bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of Single-Leg Drop-Landing Exercise from Different Heights on Skeletal Adaptations in Prepubertal Girls: A Randomized Controlled Study
Authors: Wiebe Peter N. , Blimkie Cameron J. R. , Farpour-Lambert Nathalie , Briody Julie , Marsh Damian , Kemp Allan , Cowell Chris , Howman-Giles Robert
Published: August 2016

Few studies have explored osteogenic potential of prepubertal populations. We conducted a 28-week school-based exercise trial of single-leg drop-landing exercise with 42 prepubertal girls (6 to 10 yrs) randomly assigned to control (C), low-drop (LD) or high-drop (HD) exercise groups. The latter two groups performed single-leg drop-landings (3 sessions/wk−1 and 50 landings/session−1) from 14cm(LD) and 28cm(HD) using the nondominant leg. Osteogenic responses were assessed using Dual Energy X-ray Absorptiometry (DXA). Single-leg peak ground-reaction impact forces (PGRIF) in a subsample ranged from 2.5 to 4.4 × body-weight (BW). No differences (p > .05) were observed among groups at baseline for age, stature, lean tissue mass (LTM), leisure time physical activity, or average daily calcium intake. After adjusting for covariates of body mass, fat mass and LTM, no differences were found in bone mineral measures or site-specific bone mineral density (BMD) at the hip and lower leg among exercise or control groups. Combining data from both exercise groups failed to produce differences in bone properties when compared with the control group. No changes were apparent for between-leg differences from baseline to posttraining. In contrast to some reports, our findings suggest that strictly controlled unimodal, unidirectional single-leg drop-landing exercises involving low-moderate peak ground-reaction impact forces are not osteogenic in the developing prepubertal female skeleton.
Lung Function Increases with Increasing Level of Physical Activity in School Children
Authors: Berntsen Sveinung , Wisløff Torbjørn , Nafstad Per , Nystad Wenche
Published: August 2016

Little is known about the association between physical activity and lung function in childhood. We conducted a survey including parental reports of the child’s participation in physical activity and measurements of lung function. The associations between physical activity and lung function were estimated by linear regression analysis adjusting for potential confounders in 2,537 children (9 to 10 years). Using the linear model in exploring the effect of physical activity on lung function with those who were physical active less than once a week as the reference category, showed that forced expiratory volume in 1 s (FEV1) was highest among those who were physical active ≥ 4 times a week also when adjusting for potential confounders (p = .02). FEV1 increased with 70 ml. A similar pattern was present for forced vital capacity (FVC; p = .002). The present study suggested that lung function was highest in highly physical active children age 9 to 10 years. The implications are that exercise may influence lung function, but these findings need to be confirmed using a longitudinal study design.
Skin Microvascular Reactivity in Children and Adolescents with Type 1 Diabetes in Relation to Levels of Physical Activity and Aerobic Fitness
Authors: Roche Denise M. , Edmunds Sarah , Cable Tim , Didi Mo , Stratton Gareth
Published: August 2016

No studies to date have evaluated the relationship between exercise and microvascular function in youth with type 1 diabetes mellitus (T1DM). Twenty-nine complication free children and adolescents with T1DM were assessed for skin microvascular reactivity, aerobic fitness (VO2peak) and physical activity. VO2peak but not physical activity was significantly and independently associated with maximal hyperemia of the skin microcirculation (p < .01). No significant associations were found between venoarte-riolar reflex (VAR) vasoconstriction and VO2peak or physical activity. Aerobic fitness may be an important indicator or mediator of effective microvascular endothelial function in youth with T1DM.
The Relationship Between Physical Activity and the Metabolic Syndrome Score in Children
Authors: DuBose Katrina D. , McKune Andrew J. , Brophy Patricia , Geyer Gabriel , Hickner Robert C.
Published: August 2016

The relationship between physical activity levels and the metabolic syndrome (MetSyn) score was examined in 72 boys and girls (9.5 ± 1.2 years). A fasting blood draw was obtained; waist circumference and blood pressure measured, and an accelerometer was worn for 5 days. Established cut points were used to estimate time spent in moderate, vigorous, moderate-to-vigorous (MVPA), and total physical activity. A continuous MetSyn score was created from blood pressure, waist circumference, high-density-lipoprotein, triglyceride, and glucose values. Regression analysis was used to examine the relationship between physical activity levels, the MetSyn score, and its related components. Logistic regression was used to examine the association between meeting physical activity recommendations, the MetSyn score, and its related components. All analyses were controlled for body mass index group, age, sex, and race. Time spent in different physical activity levels or meeting physical activity recommendations (OR: 0.87, 95%CI: 0.69–1.09) was not related with the MetSyn score after controlling for potential confounders (p > .05). Moderate physical activity, MVPA, and meeting physical activity recommendations were related to a lower diastolic blood pressure (p < .05). No other relationships were observed (p > .05). While physical activity participation was not related with the MetSyn, lower diastolic blood pressure values were related to higher physical activity levels.
Oxygen Uptake Kinetics in Children and Adolescents: A Review
Authors: Armstrong Neil , Barker Alan R.
Published: August 2016

