Evening types have social jet lag and metabolic alterations in school-age children.

Chronotype has been mostly assessed with subjective scales. Objective assessment has been undertaken with actigraphy, although problems may occur in classifying chronotype. The aims of the study were to assess chronotype in school-age children using a novel integrative measurement (TAP) derived from non-invasive assessments of wrist temperature (T) physical activity (A) and body position (P) and to explore associations between chronotype, sleep disturbances, and metabolic components. Four-hundred-thirty-two children of 8-12 years were recruited from a Mediterranean area of Spain. Measurements were: (a) Chronotype objectively (7-day-rhythms of TAP) and subjectively measured (Munich-chronotype-self-reported questionnaire); (b) sleep rhythms and light exposition; (c) 7-day-diaries of food intake; (d) anthropometry and metabolic parameters; (e) academic scores. TAP acrophase was able to assess eveningness. As compared to more morning-types, more evening-types displayed lower amplitude in temperature rhythms, increased physical activity in the evening, delayed sleep and midpoint of intake and had more frequent social jet lag (P < 0.05). More evening-types had higher light intensity at 2 h before sleep and lower melatonin values (01:00 h). Eveningness associated with higher BMI and metabolic risk (higher values of insulin, glucose, triglycerides and cholesterol). Evening-types presented better grades in art. In conclusion, more evening-types, as objectively assessed, presented sleep alterations, social jet lag, obesity and higher metabolic risk.

Circadian health differs between boys and girls as assessed by non-invasive tools in school-aged children.

BACKGROUND & AIMS: Assessment of circadian health is confined to adults. However, understanding circadian status of school-aged children is necessary due to its health implications. The aim was to develop 1) a protocol to assess circadian function in school-aged children by combining the best non-invasive tools previously validated in adults; 2) a score to capture circadian function in children including food timing. This protocol will allow to explore gender differences and to compare the circadian function of school-aged children with adults from the same Mediterranean area. METHODS: Healthy children (8-12 y) from 3 schools in a Mediterranean area of Spain were recruited (n = 248; 125 males and 123 females). Several non-invasive tools were used: a) 7-day-diaries of food timing and food intake, physical-activity and sleep, b) Munich-chronotype-self-reported-questionnaire; c) cortisol and melatonin saliva determinations; d) 7-day-rhythms of wrist temperature (T), activity (A), position (P) and the integrative variable TAP e) 7-day-light exposure. RESULTS: We have constructed the first school-aged children population for the assessment of circadian function (ONTIME-Jr) and a new circadian score has been developed. Among circadian-related measures, TAP was the most suitable and reliable to determine circadian system characteristics. Circadian function was better in girls than in boys [circadian score (AU) Mean ± SD (girls, 1216 ± 153 vs. 1159 ± 173 boys, P = 0.012)], and also in school-aged children than in adults from the same Mediterranean area (Circadian-Function-Index: children 0.47 ± 0.06 vs. adults 0.45 ± 0.06 P = 0.001). CONCLUSIONS: A new protocol, including TAP and food timing, demonstrated to be reliable in assessing circadian function in children. These non-invasive techniques provide the wherewithal for paediatricians to assess circadian function in clinical practice. TRIAL REGISTRATION: Chronobiology and childhood obesity (ONTIME-Jr: Obesity, Nutrigenetics, Timing and Mediterranean, Junior). ClinicalTrials.gov ID: NCT02895282, October 2014.

Physical Fitness Reference Standards in French Youth: The BOUGE Program.

