). Birth weight group was associated with grip strength independent of sex, height, and lean mass index, but device-measured physical activity was not. The change in grip strength from mid-20s to MA was similar in ELBW and NBW participants. DISCUSSION: Grip strength in MA born ELBW is low and is similar to a reference group 25-30 years older, suggesting higher risk for cardiovascular and all-cause mortality. IMPACT: Adults born extremely preterm have reduced grip strength compared to control participants born at full term. Reduced grip strength is a predictor of frailty and increased cardiovascular disease risk. Change in grip strength from age in mid-20s to mid-30s is similar in those born preterm and full-term-born controls. Grip strength is related to lean mass and not to device-measured physical activity-and correlates of grip strength are similar in those born preterm and term-born controls. Grip strength is a simple measure that may provide information about the health of adults born preterm.

The Effects of Exercise Serum From Prepubertal Girls and Women on In Vitro Myoblast and Osteoblast Proliferation and Differentiation.

PURPOSE: In girls and women, the authors studied the effects of an acute bout of low-impact, moderate-intensity exercise serum on myoblast and osteoblast proliferation in vitro. METHODS: A total of 12 pre/early pubertal girls (8-10 y old) and 12 women (20-30 y old) cycled at 60% VO2max for 1 hour followed by 1-hour recovery. Blood samples were collected at rest, mid-exercise, end of exercise, mid-recovery, and end of recovery. C2C12 myoblasts and MC3T3E1 osteoblasts were incubated with serum from each time point for 1 hour, then monitored for 24 hours (myoblasts) or 36 hours (osteoblasts) to examine proliferation. Cells were also monitored for 6 days (myoblasts) to examine myotube formation and 21 days (osteoblasts) to examine mineralization. RESULTS: Exercise did not affect myoblast or osteoblast proliferation. Girls exhibited lower cell proliferation relative to women at end of exercise (osteoblasts, P = .041; myoblasts, P = .029) and mid-recovery (osteoblasts, P = .010). Mineralization was lower at end of recovery relative to rest (P = .014) in both girls and women. Myotube formation was not affected by exercise or group. CONCLUSION: The systemic environment following one acute bout of low-impact moderate-intensity exercise in girls and women does not elicit osteoblast or myoblast activity in vitro. Differences in myoblast and osteoblast proliferation between girls and women may be influenced by maturation.

Physical activity and sedentary behaviour in children with spina bifida.

AIM: To describe active and sedentary time in children with spina bifida and to compare their physical activity on weekdays versus weekends. METHOD: In this exploratory cross-sectional study, data from 13 Canadian and 22 Dutch children with spina bifida (14 females, 21 males; mean age 10y 11mo, standard deviation [SD] 3y 6mo, range 5y 6mo-18y; Hoffer classification distribution: community [n=28], household [n=3], non-functional [n=3], and non-ambulator [n=1]) were analysed. Objective measures of physical activity and sedentary behaviour were obtained by using ActiGraph or Actiheart activity monitors. Data for the participants wearing the ActiGraph were compared with age- and sex-matched controls that were developing typically using independent-samples t-tests. Activity data collected on weekdays was compared to those on weekends. RESULTS: ActiGraph data demonstrated children with spina bifida spent more time sedentary (mean [SD] 49.5min/h [5.78]) and less time in moderate to vigorous physical activity (mean [SD] 2.33min/h [1.61]) compared with the typically developing group (mean [SD] 41.0min/h [5.76] and 5.46min/h [2.13], p=0.001 and p<0.001 respectively). For both ActiGraph- and Actiheart-derived data, physical activity and sedentary time were not significantly different between weekdays and weekends. INTERPRETATION: Children with spina bifida have reduced levels of physical activity and increased sedentary behaviour, with no statistical differences seen between weekdays and weekends. Several methodological issues related to activity monitoring warrant consideration when choosing the appropriate method to quantify physical activity and sedentary behaviour. WHAT THIS PAPER ADDS: Reduced levels of physical activity and sedentary time were quantified in children with spina bifida. Objective quantification of physical behaviour in ambulatory and non-ambulatory school-aged children with spina bifida is possible.