The pulmonary oxygen uptake (pVO2) kinetic response at the onset of exercise provides a noninvasive window into the metabolic activity of the muscle and a valuable means of increasing our understanding of developmental muscle metabolism. However, to date only limited research has been devoted to investigating the pVO2 kinetic response during exercise in children and adolescents. From the rigorous studies that have been conducted, both age- and sex-related differences have been identified. Specifically, children display a faster exponential rise in the phase II pVO2 kinetics, which are purported to reflect the rise in muscle O2 consumption, during moderate, heavy and very heavy intensity exercise compared with adults. Furthermore, for heavy and very heavy exercise, the O2 cost of exercise is higher for the exponential phase and the magnitude of the pVO2 slow component is smaller in young children. Sex-related differences have been identified during heavy, but not moderate exercise, with prepubertal boys displaying a faster exponential phase II pVO2 kinetic response and a smaller pVO2 slow component compared with prepubertal girls. The mechanisms underlying these differences are currently poorly understood, and form the basis for future research in this area. However, it is hypothesized that an age-related modulation of the muscle phosphate feedback controllers to signal an increased rate of oxidative phosphorylation and/or altered muscle fiber type recruitment strategies have the potential to play an important role. Overall, the data support the view that at the onset of exercise children have an enhanced potential for oxidative metabolism in the myocyte compared with adults.
Personal Characteristics and Demographic Factors Associated with Objectively Measured Physical Activity in Children Attending Preschool
Authors: Grøntved Anders , Pedersen Grete Skøtt , Andersen Lars Bo , Kristensen Peter Lund , Møller Niels Christian , Froberg Karsten
Published: August 2016

Independent associations between personal- and demographic characteristics and physical activity in 3–6 year old children attending preschool were identified in this study. Boys spent a larger proportion of the time on moderate-and-vigorous physical activity (MVPA; p < .001) and had a higher total physical activity level compared with girls (p < .001). The 3–4 year old children spent less time on MVPA and had a lower total physical activity level compared with both 4–5 (p < .01) and 5–6 year old children (p < .001). The individual preschool, gender and age of preschool children were strong predictors of physical activity (R2-total model=(0.36−0.39)) during preschool attendance.
Allometric Associations between Body Size, Shape, and Physical Performance of Greek Children
Authors: Nevill Alan , Tsiotra Georgia , Tsimeas Panagiotis , Koutedakis Yiannis
Published: August 2016

We adopted allometric models to identify the most appropriate body size/shape characteristics associated with physical performance activities of Greek school children. Children underwent assessments for aerobic and anaerobic fitness, flexibility and hand-grip strength. Results suggest that the inverse Ponderal index and not BMI is the most appropriate body-shape indicator associated with running and jumping activities. Height was negatively associated with flexibility, but both height and weight were positively associated with hand-grip strength. In conclusion, allometric models provide a valuable insight into the most appropriate body size and shape characteristics associated with children’s physical performances and at the same time ensure valid inference when investigating group/population differences (e.g., between gender and maturation status).
Feasibility of a Home-Delivered Internet Obesity Prevention Program for Fourth-Grade Students
Authors: Owens Scott , Lambert Laurel , McDonough Suzanne , Green Kenneth , Loftin Mark
Published: August 2016

This pilot study examined the feasibility of an interactive obesity prevention program delivered to a class of fourth-grade students utilizing daily e-mail messages sent to the students’ home computers. The study involved a single intact class of 22 students, 17 (77%) of whom submitted parental permission documentation and received e-mail messages each school day over the course of one month. Concerns regarding Internet safety and children’s use of e-mail were addressed fairly easily. Cost/benefit issues for the school did not seem prohibitive. Providing e-mail access to students without a home computer was accomplished by loaning them personal digital assistant (PDA) devices. In larger interventions, loaning PDAs is probably not feasible economically, although cell phones may be an acceptable alternative. It was concluded that this type of interactive obesity prevention program is feasible from most perspectives. Data from a larger scale effectiveness study is still needed.
Body Composition of Elite, Eumenorrheic and Amenorrheic, Adolescent Cross-Country Runners
Authors: Bonis Marc , Loftin Mark , Speaker Richard , Kontos Anthony
Published: August 2016

The purpose of the study was to investigate the seasonal relationship of athletic amenorrhea and body composition in elite, adolescent, cross-country runners. The participants consisted of 28 female adolescent cross-country runners (mean age ± SD = 15.4 ± 1.5 years); 17 eumenorrheics and 11 amenorrheics. The participants’ body composition was measured pre- and postseason using dual-energy X-ray Absorptiometer (DXA). The eumenorrheics’ postseason BMD was significantly greater than the amenorrheics’ postseason BMD (F(1,54) = 16.22, p < .05, partial η2 = .231). The eumenorrheics’ postseason bodyweight (F(1,54) = 7.65, p < .05, partial η2 = .124), BF (F(1,54) = 8.56, p < .05, partial η2 = .137), and BMC (F(1,54) = 8.52, p < .05, partial η2 = .136) were significantly greater than the amenorrheic subgroup. There was also a significant seasonal increase in BMD (t(27) = –4.01, p < .05) for the overall group and the eumenorrheic subgroup (t(16) = –3.90, p < .05). Bodyweight best predicted BMD (F(1,26) = 46.434, p < .05, R2 = .641). In the study, athletic amenorrhea was highly associated with lower levels of BMD in the participants, and crosscountry running was highly associated with increased BMD.
Reliability and Validity of the Modified Chinese Version of the Children’s Leisure Activities Study Survey (CLASS) Questionnaire in Assessing Physical Activity among Hong Kong Children
Authors: Huang Y.J. , Wong Stephen H.S. , Salmon Jo
Published: August 2016