The aim of this study was to establish sex- and age-specific physical fitness percentiles in French youth. A sample of 11,186 children and adolescents (5,546 boys and 5,640 girls), aged between 10 and 15 years, was assessed in the French national BOUGE study. Participants were tested for their cardiorespiratory fitness, muscular endurance, speed, flexibility, and agility using the following tests: 20-m shuttle run tests, curl-ups test, 50-m sprint test, back-saver sit and reach test, and 10 × 5-m shuttle run test. Percentile values were estimated for French youth as a function of age stratified by sex using the generalized additive model for location, scale, and shape (GAMLSS). In general, physical fitness was better in boys than in girls, except for the back-saver sit and reach test, in which girls performed better. Except for the back-saver sit and reach test and 10 × 5-m shuttle run test, physical fitness performance was significantly associated with age. Sex- and age-specific normative values for physical fitness tests in French youth expressed as percentiles from the fifth to the 95th are provided. Reference values provide normative data for French youth. The data are useful in identifying special needs for appropriate intervention programs.

Physical activity using wrist-worn accelerometers: comparison of dominant and non-dominant wrist.

The purpose of this study was to determine whether there is a difference in physical activity assessment between a wrist-worn accelerometer at the dominant or non-dominant arm. The secondary purpose was to assess the concurrent validity of measures of physical activity from the wrist-worn accelerometer and the waist-worn accelerometer. Forty adults wore three accelerometers simultaneously, one on the waist and one each on the non-dominant wrist and dominant wrist, respectively, for 24 consecutive hours of free-living conditions. Data were uploaded from the monitor to a computer following a 1-day test period. There were no significant differences in physical activity when comparing the dominant versus the non-dominant wrist, regardless of axis (P>0·05). Mean daily accelerometer output data from both wrists were strongly correlated with average counts per minute from the ActiGraph worn around the waist (r = 0·88, P<0·001). Findings suggest that the choice to wear the accelerometer on the non-dominant or dominant wrist has no impact on results. Data from this study contribute to the knowledge of how to best assess physical activity habits.

Prevalence of overweight, obesity, underweight and normal weight in French youth from 2009 to 2013.

OBJECTIVE: To determine the prevalence of underweight, overweight and obesity in French youth from 2009 to 2013 and to determine if there are differences in weight categories according to socio-economic status. DESIGN: Cross-sectional study performed in different regions of France. Physical measures included weight, height and BMI. Underweight, overweight and obesity were defined according to age- and sex-specific BMI cut-off points from the International Obesity Task Force. SETTING: France. SUBJECTS: Children and adolescents (n 9670; 4836 boys, 4834 girls) from the French national BOUGE Program between 2009 and 2013. RESULTS: The prevalence of obesity was higher in boys than girls (P0·05) and remained unchanged in boys (7·1-7·3 %) between 2009 and 2013. Overweight and obesity were higher in low socio-economic families (P<0·0001). CONCLUSIONS: Findings suggest that the prevalence of overweight was stable although high in French children and adolescents, while the prevalence of obesity increased significantly. Changes in underweight, although not significant, were high in girls and merit further attention. Improving public health interventions, especially in high-risk low socio-economic populations, may help to modify the behaviour that contributes to underweight, overweight and obesity in young boys and girls.

Physical fitness levels of adolescents in the Ile de France region: comparisons with European standards and relevance for future cardiovascular risk.

The aim was to assess physical fitness in French schoolchildren in the region of Ile de France and to compare the results with European countries. The relationship between physical fitness and future health profile was of particular interest. Participants were 1851 French youth in the Ile de France region. Cardiorespiratory fitness, muscular endurance, speed, flexibility and speed agility were tested. Independent t-tests were used to compare differences between different variables. Spearman's rho correlation coefficients assessed the relationship between body mass index, socio-economic status and physical fitness. Boys were physically fitter than girls with the most significant difference being in agility. Subjects of normal weight have significantly better results than overweight or obese adolescents (+10·9% to 56·1%) (P<0·05). Subjects with high socio-economic status had better physical fitness than those with low socio-economic status (+0·5% to 9·4%) (P<0·05). Results also showed that the percentage of adolescents at increased future cardiovascular risk was 15·3% and 10·2% for boys and girls, respectively. Physical fitness in French schoolchildren living in the region of Ile de France is relatively low and unfavourable, especially in girls, when compared with existing European test results. In contrast, the adolescent boys are generally fitter and also above the average of the European data. Introducing a health promotion curriculum in the schools of Ile de France is suggested to improve health and physical fitness.