ACTIVIDAD FÍSICA Y COMPORTAMIENTO SEDENTARIO EN NIÑOS CON ESPINA BÍFIDA: OBJETIVO: Describir el tiempo activo y sedentario en niños con espina bífida y comparar su actividad física entre semana y fines de semana. MÉTODO: En este estudio exploratorio de corte transversal, datos de 13 niños canadienses y 22 holandeses con espina bífida (14 mujeres, 21 varones; edad media 10 años 11 meses, desviación estándar [DE] 3 años 6 meses, rango 5 años 6 meses - 18 años; se analizaron en base a la distribución basada en la clasificación de Hoffer: comunidad [n = 28], hogar [n = 3], no funcional [n = 3] y no ambulatorios [n = 1]). Se obtuvieron medidas objetivas de actividad física y comportamiento sedentario mediante el uso de monitores de actividad ActiGraph o Actiheart. Los datos de los participantes que usaban el ActiGraph se compararon con los niños con desarrollo típicos como controles, apareados por edad y sexo usando pruebas t de muestras independientes. Los datos de actividad recopilados durante la semana se compararon con los de los fines de semana. RESULTADOS: Los datos de ActiGraph demostraron que los niños con espina bífida pasaron más tiempo sedentarios (media [DE] 49,5min / h [5,78]) y menos tiempo en actividades físicas moderadas a intensas (media [DE] 2,33min / h [1,61]) en comparación con el grupo control (media [DE] 41,0min / h [5,76] y 5,46min / h [2,13], p = 0,001 y p <0,001 respectivamente). Tanto para los datos derivados de ActiGraph como de Actiheart, la actividad física y el tiempo sedentario no fueron significativamente diferentes entre semana y fines de semana. INTERPRETACIÓN: Los niños con espina bífida tienen niveles reducidos de actividad física y un mayor comportamiento sedentario, sin diferencias estadísticas observadas entre semana y fines de semana. Al elegir un método apropiado para cuantificar la actividad física y el comportamiento sedentario se deben considerar varios problemas metodológicos relacionados con el monitoreo de la actividad en esta población.

ATIVIDADE FÍSICA E COMPORTAMENTO SEDENTÁRIO EM CRIANÇAS COM ESPINHA BÍFIDA: OBJETIVO: Descrever o tempo ativo e sedentário de crianças com espinha bífida e comparar sua atividade física durante a semana versus fins de semana. MÉTODO: Neste estudo exploratório transversal, dados de 13 crianças canadenses e 22 crianças holandesas com espinha bífida (14 do sexo feminino, 21 do sexo masculino; médida de idade 10a 11m, desvio padrão [DP] 3a 6m, variação 5a 6m-18a; Distribuição da classificação de Hoffer: comunidade [n=28], domiciliar [n=3], não funcional [n=3], e não ambulatório [n=1]) foram analisados. Medidas objetivas de atividade física e comportamento sedentário foram obtidas por meio de monitores de atividade ActiGraph ou Actiheart. Dados para os participantes que usaram ActiGraph foram comparados com controles pareados por idade e sexo que tinha desenvolvimento típico usando testes t para amostras independentes. Dados de atividade coletados durante a semana foram comparados com os dados de finais de semana. RESULTADOS: Os dados do ActiGraph demonstraram que crianças com espinha bífida passaram mais tempo sedentário (média [DP] 49,5min/h [5,78]) e menos tempo em atividade física vigorosa (média [DP] 2,33min/h [1,61]) comparados com o grupo com desenvolvimento típico (média [DP] 41,0min/h [5,76] e 5,46min/h [2,13], p=0,001 and p<0,001 respectivamente). Para os dados derivados do ActiGraph- e Actiheart, a atividade física e o tempo sedentário não foram significativamente diferentes comparando os dias da semana com os fins de semana. INTERPRETAÇÃO: Crianças com espinha bífida têm níveis reduzidos de atividade física e comportamento sedentário aumentado, sem diferenças estatísticas quando comparados os dias da semana. Várias questões metodológicas relacionadas ao monitoramento de atividades indicam necessidade de refletir quanto à escolha do método apropriado para quantificar a ativiade física e comportamento sedentário.