This study aimed to examine the reliability and validity of the modified Children’s Leisure Activities Study Survey (CLASS) Chinese-version questionnaire in assessing physical activity among Hong Kong Chinese Children. Test-retest reliability was examined in 84 boys and 136 girls aged 9–12 years by comparing data from two administrations of the survey conducted one week apart. Validity was determined by comparing data from the second administration with accelerometer estimates. The results suggested that the questionnaire provided reliable and valid estimates in overall physical activity patterns in Hong Kong Chinese children. However, substantial overestimation was observed in vigorous activity.
Coaching Behaviors, Motivational Climate, and Psychosocial Outcomes among Female Adolescent Athletes
Authors: Weiss Maureen R. , Amorose Anthony J. , Wilko Anna Marie
Published: August 2016

Based on Harter’s (12,13) competence motivation theory, this study examined the relationship of coaches’ performance feedback and motivational climate with female athletes’ perceived competence, enjoyment, and intrinsic motivation. Female adolescent soccer players (N = 141) completed measures of relevant constructs toward the latter part of their season. Canonical correlation analysis revealed that athletes’ perceptions of greater positive and informational feedback given by coaches in response to successful performance attempts, greater emphasis placed on a mastery climate, and less emphasis placed on a performance climate, were significantly related to greater ability perceptions, enjoyment, and intrinsic motivation. Exploratory analyses also showed that the relationship between feedback and the psychosocial outcomes may vary as a function of the perceived motivational climate. Overall, these results suggest that coaching feedback and motivational climate are important contributors to explaining adolescent females’ continued motivation to participate in sport.
The Assessment of Physical Activity and Nutrition in Home Schooled Versus Public Schooled Children
Authors: Long Douglas E. , Gaetke Lisa M. , Perry Stephen D. , Abel Mark G. , Clasey Jody L.
Published: August 2016

The purpose of this study was to descriptively compare the physical activity and dietary intake of public school (PSC) versus home schooled children (HSC). Potential parental and home influences were also examined. Thirty six matched pairs of public school-home school children aged 7–11 years participated in this study. Each participant wore an activity monitor and recorded their dietary intake concurrently for seven consecutive days. PSC had significantly more total and weekday steps, and spent more time in moderate-to-vigorous physical activity compared with HSC. There were no differences in dietary intake between the two groups. These results suggest differences in physical activity between PSC and HSC and encourage further study of public and home school environments, in relation to the obesity epidemic.
Effect of Wrestling Exercise on Oxidative DNA Damage, Nitric Oxide Level and Paraoxonase Activity in Adolescent Boys
Authors: Hamurcu Zuhal , Saritas Nazmi , Baskol Gulden , Akpinar Nese
Published: August 2016

The objective of the current study is to determine the effects of regular wrestling exercise oxidative DNA damage and antioxidant parameters. The findings of the current study have shown that 8-hydroxy-2’-deoxyguanosine (8-OHdG) obtained from wrestlers in basal status were significantly lower than those of sedentary (p = .001). In contrast, Nitric oxide (NO) and Paraoxonase-1 (PON1) were remarkably higher in wrestlers in basal status than those of sedentary (respectively, p = .001, p = .024). While the NO of wrestlers increased immediately after a 1.5-h exercise compared with those before exercise (p = .002), no differences was found between before and immediately after a 1.5-h exercise in 8-OHdG and PON1 (respectively, p = .777, p = .408).Statistically significant correlations were found between the NO and PON1 in the wrestlers in basal status (r = .671, p = .002). In conclusion, our study suggests that wrestling exercise for a healthy life is important in that it reduces DNA damage as well as enhancing antioxidant parameters.
ACE I/D Genotype, Habitual Physical Activity, and Blood Pressure in Children
Authors: Sarzynski Mark A. , Eisenmann Joey C. , Welk Gregory J. , Tucker Jared , Glenn Kim , Rothschild Max , Heelan Kate
Published: August 2016

The present study examined the association between the angiotensin converting enzyme (ACE) insertion/deletion (I/D) polymorphism, physical activity, and resting blood pressure (BP) in a sample of 132 children (48.4% female). Children attaining 60 min/day of moderate-to-vigorous physical activity (MVPA) possessed lower % body fat (29% vs 24%, p < .05). Resting BP did not significantly differ between genotypes. Furthermore, partial correlations between MVPA and BP were low and did not vary by ACE genotype. Thus, the ACE I/D genotype is not associated with BP and does not modify the relationship between physical activity and BP in this sample of children.
Maternal Prepregnancy Overweight and Offspring Fatness and Blood Pressure: Role of Physical Activity
Authors: Eisenman Joey C. , Sarzynski Mark A. , Tucker Jerod , Heelan Kate A.
Published: August 2016

The purpose of this study was to examine if offspring physical activity may affect the relationship between maternal overweight and offspring fatness and blood pressure (BP). Subjects included 144 maternal-child pairs (n = 74 boys and 70 girls, mean age = 7.3 yrs). Maternal prepregnancy BMI was determined by self-report. Offspring characteristics included resting systolic and diastolic BP, body fatness by dual energy x-ray absorbtiometry, and moderate-to-vigorous physical activity (MVPA) using the Actigraph accelerometer. Children whose mothers were overweight or obese prepregnancy (Prepreg OW) were significantly larger and fatter than children from mothers with a normal prepregnancy BMI (Prepreg NORM). Prepreg OW children also had higher mean arterial pressure than Prepreg NORM children. BP values were not different across maternal Prepreg BMI/MVPA groups. Percent fat was significantly different across Prepreg BMI/MVPA groups. Prepreg OW children that did not meet the daily recommended value of MVPA were the fattest. Prepreg OW children that attained 360 min of MVPA/day had a mean percent body fat that was similar to Prepreg NORM children of either MVPA group.
Describing Patterns of Physical Activity in Adolescents Using Global Positioning Systems and Accelerometry
Authors: Maddison Ralph , Jiang Yannan , Hoorn Stephen Vander , Exeter Daniel , Mhurchu Cliona Ni , Dorey Enid
Published: August 2016