Reliability of health-related physical fitness tests in adolescents: the MOVE Program.

The aim was to examine the reliability of health-related physical fitness tests that were used in a French health promotion program 'Move…A priority for your health'. Participants were 174 French youth (88 children and 86 adolescents) aged 8·2-16·2 years. Aerobic fitness, muscular strength, speed and flexibility were tested using 20-m shuttle run test, ½ mile run test, basketball throw, standing long jump, shoulder stretch and 20/30/50-m sprint tests. Reliability was calculated for the basketball throw, standing long jump, shoulder stretch and sprint tests. The tests were performed two times, 1 week apart on the same day of the week. Reliability was examined with intraclass correlation coefficients (ICCs) and Bland-Altman analysis. With the exception of the ½ mile run test, which resulted in moderate agreement (0·66), all tests had high reliability. ICCs were 0·97, 0·93, 0·91 and 0·93 for the sprint test, basketball throw, shoulder stretch and the standing long jump, respectively. The differences obtained between the first and the second trial were non-significant. Results from this study indicate that the BOUGE health-related physical fitness battery, administrated by physical education teachers, was reliable for measuring health-related components of fitness in children and adolescents in a school setting.

Strategies in intervention programmes for obese youth: implication of the age and the type of physical activities.

The aim of this study was to assess the effects of age and type of physical activity on anthropometric measures of obese youth participating in an intervention programme. Subjects included 37 obese children (12·5 ± 2·9 years). The programme consisted of a unique programme of physical activity and health education. Assessments included body mass index (BMI), body composition and ability to perform sport activities. Paired t-tests were used to assess the effects of intervention, and chi square was used to assess interaction between measures. Findings suggest significant decrease in Z-scores of BMI and an improvement in the ability to perform sport activities (P<0·05). The effectiveness of the programme has more impact on children than adolescents (P<0·05). Improvements were greater in team versus net sports (P<0·05). Results show that intervention strategies have to be different according to the age to have a favourable effect on anthropometric characteristic and the consequences of obesity childhood and adulthood. The findings suggest that the intervention programme was of greater benefit for children than adolescents.

Relationship between tactics and energy expenditure according to level of experience in badminton.

Research on racket sports has traditionally focused on expert players and has treated energy expenditure and tactics as independent factors. These prior studies could not assess how energy expenditure and tactics changed as a function of experience and skill. Here, the specific relationship between playing tactics and energy expenditure in badminton were assessed. Participants were classified into five stages of badminton experience on the basis of conative criteria: structural (physical abilities), technical (technical skills), and functional (tactics). The physical activity of 99 players (47 beginners, 15 intermediates, 30 advanced, and 7 experts) was measured using a three-axis accelerometer during a badminton set (21 points, no extra scoring). The results showed that physical activity (counts/sec.) ranged between about 115 (Stage 1) and 155 (Stage 5), and differed significantly across the conative stages. For Stages 2 and 4, defined by an increase in use of tactics, physical activity increased substantially. For Stage 3, defined by a decrease in use of tactics, physical activity decreased significantly. Thus, tactically-oriented play appears to be closely related to physical activity.

Influence of sleep timing behavior on weight status and activity patterns in adults with intellectual disabilities.