Focus on Risk Factors for Cardiometabolic Disease in Cerebral Palsy: Toward a Core Set of Outcome Measurement Instruments.

OBJECTIVE: To identify existing outcome measurement instruments (OMIs) assessing risk factors for cardiometabolic disease in adolescents and adults with cerebral palsy (CP) reported on in the literature or used in the field. DATA SOURCES: The COnsensus-based Standards for the selection of health Measurement Instruments database of systematic reviews and 4 electronic databases (Embase, MEDLINE/Ovid, MEDLINE/Pubmed, PsychINFO) were searched up to June 19, 2017, that yielded 2594 articles. Experts in the field were consulted to identify any additional OMIs. STUDY SELECTION: Two reviewers independently applied inclusion criteria to select eligible studies using or evaluating measurement properties of OMIs assessing 1 of 8 outcomes: cardiorespiratory endurance, body size, body composition, physical behavior, sleep, nutrition, blood pressure, and blood lipids and glucose. Studies with an experimental or observational design including ≥10 adolescents or adults with CP were included. DATA EXTRACTION: One reviewer extracted data that were summarized for study and sample characteristics, outcomes, OMIs used, and if applicable data on measurement properties. Two reviewers rated the methodological quality and the quality of the OMIs. Feasibility for clinical practice and research was rated by experts in the field. DATA SYNTHESIS: Ninety OMIs were identified from 56 included articles and by the experts. Seventy OMIs pertained to cardiorespiratory endurance, body size, body composition, and physical behavior, whereas only 5 were identified for sleep and nutrition. Overall synthesis revealed that there is moderate to poor evidence for good quality of OMIs in this population. Based on feasibility for clinical practice, experts agreed on a single OMI per outcome (and 2 for cardiorespiratory endurance) to be included in a core set. CONCLUSION: Despite the range of available OMIs to assess risk factors for cardiometabolic disease in adolescents and adults with CP, evidence of good quality is often lacking. Nonetheless, a preliminary core set of 9 OMIs was systematically developed.

Thermoregulation in boys and men exercising at the same heat production per unit body mass.

PURPOSE: Child-adult thermoregulatory comparisons may be biased by differences in metabolic heat production ([Formula: see text]). We compared thermoregulatory responses of boys and men exercising at two intensities prescribed to elicit either a fixed [Formula: see text] per unit body mass (BM) or a fixed absolute [Formula: see text]. METHODS: Ten boys (10-12 years) and 10 men (19-25 years) performed 4 × 20-min cycling at a fixed [Formula: see text] per BM (W kg(-1)) at 35 °C and 35 % relative humidity (MENREL). Men also cycled (MENABS) at the same absolute [Formula: see text] (in W) as the boys. RESULTS: [Formula: see text] was lower in boys compared with MENREL, but similar to MENABS (mean ± SD, 233.6 ± 38.4, 396.5 ± 72.3, 233.6 ± 34.1 W, respectively, P < 0.001). Conversely, [Formula: see text] per unit BM was similar between boys and MENREL, and lower in MENABS (5.7 ± 1.0, 5.6 ± 0.8 and 3.3 ± 0.3 W kg(-1), respectively; P < 0.001). The change in rectal temperature was similar between boys and MENREL (0.6 ± 0.2 vs. 0.7 ± 0.2 °C, P = 0.92) but was lower in MENABS (0.3 ± 0.2 °C, P = 0.004). Sweat volume was lower in boys compared to MENABS (500 ± 173 vs. 710 ± 150 mL; P = 0.041), despite the same evaporative heat balance requirement (E req) (199.1 ± 34.2 vs. 201.0 ± 32.7 W, P = 0.87). CONCLUSION: Boys and men demonstrated similar thermoregulatory responses to 80 min of exercise in the heat performed at a fixed [Formula: see text] per unit BM. Sweat volume was lower in boys compared to men, despite similarities in absolute [Formula: see text] and E req.