This study aimed to describe the location and intensity of free-living physical activity in New Zealand adolescents during weekdays and weekend days using Global Positioning Systems (GPS), accelerometry, and Geographical Information Systems (GIS). Participants (n = 79) aged 12–17 years (M = 14.5, SD 1.6) recruited from two large metropolitan high schools each wore a GPS watch and an accelerometer for four consecutive days. GPS and accelerometer data were integrated with GIS software to map the main locations of each participant’s episodes of moderate-vigorous physical activity. On average participants performed 74 (SD 36) minutes of moderate and 7.5 (SD 8) minutes of vigorous activity per day, which on weekdays was most likely to occur within a 1 km radius of their school or 150 meters of their home environment. On weekends physical activity patterns were more disparate and took place outside of the home environment. Example maps were generated to display the location of moderate to vigorous activity for weekdays and weekends.
Is the Relationship Between Sprinting and Maximal Aerobic Speeds in Young Soccer Players Affected by Maturation?
Authors: Mendez-Villanueva Alberto , Buchheit Martin , Kuitunen Sami , Poon Tsz Kit , Simpson Ben , Peltola Esa
Published: August 2016

The purpose of this study was to investigate the relationship between maximal sprinting (MSS) and aerobic (MAS) speeds in a cohort of highly-trained young male soccer players with the influence of body mass controlled for using allometric scaling. MSS and MAS were obtained in 14 pre-age at peak height velocity (APHV) players (12.3 ± 0.7 years), 21 circum-APHV players (14.3 ± 0.9 year) and 26 post-APHV players (16.9 ± 0.7 years). The three groups showed similar positive correlations between MSS and MAS (r = 0.73 to 0.52; p < .01). In conclusion, our results suggest that the relationship between MSS and MAS is not affected by maturation.
Effects of a School-Based Physical Activity Program on Physical and Psychosocial Quality of Life in Elementary School Children: A Cluster-Randomized Trial
Authors: Hartmann Tim , Zahner Lukas , Pühse Uwe , Puder Jardena J. , Kriemler Susi
Published: August 2016

The present study tested the effect of a school-based physical activity (PA) program on quality of life (QoL) in 540 elementary school children. First and fifth graders were randomly assigned to a PA program or a no-PA control condition during one academic year. QoL was assessed by the Child Health Questionnaire at baseline and postintervention. Based on mixed linear model analyses, physical QoL in first graders and physical and psychosocial QoL in fifth graders were not affected by the intervention. In first graders, the PA intervention had a positive impact on psychosocial QoL (effect size [d], 0.32; p < .05). Subpopulation analyses revealed that this effect was caused by an effect in urban (effect size [d], 0.38; p < .05) and overweight first graders (effect size [d], 0.45; p < .05). In conclusion, a school-based PA intervention had little effect on QoL in elementary school children.
Difference Between Self-Reported and Accelerometer Measured Moderate-to-Vigorous Physical Activity in Youth
Authors: LeBlanc Allana G.W. , Janssen Ian
Published: August 2016

We examined differences between objective (accelerometer) and subjective (self-report) measures of moderate-to-vigorous physical activity (MVPA) in youth. Participants included 2761 youth aged 12–19 years. Within each sex and race group, objective and self-reported measures of MVPA were poorly correlated (R2 = .01–.10). Self-reported MVPA values were higher than objective values (median: 42.4 vs. 15.0 min/d). 65.4% of participants over-reported their MVPA by 35 min/d. The difference between self-reported and objective measures was not influenced by sex, age, or race. There was, however, a systematic difference such that inactive participants over-reported their MVPA to the greatest extent.
The Effect of Active Video Gaming on Children’s Physical Activity, Behavior Preferences and Body Composition
Authors: Graves Lee E.F. , Ridgers Nicola D. , Atkinson Greg , Stratton Gareth
Published: August 2016

Active video game interventions typically provide children a single game that may become unappealing. A peripheral device (jOG) encourages step-powered gaming on multiple games. This trial evaluated the effect of jOG on children’s objectively measured PA, body fat and self-reported behaviors. 42 of 58 eligible children (8–10 y) randomly assigned to an intervention (jOG) or control (CON) completed the trial. Intervention children received two jOG devices for home use. Analyses of covariance compared the intervention effect at 6 and 12 weeks from baseline. No differences were found between groups for counts per minute (CPM; primary outcome) at 6 and 12 weeks (p > .05). Active video gaming increased (adjusted change 0.95 (95% CI 0.25, 1.65) h·d−1, p<.01) and sedentary video gaming decreased (-0.34 (-1.24, 0.56) h·d−1, p > .05) at 6 weeks relative to CON. No body fat changes were observed between groups. Targeted changes in video game use did not positively affect PA. Larger trials are needed to verify the impact of active video games on children’s PA and health.
Exercise Protocols to Estimate Fatmax and Maximal Fat Oxidation in Children
Authors: Zakrzewski Julia , Tolfrey Keith
Published: August 2016