The aim was to explore the relationship between sleep habits and overweight/obesity, physical activity and sedentary behaviors in French adults with intellectual disabilities. This observational study was conducted on 570 French adults with intellectual deficiency. Sleep habits were analyzed and related to anthropometric measures, physical activity and sedentary behaviors. The study was conducted using a self-administered questionnaire. Participants completed the questionnaire during an interview with the principal investigator. Sleep timing behavior was classified into 4 sleep patterns: Early-bed/Early-rise, Early-bed/Late-rise, Late-bed/Late-rise, and Late-bed/Early-rise. Of 570 eligible participants, 61 were excluded because of missing data on age, weight or height. The number of participants identified in each of the four sleep patterns was as follows: Early-bed/Early-rise, N = 119 (23%), Early-bed/Late-rise, N = 171 (34%), Late-bed/Early-rise, N = 100 (20%), Late-bed/Late-rise N = 119 (23%). Participants who wake up earlier are more active than those who rise late (p < 0.02). Participants who slept later spent more time in sedentary activities than those in the Early rise groups (p < 0.01). The number of obese/overweight participants was also higher in Late-bed/Late rise group. Sleep behavior was associated with overweight/obesity, physical activity and sedentary behavior in adults with intellectual deficiency, independently the sleep duration. Implementing intervention or promotion programs on sleep behaviors should be considered in order to meet the objectives of promoting health on anthropometric characteristics and increased physical activity among these disabled adults.

Technical variability of the Vivago® wrist-worn accelerometer.

The aim was to assess the technical variability of a new wrist-worn accelerometer under controlled conditions with a shaker device and during normal daily physical activities (PAs). In the first experiment, 10 wrist-worn accelerometers (Vivago(®) Wellness, Paris, France) were attached to the shaker device. Variability was tested at five shaking frequencies (1.1, 2.1, 3.1, 4.1, and 10 Hz) for 10 min at each frequency. In the second experiment, 21 participants wore wrist-worn accelerometers and performed six consecutive 10-min periods of activity at increasing levels of intensity from sedentary to vigorous. Results from the first experiment show a modest inter- and intra-instrument reliability at low frequencies and that reliability improved as frequency increased. The inter-instrument coefficient of variation (CV) was 2.6-18.3%. The intra-instrument CV was 4.1-23.2%. Variability was similar in the second experiment with a CV inversely related to PA intensity. The inter- and intra-instrument CV varied from 24.2% and 19.9% for sedentary activities to 3.7% and 4.3% for vigorous PA, respectively. Results suggest that reliability was higher at high intensities, corresponding to moderate and vigorous PA, intensities generally recommended for public health purposes.

How many days of accelerometer monitoring predict weekly physical activity behaviour in obese youth?

The aim of this study was to determine the type and the number of accelerometer monitoring days needed to predict weekly sedentary behaviour and physical activity in obese youth. Fifty-three obese youth wore a triaxial accelerometer for 7 days to measure physical activity in free-living conditions. Analyses of variance for repeated measures, Intraclass coefficient (ICC) and regression linear analyses were used. Obese youth spent significantly less time in physical activity on weekends or free days compared with school days. ICC analyses indicated a minimum of 2 days is needed to estimate physical activity behaviour. ICC were 0·80 between weekly physical activity and weekdays and 0·92 between physical activity and weekend days. The model has to include a weekday and a weekend day. Using any combination of one weekday and one weekend day, the percentage of variance explained is >90%. Results indicate that 2 days of monitoring are needed to estimate the weekly physical activity behaviour in obese youth with an accelerometer. Our results also showed the importance of taking into consideration school day versus free day and weekday versus weekend day in assessing physical activity in obese youth.

Overweight in intellectually-disabled population: physical, behavioral and psychological characteristics.