The Effect of Postexercise Milk Protein Intake on Rehydration of Children.

PURPOSE: In adults, rehydration after exercise in the heat can be enhanced with a protein-containing beverage; however, whether this applies to children remains unknown. This study examined the effect of milk protein intake on postexercise rehydration in children. METHOD: Fifteen children (10-12 years) performed three exercise trials in the heat (34.4 ± 0.2 °C, 47.9 ± 1.1% relative humidity). In a randomized, counterbalanced crossover design, participants consumed iso-caloric and electrolyte-matched beverages containing 0 g (CONT), 0.76 g (Lo-PRO) or 1.5 g (Hi-PRO) of milk protein/100 mL in a volume equal to 150% of their body mass (BM) loss during exercise. BM was then assessed over 4 h of recovery. RESULTS: Fluid balance demonstrated a significant condition × time interaction (p = .012) throughout recovery; Hi-PRO was less negative than CONT at 2 hr (p = .01) and tended to be less negative at 3 h (p = .07). Compared with CONT, beverage retention was enhanced by Hi-PRO at 2 h (p < .05). CONCLUSION: A postexercise beverage containing milk protein can favorably affect fluid retention in children. Further research is needed to determine the optimal volume and composition of a rehydration beverage for complete restoration of fluid balance.

Fitness and physical activity in youth with type 1 diabetes mellitus in good or poor glycemic control.

BACKGROUND: Patients with type 1 diabetes mellitus (T1DM) may experience poor muscle health as a result of chronic hyperglycemia. Despite this, muscle function in children with T1DM with good or poor glycemic control has yet to be examined in detail. OBJECTIVE: To assess differences in muscle-related fitness variables in children with T1DM with good glycemic control (T1DM-G), as well as those with poor glycemic control (T1DM-P), and non-diabetic, healthy controls. SUBJECTS: Eight children with T1DM-G [glycosylated hemoglobin (HbA1c) ≤ 7.5% for 9 months], eight children with T1DM-P (HbA1c ≥ 9.0% for 9 months), and eight healthy controls completed one exercise session. METHODS: Anaerobic and aerobic muscle functions were assessed with a maximal isometric grip strength test, a Wingate test, and an incremental continuous cycling test until exhaustion. Blood samples were collected at rest to determine HbA1c at the time of testing. Physical activity was monitored over 7 d using accelerometry. RESULTS: Children with T1DM-P displayed lower peak oxygen consumption (VO2peak ) values (mL/kg/min) compared to healthy controls (T1DM-P: 33.2 ± 5.6, controls: 43.5 ± 6.3, p < 0.01), while T1DM-G (43.5 ± 6.3) had values similar to controls and T1DM-P. There was a negative relationship between VO2peak and HbA1c% (r = -0.54, p < 0.01). All groups were similar in all other fitness variables. There were no group differences in physical activity variables. CONCLUSION: Children with T1DM-G did not display signs of impaired muscle function, while children with T1DM-P have signs of altered aerobic muscle capacity.

Effects of acute exercise on markers of inflammation in pediatric chronic kidney disease: a pilot study.