Consensus on the exercise protocol used to measure Fatmax (exercise intensity corresponding to maximum fat oxidation (MFO)) in children has not been reached. The present study compared Fatmax estimated using the 3 min incremental cycling protocol (3-INC) and a protocol consisting of several 10 min constant work rate exercise bouts (10-CWR) in 26 prepubertal children. Group Fatmax values were the same for 3-INC and 10-CWR (55% VO2peak) and 95% limits of agreement (LoA) were ± 7% VO2peak. Group MFO values were similar between protocols, although 95% LoA were -94 to 113 mg·min−1. While 3-INC provides a valid estimation of Fatmax compared with 10-CWR, caution should be exercised when estimating MFO in prepubertal children.
Potentiation and Recovery Following Low- and High-Speed Isokinetic Contractions in Boys
Authors: Chaouachi Anis , Haddad Monoem , Castagna Carlo , Wong Del P. , Kaouech Fathi , Chamari Karim , Behm David G.
Published: August 2016

The objective of this study was to examine the response and recovery to a single set of maximal, low and high angular velocity isokinetic leg extension-flexion contractions with boys. Sixteen boys (11–14 yrs) performed 10 isokinetic contractions at 60°.s−1 (Isok60) and 300°.s−1 (Isok300). Three contractions at both velocities, blood lactate and ratings of perceived exertion were monitored pretest and at 2, 3, 4, and 5 min of recovery (RI). Participants were tested in a random counterbalanced order for each velocity and recovery period. Only a single contraction velocity (300°.s−1 or 60°.s−1) was tested during recovery at each session to remove confounding influences between the recovery intervals. Recovery results showed no change in quadriceps’ power at 300°.s−1, quadriceps’ power, work and torque at 60°.s−1 and hamstrings’ power and work with 60°.s−1. There was an increase during the 2 min RI in hamstrings’ power, work and torque and quadriceps’
The Effect of Peer Influence on the Amount of Physical Activity Performed in 8- to 12-Year-Old Boys
Authors: Rittenhouse Melissa , Salvy Sarah-Jeanne , Barkley Jacob E.
Published: August 2016

The purpose of this study was to determine the amount of physical and sedentary activity normal-weight and at-risk-for/overweight boys perform when alone, with a peer of similar weight and with a peer of different weight. Participants included boys, ages 8–12 years, classified as either normal-weight (<85th BMI percentile; N = 12) or at-risk-for/overweight (<85th BMI percentile; N = 12). At-risk-for/overweight boys allocated a greater amount of time to sedentary activities and accumulated fewer accelerometer counts than normal-weight boys in the alone condition. Once paired with a peer of either similar or different weight there were no differences between groups. These results indicate the presence of an unknown peer has a positive effect on at-risk-for/overweight children’s physical activity behavior.
The Influence of Distance to School on the Associations Between Active Commuting and Physical Activity
Authors: Panter Jenna , Jones Andrew , Van Sluijs Esther , Griffin Simon
Published: August 2016

The purpose of this cross-sectional study was to examine the associations between active commuting behavior, levels of physical activity and distance to school in 9–10 year old children. Participants were children (n = 1824) who took part in the SPEEDY study (Sport, Physical activity and Eating behavior: Environmental Determinants in Young people). For both boys and girls, significant positive associations were observed between walking to school and physical activity and moderate-to-vigorous physical activity during weekday journey times (8–9am and 3–4pm), and the size of association also became stronger with increasing distance from school. Promotion of active commuting to school might be an important way to increase levels of physical activity in school children.
The Influence of Physical Activity on Cardiometabolic Biomarkers in Youths: A Review
Authors: Gutin Bernard , Owens Scott
Published: August 2016

The purposes of this article were to (1): review recent studies of relations between physical activity and cardiometabolic biomarkers of youths (2); highlight areas in which additional research is needed; and (3) make recommendations for preventive interventions. Observational studies show that youths who engage in high amounts of moderate-vigorous physical activity display a more favorable cardiometabolic biomarker profile than youths who engage in lesser amounts of moderate-vigorous physical activity. Intervention studies in obese youths show that favorable changes in biomarkers are produced by moderate-vigorous physical activity doses of 150–180 min/week. However, for nonobese youths, intervention studies suggest that such doses are not effective; higher moderate-vigorous physical activity doses of approximately 300 min/week seem necessary. Continuing a physically active lifestyle from childhood into the adult years will enable people to maintain less end-organ damage and lower rates of morbidity and mortality from cardiovascular disease and type 2 diabetes.
Active Commuting and Physical Activity in Adolescents From Europe: Results From the HELENA Study
Authors: ChiMón Palma , Ortega Francisco B. , Ruiz Jonatan R. , De Bourdeaudhuij Ilse , Martínez-Gómez David , Vicente-Rodriguez Germán , Widhalm Kurt , Molnar Dénes , Gottrand Frédéric , González-Gross Marcela , Ward Dianne S. , Moreno Luis A. , Castillo Manuel J. , Sjöström Michael
Published: August 2016