Intellectually disabled (ID) people are at high risk of overweight and obesity. Prevalence and risk factors were assessed in a French population of ID adults attending specialized institutions, using a questionnaire focusing on demographic characteristics, physical activities, food habits and self-awareness about body and health. Data analysis included descriptive statistics, univariate and multivariate regression. Overall, 570 participants were included in the analysis (59% male), aged 19-59 years. The mean body mass index (BMI) was 24.9 kg/m(2); 45.6% of participants were overweight (BMI ≥ 25), including 17.2% who were obese (BMI ≥ 30). Participants practiced sports for 5.7h/week on average and were sedentary for 21.8h/week (time spent in front of some kind of screen). Most participants had food and self-care habits usually regarded as healthy. Eighty percent of them felt unhappy with their body and their physical capacities, but otherwise expressed a rather good opinion of themselves. Bivariate and multivariate analyses showed that some behavioral habits were associated with a reduced incidence of overweight and/or obesity, such as regular sport practice outside the institution, good personal body care or alcohol avoidance. The strongest risk factor was gender. Women were much more at risk than men of being overweight (53.9% versus 39.9%) and obese (28.2% versus 9.5%). Results suggest numerous ways to improve the health of institutionalized ID adults, related to sports education, nutrition and self-care, with particular attention paid to women.

Concurrent validity of the modified International Physical Activity Questionnaire for French obese adolescents.

Physical activity is an important component of a healthy lifestyle. Evaluating and promoting this activity warrants careful attention, particularly in the context of preventing obesity associated with low physical activity. The aim of the present study was to assess the concurrent validity of a modified, long, self-administered version of the International Physical Activity Questionnaire (IPAQ) using triaxial accelerometry in 56 youth with obesity. The participants' physical activity was measured with an RT3 accelerometer (objective measure) and with the International Physical Activity Questionnaire for Adolescents (IPAQ-A; subjective measure). Although the two methods were correlated strongly (r = .84), there was a significant difference between the two methods. The participants' subjective ratings on the IPAQ-A overestimated the objective measure. Although activity questionnaires are simple and widely used in assessing physical activity, alternative methods should be used when measuring physical activity in youth with obesity.

The six-minute walk test in obese youth: reproducibility, validity, and prediction equation to assess aerobic power.

PURPOSE: The aim of this study was to assess reproducibility and validity of the 6 minute walk test (6MWT) in obese youth and to develop an equation to predict aerobic power (VO(2max)). METHODS: Fifty-two girls and 45 boys, ages 7-17.8 participated in the study. Three walk tests were administered 1 week apart. Each visit corresponded to a specific test, either an incremental treadmill test, or the 6MWT. The 6MWT was performed on two occasions 1 week apart to assess reproducibility. Treadmill and walk tests were randomly assigned to avoid order effect. RESULTS: Subjects walked 689.4 ± 98.6 m on the initial 6MWT and 690.4 ± 98.2 m on the second test. Intraclass correlation coefficient was r = 0.99. The Bland and Altman method also showed good agreement between the two 6MWTs. Stepwise multiple regression determined that distance walked in 6 MWT and BMI are the most significant factors in predicting VO(2max). The prediction equation is VO2 max (ml.kg.min(-1)) = 26.9 + 0.014 × 6 MWT (meters) - 0.38 × BMI (kg/m((2))). CONCLUSIONS: In obese youth, the 6 MWT is a reproducible and valid test for assessing aerobic power. A prediction equation was developed to estimate VO(2)max, using distance walked in 6MWT and BMI. [Box: see text].

Validation of the Vivago Wrist-Worn accelerometer in the assessment of physical activity.

BACKGROUND: Most accelerometers are worn around the waist (hip or lower back) to assess habitual physical activity. Wrist-worn accelerometers may be an alternative to the waist-worn monitors and may improve compliance in studies with prolonged wear. The aim of this study was to validate the Vivago® Wrist-Worn Accelerometer at various intensities of physical activity (PA) in adults. METHODS: Twenty-one healthy adults aged 20-34 years were recruited for the study. Accelerometer data and oxygen uptake (VO2) were measured at sedentary, light, moderate and vigorous levels of PA. RESULTS: Activity categories and accelerometer counts were: sedentary, 0-15 counts·min-1; light, 16-40 counts·min-1; moderate, 41-85 counts·min-1; and vigorous activity, >; 85 counts·min-1. ANOVA repeated measures was used to determine the relationship between accelerometry data output and oxygen consumption (r = .89; p <; .001). The Bland and Altman method showed good agreement in the assessment of energy expenditure between the indirect calorimetry and the data obtained by the accelerometer. CONCLUSIONS: Results of the study suggest that the Vivago® wrist-worn accelerometer is a valid measure of PA at varying levels of intensity. The study has also defined threshold values at 4 intensities and hence te Vivago® accelerometer may be used to quantify PA in free living conditions among adults. This device has possible application in treating a variety of important health concerns.