BACKGROUND: Children and adolescents with chronic kidney disease (CKD) are chronically exposed to high levels of inflammation, placing them at an increased risk of secondary health complications. Regular exercise may represent an effective therapy to reduce inflammation. The aims of this pilot study were to determine the effects of acute exercise on inflammation and immune cell counts in CKD. METHODS: Nine children and adolescents (4 males) with CKD stages III-V performed a graded exercise test to determine peak oxygen uptake (VO2peak). Following a 10-min break, participants cycled for 20 min at 50 % of VO2peak. Blood samples were collected before and after the exercise period for the determination of complete blood counts, natural killer cells (NK(bright), NK(dim)) and circulating progenitor cell (CPC) counts, as well as interleukin-6 (IL-6), and tumor necrosis factor-α (TNF-α) concentrations. RESULTS: Complete blood counts and NK(dim) cell and CPC counts were unchanged with exercise. Following exercise, NK(bright) cell counts increased (7.4 ± 4.3 vs. 12.2 ± 8.3 × 10(6) cells/L; p = 0.02), while trends were observed for an increase in IL-6 (2.1 ± 2.2 vs. 2.7 ± 2.6 pg/mL; p = 0.08), decrease in TNF-α (4.5 ± 1.2 vs. 4.2 ± 1.0 pg/mL; p = 0.08) and an increase in the IL-6:TNF-α ratio (0.6 ± 0.7 vs. 0.8 ± 0.8; p = 0.07). CONCLUSIONS: Our findings suggest that acute exercise may create an anti-inflammatory environment in children and adolescents with CKD stages III-V.

Sedentary Time and Screen-Based Sedentary Behaviors of Children With a Chronic Disease.

The objectives of this study were to (i) assess sedentary time and prevalence of screen-based sedentary behaviors of children with a chronic disease and (ii) compare sedentary time and prevalence of screen-based sedentary behaviors to age- and sex-matched healthy controls. Sixty-five children (aged 6-18 years) with a chronic disease participated: survivors of a brain tumor, hemophilia, type 1 diabetes mellitus, juvenile idiopathic arthritis, cystic fibrosis, and Crohn's disease. Twenty-nine of these participants were compared with age- and sex-matched healthy controls. Sedentary time was measured objectively by an ActiGraph GT1M or GT3× accelerometer worn for 7 consecutive days and defined as less than 100 counts per min. A questionnaire was used to assess screen-based sedentary behaviors. Children with a chronic disease engaged in an average of 10.2 ± 1.4 hr of sedentary time per day, which comprised 76.5 ± 7.1% of average daily monitoring time. There were no differences between children with a chronic disease and controls in sedentary time (adjusted for wear time, p = .06) or in the prevalence of TV watching, and computer or video game usage for varying durations (p = .78, p = .39 and, p = .32 respectively). Children with a chronic disease, though relatively healthy, accumulate high levels of sedentary time, similar to those of their healthy peers.

Objectively measured physical activity levels of young children with congenital heart disease.

UNLABELLED: Physical activity tends to be lower in school-age children with congenital heart disease than in healthy controls. To the best of our knowledge, objectively measured physical activity levels of preschool-age children with congenital heart disease have not been studied. METHODS: A total of 10 children with either coarctation of the aorta (n=6; age 3.8±0.9) or tetralogy of Fallot (n=4, age 4.3±0.9) were recruited from the cardiology unit of McMaster Children's Hospital. Height (103.7±8.2 cm) and weight (17.3±2.7 kg) measurements were recorded, and physical activity was determined using accelerometry over 7 consecutive days. Patients were compared with age-, sex-, and season of data acquisition-matched controls. Parents completed a questionnaire regarding the child's physical activity and sedentary behaviours. RESULTS: Patients spent on average 219.4±39.9 minutes engaged in total physical activity per day at the following intensities: light, 147.5±22.3; moderate, 44.0±11.8; moderate-to-vigorous, 71.9±22.6; and vigorous, 27.9±11.7. No significant differences were observed between patients and controls for total physical activity (p=0.80) or any of the intensities (p=0.71, 0.46, 0.43, and 0.45, respectively). Only 40% of patients and controls met the new Canadian Physical Activity Guidelines for the Early Years of at least 180 minutes of physical activity at any intensity every day. Of the patients' parents, 90% believed that their child was as active, if not more active, than his/her siblings, and 80% of parents reported their child spending 1-3 hours in screen time activities daily. CONCLUSION: Children aged 3-5 years old with congenital heart disease have comparable physical activity levels to age-, sex-, and season-matched controls, and many do not meet Canadian Physical Activity Guidelines.