Chillón and Ruiz are with the Department of Physical Education and Sport, University of Granada, Spain. Chillón and Ward are with the Center for Health Promotion and Disease Prevention, University of North Carolina at Chapel Hill, NC, USA. Ortega, Ruiz and Sjöström are with the Unit for Preventive Nutrition, Department of Biosciences and Nutrition, Karolinska Institutet, Sweden. Ortega and Castillo are with the Department of Medical Physiology, University of Granada, Spain. De Bourdeaudhuij is with the Department of Movement and Sport Sciences, Ghent University, Belgium. Martínez-Gómez is with the Immunonutrition Research Group, Department of Metabolism and Nutrition, ICTAN, Spanish National Research Council (CSIC), Spain. Vicente-Rodríguez and Moreno are with Growth, Exercise, Nutrition and Development (GENUD) Research Group, Universidad de Zaragoza, Spain. Widhalm is with the Department of Paediatrics, Division of Clinical Nutrition, Medical University of Vienna, Austria. Molnar is with the Deprtment of Paediatrics, Clinical Center, University of Pécs, Hungary. Gottrand is with Inserm U995, University Lille2 and CIC-9301-CH&U-Inserm, University Hospital of Lille, France. González-Gross is with the Department of Health and Human Performance, Universidad Politécnica de Madrid, Spain.
Physical Activity During Soccer and Its Contribution to Physical Activity Recommendations in Normal Weight and Overweight Children
Authors: Sacheck Jennifer M. , Nelson Tara , Ficker Laura , Kafka Tamar , Kuder Julia , Economos Christina D.
Published: August 2016

Amid the childhood obesity epidemic, understanding how organized sports participation contributes to meeting physical activity recommendations in children is important. Anthropometrics were measured in children (n = 111; 68% female, 9.1 ± 0.8yr) before one 50-min soccer match. Time spent at different physical activity intensity levels was examined using Actigraph accelerometers. 49% of the match time was spent in sedentary activity (25.4 ± 5.7 min), while 33% of the match (16.9 ± 4.7 min) was spent in moderate-to-vigorous activity (MVPA; p < .001). 22.5% of the children were overweight/obese and spent more time in sedentary activity (+3.2 ± 1.2 min; p < .05) and less time in MVPA (-3.0 ± 1.0 min; p < .01) compared with the normal weight children. These data demonstrate that playing an organized sport such as soccer only meets a portion (~25%) of the 60 min of MVPA recommended and even less of this recommendation is met by overweight/obese children.
Optimizing the Wingate Anaerobic Cycling Test for Youth With Juvenile Idiopathic Arthritis
Authors: Obeid Joyce , Larché Maggie J. , Timmons Brian W.
Published: August 2016

The Wingate Anaerobic Test (WAnT) can assess muscle function in youth with juvenile idiopathic arthritis (JIA). Our objective was to compare peak power (PP) and mean power (MP) when the WAnT is performed with a standard vs. an optimized braking force. Eight patients with JIA between the ages of 8 and 18 participated in two sessions. Optimal braking force was determined with a series of 15-s force-velocity tests performed against braking forces ranging from 3.5 to 8.5% of body weight. Participants then performed two randomized WAnTs against the standard (4.5%) and optimal braking forces. PP tended to be greater in the optimized vs. standard WAnT (12.5 ± 2.6 vs. 10.8 ± 1.0 W/kg, respectively; p =.07). No differences were observed for MP (standard: 6.2 ± 0.9 vs. optimized: 6.2 ± 1.1 W/kg; p = .9). Optimization of the WAnT tended to increase PP by 10–28% in youth with JIA.
Relationship Between Active School Transport and Body Mass Index in Grades-4-to-6 Children
Authors: Larouche Richard , Lloyd Meghann , Knight Emily , Tremblay Mark S.
Published: August 2016

The current investigation assessed the impact of active school transportation (AST) on average daily step counts, body mass index (BMI) and waist circumference in 315 children in Grades 4–6 who participated to Cycle 2 of the Canadian Assessment of Physical Literacy (CAPL) pilot testing. T-tests revealed a significant association between AST and lower BMI values (18.7 ± 3.3 vs. 19.9 ± 3.8 kg/m2). The active commuters accumulated an average of 662 more steps per day, and their waist circumference was lower by an average of 3.1 cm, but these differences were not statistically significant. ANCOVA analyses controlling for age and step counts, found trends toward lower BMI and waist circumference values among the active commuters. These results suggest that AST may be a valid strategy to prevent childhood obesity; further research is needed to determine more precisely the impact of AST on body composition, and the direction of the relationship.
The Influence of Body Composition on Youth Throwing Kinetics
Authors: Garner John C. , MacDonald Chris , Wade Chip , Johnson Andrea , Ford M. Allison
Published: August 2016

The primary objective of this study was to investigate the influence of segmental mass and body composition on the upper extremity biomechanics of overweight youth participating in baseball activities. The study used a regression framework to investigate the relationship between whole body, throwing arm segmental mass and body composition measures to kinetic variables about the shoulder and elbow. The multivariate regression results indicated a strong positive significant relationship between each of the mass variables to that of the moment variables about the shoulder and elbow. Participants who had a greater percentage of fat mass produced greater injury correlated moments about the shoulder and elbow.
Convergent Validity of a Piezoelectric Pedometer and an Omnidirectional Accelerometer for Measuring Children’s Physical Activity
Authors: Duncan Scott , White Kate , Sa’ulilo Losi , Schofield Grant
Published: August 2016