A conative educational model for an intervention program in obese youth.

BACKGROUND: Obesity in children has increased in recent years throughout the world and is associated with adverse health consequences. Early interventions, including appropriate pedagogy strategies, are important for a successful intervention program. The aim of this study was to assess changes in body mass index, the ability to perform sport activities, behavior in the classroom and academic performance following one year of a health-wellness intervention program in obese youth. METHODS: The CEMHaVi program included 37 obese children (19 girls and 18 boys). Participants received an intervention program consisting of physical activity and health education. Assessment included body mass index, academic performance, classroom performance and ability to perform sport activities. Paired t tests were used to assess the effects of intervention, and chi square was used to assess inter-action between measures. RESULTS: Findings of the study suggest significant decrease in Z scores of Body Mass Index and an improvement of academic performance, classroom behavior and the ability to perform sport activities (p < 0.05). Chi square testing showed significant positive inter-actions between body mass index, classroom behavior and academic performance. CONCLUSIONS: Results following year one of CEMHaVi showed that a program of physical activity and health education had positive effects on obesity, behavior in the classroom and the ability to perform sport activities in obese adolescents. Significant inter-action in changes between variables was observed. Findings are important for designing intervention models to improve health in obese youth.

Comparison of two ActiGraph accelerometer generations in the assessment of physical activity in free living conditions.

BACKGROUND: The aim of this study was to compare physical activity measured using GT1M ActiGraph and GT3X ActiGraph accelerometers in free living conditions. FINDINGS: Twenty-five adults wore GT1M and GT3X Actigraph accelerometers simultaneously during a typical weekday of activity. Data were uploaded from the monitor to a computer at the end of test (one day). Previously established thresholds were used for defining time spent at each level of physical activity, physical activity was assessed at varying intensities comparing data from the two accelerometers by ANOVA and Bland and Altman statistical analysis. The concordance correlation coefficient between accelerometers at each intensity level was 0.99. There were no significant differences between accelerometers at any of the activity levels. Differences between data obtained in minutes with the GT1M accelerometer and the GT3X monitor were to 0.56, 0.36, 0.52 and 0.44% for sedentary, light, moderate and vigorous, respectively. The Bland and Altman method showed good agreement between data obtained for the two accelerometers. CONCLUSIONS: Findings suggest that the two accelerometers provided similar results and therefore the GT3X may be used in clinical and epidemiological studies without additional calibration or validation studies.

Effects of a multidisciplinary rehabilitation program on pediatric obesity: the CEMHaVi program.

The objective of this study is to assess the effects of the unique 1-year health-wellness program of exercise and health education for obese youth on body mass index (BMI) and blood pressure. The CEMHaVi program included 74 obese children. Participants, 19 girls and 18 boys, and controls, 17 girls and 20 boys, were assigned to treatment. The treatment participants were compared with a group who chose not to participate. Treatment consisted of a unique program of physical activity that emphasized playing games. Activity sessions were offered once per week, 2 h each session, for 12 months. Physical activity was complemented with health education. Controls received only the normal care of a physician in pediatrics. Physical and physiological measures were assessed before and after intervention. Findings of the study showed a significant difference in BMI between treatment and control participants (P<0.05). BMI decreased in the treatment group and increased in controls. There were no significant differences in blood pressure. In conclusion, results of the study suggest that a unique program of exercise and health education had beneficial effects on BMI in obese youth after 1 year. The feasibility of a beneficial lifestyle intervention program is encouraging.