Accelerometer techniques for capturing human movement validated against direct observation: a scoping review.

INTRODUCTION: Accelerometers are devices commonly used to measure human physical activity and sedentary time. Accelerometer capabilities and analytical techniques have evolved rapidly, making it difficult for researchers to keep track of advances and best practices for data processing and analysis. OBJECTIVE: The objective of this scoping review is to determine the existing methods for analyzing accelerometer data for capturing human movement which have been validated against the criterion measure of direct observation. METHODS: This scoping review searched 14 academic and 5 grey databases. Two independent raters screened by title and abstract, then full text. Data were extracted using Microsoft Excel and checked by an independent reviewer. RESULTS: The search yielded 1039 papers and the final analysis included 115 papers. 71 unique accelerometer models were used across a total of 4217 participants. While all studies underwent validation from direct observation, most direct observation occurred live (55%) or using recordings (42%). Analysis techniques included machine learning approaches (22%), the use of existing cut-points (18%), ROC curves to determine cut-points (14%), and other strategies including regressions and non-machine learning algorithms (8%). DISCUSSION: Machine learning techniques are becoming more prevalent and are often used for activity identification. Cut-point methods are still frequently used. Activity intensity is the most assessed activity outcome; however, both the analyses and outcomes assessed vary by wear location. CONCLUSIONS: This scoping review provides a comprehensive overview of accelerometer analysis and validation techniques using direct observation and is a useful tool for researchers using accelerometers.

Reliability and validity of short-term performance tests for wheelchair-using children and adolescents with cerebral palsy.

AIM: To investigate the test-retest reproducibility of the Muscle Power Sprint Test (MPST), the 10 × 5-m sprint test, and the arm-cranking Wingate Anaerobic Test (WAnT) in children and adolescents with cerebral palsy (CP). A secondary objective was to assess the construct validity of the MPST. METHOD: Twenty-three participants with spastic CP (mean age 13 y 3 mo, range 7-18 y, SD 3.6 y; 18 males, five females, two classified as having spastic unilateral CP, 21 as having spastic bilateral CP) using a manual wheelchair for at least part of the day were recruited and tested in different rehabilitation settings in the Netherlands. Participants were classified as in Gross Motor Function Classification System Expanded and Revised (GMFCS-E&R) levels III and IV. RESULTS: Intraclass correlation coefficients (range 0.93-0.99; 95% confidence interval 0.82-1.0) for all variables indicated highly acceptable reproducibility. Limits of agreement analysis revealed satisfactory levels of agreement. The MPST variables demonstrated very strong significant positive correlations for peak power and mean power from both tests (peak power: r=0.91, p<0.001; mean power: r=0.88, p<0.001). INTERPRETATION: The MPST, the 10 × 5-m sprint test, and the arm-cranking WAnT are reproducible tests for measuring anaerobic performance and agility in adolescents with spastic CP who self-propel a manual wheelchair. The MPST has been shown to be a valid test to measure anaerobic performance in this population.

Chemokine (C-C motif) Ligand 2 is a potential biomarker of inflammation & physical fitness in obese children: a cross-sectional study.