The aim of this study was to assess the convergent validity of a new piezoelectric pedometer and an omnidirectional accelerometer for assessing children’s time spent in moderate to vigorous physical activity (MVPA). A total of 114 children (51 boys, 63 girls) aged 5–11 years wore a sealed NL-1000 piezoelectric pedometer (New Lifestyles Inc, Lee’s Summit, MO) and an Actical accelerometer (Mini Mitter, Bend, OR) over one school day. The NL-1000 pedometers were randomized to one of two manual intensity thresholds used to define MVPA (1): Level 3 = 2.9 metabolic equivalent test (MET) and (2) Level 4 = 3.6 MET. Compared with the Actical, the NL-1000 underestimated the time spent in MVPA by 37% and 45% at intensity levels 3 and 4, respectively. In addition, the 95% limits of agreement were wide at both intensity levels (level 3 = -144%, 70%; level 4 = -135%, 45%), indicating a low level of precision.
The Interaction of Obesity and Puberty on Substrate Utilization During Exercise: A Gender Comparison
Authors: McMurray Robert G. , Hosick Peter A.
Published: August 2016

The study evaluated the interactions of puberty and obesity on substrate oxidation of overweight girls (n = 38) and boys (N = 35; BMI > 85th percentile) matched for gender, age, and puberty (pre/pubertal) with normal weight girls and boys. Metabolic rates (VO2) were obtained during rest and at 4, 5.6 and 8 k/h. Carbohydrate oxidation rates (mg/kgFFM/min) adjusted for % predicted VO2max, were higher for prepubertal OW children than pubertal children (p < .03). Fat oxidation rates were higher for NW prepubertal boys compared with other boys. Results indicate that OW children, regardless of gender or pubertal status, increase their carbohydrate oxidation rate to compensate for higher than normal metabolic rates. The effects of obesity on the substrate use is marginally related to puberty.
Objective Measurement of Habitual Sedentary Behavior in Pre-School Children: Comparison of Activpal With Actigraph Monitors
Authors: Martin Anne , McNeill Mhairi , Penpraze Victoria , Dall Philippa , Granat Malcolm , Paton James Y. , Reilly John J.
Published: August 2016

The Actigraph is well established for measurement of both physical activity and sedentary behavior in children. The activPAL is being used increasingly in children, though with no published evidence on its use in free-living children to date. The present study compared the two monitors in preschool children. Children (n 23) wore both monitors simultaneously during waking hours for 5.6d and 10h/d. Daily mean percentage of time sedentary (nontranslocation of the trunk) was 74.6 (SD for the Actigraph and 78.9 (SD 4.3) for activPAL. Daily mean percentage of time physically active (light intensity physical activity plus MVPA) was 25.4 (SD for the Actigraph and 21.1 (SD 4.3) for the activPAL. Bland-Altman tests and paired t tests suggested small but statistically significant differences between the two monitors. Actigraph and activPAL estimates of sedentary behavior and physical activity in young children are similar at a group level.
Home, School, and Neighborhood Environment Factors and Youth Physical Activity
Authors: Millstein Rachel A. , Strobel Joe , Kerr Jacqueline , Sallis James F. , Norman Gregory J. , Durant Nefertiti , Harris Sion , Saelens Brian E.
Published: August 2016

This study examined the contributions of home, school, and neighborhood factors related to youth physical activity (PA). Adolescents (ages 12–18; N = 137) and parents of younger children (ages 5–11; N = 104) from three US metropolitan areas completed surveys. Youth PA was estimated from six items assessing overall physical activity. Bivariate analyses between environment factors and PA
Promoting Fundamental Movement Skill Development and Physical Activity in Early Childhood Settings: A Cluster Randomized Controlled Trial
Authors: Jones Rachel A. , Riethmuller Annaleise , Hesketh Kylie , Trezise Jillian , Batterham Marijka , Okely Anthony D.
Published: August 2016

The aim of this study was to assess the feasibility, acceptability and potential efficacy of a physical activity program for preschool children. A 20-week, 2-arm parallel cluster randomized controlled pilot trial was conducted. The intervention comprised structured activities for children and professional development for staff. The control group participated in usual care activities, which included designated inside and outside playtime. Primary outcomes were movement skill development and objectively measured physical activity. At follow-up, compared with children in the control group, children in the intervention group showed greater improvements in movement skill proficiency, with this improvement statically significant for overall movement skill development (adjust diff. = 2.08, 95% CI 0.76, 3.40; Cohen’s d = 0.47) and significantly greater increases in objectively measured physical activity (counts per minute) during the preschool day (adjust diff. = 110.5, 95% CI 33.6, 187.3; Cohen’s d = 0.46). This study demonstrates that a physical activity program implemented by staff within a preschool setting is feasible, acceptable and potentially efficacious.
Validity of the Oxygen Uptake Efficiency Slope in Children With Cystic Fibrosis and Mild-To-Moderate Airflow Obstruction
Authors: Bongers Bart C. , Hulzebos Erik H.J. , Arets Bert G.M. , Takken Tim
Published: August 2016