BACKGROUND: Obesity is a global epidemic that is impacting children around the world. Obesity is a chronic inflammatory state with enhanced production of multiple cytokines and chemokines. Chemokine (C-C motif) Ligand 2 (CCL2) is produced by immune and metabolic cells and attracts immune cells into liver, muscle and adipose tissue, resulting in initiation and propagation of the inflammatory response in obesity. How obesity and fitness affect the production of this chemokine in children is unknown.This study tested the hypotheses that CCL2 levels are higher in obese children when compared to lean controls, and that fitness modulates CCL2 levels allowing its use as a biomarker of fitness. METHODS: This was a cross sectional case-control study conducted in a Pediatric Tertiary care center in Hamilton, Ontario, Canada. Controls were recruited from the community. This study recruited overweight/obese children (BMI ≥ 85th percentile, n = 18, 9 female, mean age 14.0 ± 2.6 years) and lean controls (BMI < 85th percentile, n = 18, 8 female, mean age 14.0 ± 2.6 years) matched for age, sex and biological maturation.Aerobic fitness test was done using a cycle ergometer performing the McMaster All-Out Progressive Continuous Cycling test to exhaustion to determine peak oxygen uptake. Fasting CCL2 samples were taken prior to test. Categorical variables including subject categorization into different aerobic fitness levels in overweight/obese and lean children was reported based on the median split in each group. RESULTS: Obese participants had significantly higher CCL2 levels when compared to lean group (150.4 ± 61.85 pg/ml versus 112.7 ± 38 pg/ml, p-value 0.034).To establish if CCL2 is a biomarker of fitness, we divided the groups based on their fitness levels. There was a main effect for group (F (3,32) = 3.2, p = 0.036). Obese high fitness group were similar to lean unfit and fit participants. Post-hoc analysis revealed that the overweight/obese low fitness group had significantly higher level of CCL2 compared to the lean low fitness group when adjusted to age, sex and maturity offset (F (3,29) = 3.1, p = 0.04). CONCLUSIONS: CCL2 serves a dual role as a potential biomarker of inflammation and fitness in obese children.

Validity of the muscle power sprint test in ambulatory youth with cerebral palsy.

PURPOSE: To validate the Muscle Power Sprint Test (MPST) against the Wingate Anaerobic cycling Test (WAnT) in a group of youth with cerebral palsy (CP). METHODS: Twenty children and adolescents (11 boys and 9 girls; mean age = 14.8 years) with spastic CP, and classified as either level I or II of the Gross Motor Function Classification System, completed the study. RESULTS: Very strong significant correlations were seen for peak power (PP) and mean power (MP) from the MPST and WAnT PP and MP values (PP: r = 0.731, P < .001; MP: r = 0.903, P < .001). CONCLUSIONS: The results of this study show that the MPST is a valid test for measuring anaerobic capacity in children with CP, and that this test can be used as an evaluation tool for anaerobic performance in exercise interventions focusing on children and adolescents with CP who are able to walk or run independently.

The temporal and bi-directional relationship between physical activity and sleep in ambulatory children with cerebral palsy.

PURPOSE: Exploring the temporal and bi-directional relationship between device-based measures of physical activity and sleep in ambulatory children with cerebral palsy (CP). MATERIALS AND METHODS: 24-hour activity data were collected from children with CP (n = 51, 43% girls, mean age (range); 6.8 (3-12) years; Gross Motor Function Classification System levels I to III). Nocturnal sleep parameters and daily physical activity were measured for seven consecutive days and nights using ActiGraph GT3X accelerometers. Linear mixed models were constructed to explore the relationships between sleep and activity. RESULTS: Light and moderate-to-vigorous activity were negatively associated with sleep efficiency (SE) (resp. p = 0.04, p = 0.010) and total sleep time (TST) (resp. p = 0.007, p = 0.016) the following night. Sedentary time was positively associated with SE and TST the following night (resp. p = 0.014, p = 0.004). SE and TST were positively associated with sedentary time (resp. p = 0.011, p = 0.001) and negatively with moderate-to-vigorous physical activity (resp. p < 0.001, p = 0.002) the following day. Total bedtime and TST were negatively associated with light physical activity (resp. p = 0.046, p = 0.004) the following day. CONCLUSIONS: The findings from this study suggest that ambulatory children with CP may not sleep better after physical activity, and vice versa, indicating that the relationship is complex and needs further investigation.

The use of device-based accelerometry is a feasible method to measure 24-hour activity patterns with sleep and physical activity in ambulatory children with cerebral palsy.The relationships between sleep and physical activity in children with cerebral palsy are not as expected based on patterns shown in peers with typical development.Interventions for sleep in children with cerebral palsy require a holistic approach, focusing on daily physical activity patterns and relevant child- and contextual factors.