Purpose: The oxygen uptake efficiency slope (OUES) has been proposed as an ‘effort-independent’ measure of cardiopulmonary exercise capacity, which could be used as an alternative measurement for peak oxygen uptake (VO2peak) in populations unable or unwilling to perform maximal exercise. The aim of the current study was to investigate the validity of the OUES in children with cystic fibrosis (CF). Methods: Exercise data of 22 children with CF and mild to moderate airflow obstruction were analyzed and compared with exercise data of 22 healthy children. The OUES was calculated using data up to three different relative exercise intensities, namely 50%, 75%, and 100% of the total exercise duration, and normalized for body surface area (BSA). Results: Only the OUES/BSA using the first 50% of the total exercise duration was significantly different between the groups. OUES/BSA values determined at different exercise intensities differed significantly within patients with CF and correlated only moderately with VO2peak and the ventilatory threshold. Conclusion: The OUES is not a valid submaximal measure of cardiopulmonary exercise capacity in children with mild to moderate CF, due to its limited distinguishing properties, its nonlinearity throughout progressive exercise, and its moderate correlation with VO2peak and the ventilatory threshold.
The Relationship Between Motor Proficiency and Pedometer-Determined Physical Activity in Young Children
Authors: Kambas Antonis , Michalopoulou Maria , Fatouros Ioannis G. , Christoforidis Christos , Manthou Eirini , Giannakidou Dimitra , Venetsanou Fotini , Haberer Elke , Chatzinikolaou Athanassios , Gourgoulis Vassilios , Zimmer Renate
Published: August 2016

The aim of this study was to examine the relationship between motor proficiency and pedometer-determined physical activity in 5–6 year-old children. Participants (n = 232) were randomly recruited and assessed from 30 kindergartens in Northern Greece. Two trained researchers administered the measurements for the assessment of children’s motor proficiency by using the BOTMP-SF. Physical activity was assessed by OMRON pedometers. Significant relationships between BOTMP-SF standard score and steps (S), aerobic walking time (AWT) and aerobic steps (AS), (p < .05) were found. When motor proficiency was divided into quartiles to assess the distribution of the relationship between motor proficiency and pedometer- derived variables, significant associations were found for AWT, S and AS (p < .001). Young children with high levels of motor proficiency were more active in contrast to their peers with lower motor proficiency. The findings add to the growing body of literature that considers motor skills/abilities as important elements of physical activity participation. (Abbreviations: S-steps per day; AS-aerobic steps per day; AWT-aerobic walking time (minutesfiay−1); BOTMP-SF-Bruininks-Oseretsky Test of Motor Proficiency-Short Form (standard score))
A Longitudinal Evaluation of Physical Activity in Brazilian Adolescents: Tracking, Change and Predictors
Authors: Dumith Samuel C. , Gigante Denise P. , Domingues Marlos R. , Hallal Pedro C. , Menezes Ana M.B. , Kohl Harold W.
Published: August 2016

This study aimed to: 1) describe the change in leisure-time physical activity (LTPA) during early-to-mid adolescence; 2) analyze the tracking of LTPA; 3) identify the predictors of LTPA change. 4,120 adolescents were from 11 to 15 years old. Outcome was self-reported LTPA (min/wk). Boys increased their LTPA level over the four years (mean: 75 min/wk; 95%CI: 49,100), whereas a decrease was observed among girls (mean: -42 min/wk; 95%CI: -57,-28). Likelihood to be active at 15 years of age was 50% higher (95%CI: 39–62) among those who were active at 11 years. The main predictor of LTPA change was the number of physical activities performed at baseline. Regular physical activity early in life can predict this behavior afterward.
Normative and Criterion-Related Standards for Shuttle Run Performance in Youth
Authors: Silva Gustavo , Aires Luísa , Mota Jorge , Oliveira José , Ribeiro José Carlos
Published: August 2016

The purpose of this study was to calculate and validate reference standards for the 20-m shuttle run test (SR) in youths aged 10–18 years. Reference standards based on the number of completed SR laps were calculated by LMS method in a reference group of 5559 students. Cut-off values for SR laps were determined and tested by ROC curve analysis in a validation group (633 students), from which waist circumference, HDL-cholesterol, triglycerides, fasting glucose and mean arterial pressure were assessed to calculate a metabolic risk score, later dichotomized in low and high metabolic risk (HMRS). The accuracy of SR laps standards was significant for girls (AUC = 0.66; 95% CI = 0.58–0.74; p < .001) and boys (AUC = 0.71; 95% CI = 0.62–0.79; p < .001) for identifying subjects at HMRS. The 40th percentile was the best cut-off for SR laps in girls (SENS = 0.569; 1-SPEC = 0.330) and boys (SENS = 0.634; 1-SPEC = 0.266). New SR laps reference standards are able to discriminate metabolic risk levels, and may provide a valuable tool for early prevention of cardiovascular risk factors.
Effects of Caffeine on Anaerobic Exercise in Boys
Authors: Turley Kenneth R. , Rivas Joey D. , Townsend Jeremey R. , Morton Aaron B. , Kosarek Jason W. , Cullum Mark G.
Published: August 2016

The effects of caffeine on anaerobic exercise in young boys was investigated. Twenty-four healthy 8–10 year old boys participated in a randomized doubleblind, double-crossover, counter-balanced study. Each subject received the caffeinated drink (CAF—5 mg · kg−1) or placebo (PL) twice each on four separate visits. Sixty minutes following ingestion of either CAF or PL boys performed a static hand-grip test and then a Wingate test. Reliability was moderately high for the Wingate test (R = .70–0.95). Hand-grip reliability was higher for CAF (R = .88) than PL (R = .52). Mean power (180 ± 36 vs 173 ± 28 W) was significantly higher (p < .05) in CAF versus PL, respectively. There were no differences in peak power or static hand-grip maximal voluntary contraction with CAF. Further, peak HR (190 ± 10 vs 185 ± 10 beats · min−1) was significantly higher in CAF versus PL, respectively. Thus, in this study a moderately high dose of CAF significantly increased the average power during a Wingate test, yet it does not affect peak power or static hand-grip strength.