Longitudinal associations among cardiorespiratory and muscular fitness,motor competence and objectively measured physical activity

ObjectivesThis study aimed to investigate cross-lagged associations in motor competence, cardiorespiratory fitness, muscular fitness and accelerometer-based moderate-to-vigorous physical activity (MVPA) engagement.DesignOne-year prospective follow-up study.MethodsA sample was 491 (275 girls; M at baseline = 11.27, SD = .32) Finnish physical education students. Students’ motor competence was assessed by (1) two-legged jumping from side to side test, (2) throwing-catching combination test and (3) 5-leaps test. Their cardiorespiratory fitness was analyzed by a 20-m shuttle run test and muscular fitness by curl-up and push-up tests. Additionally, students’ MVPA was measured objectively by hip-worn accelerometers.ResultsResults demonstrated that: (1) cardiorespiratory fitness measured at Grade 5 was the only significant predictor of later MVPA and this association appeared only in the boys’ group, (2) MVPA assessed at Grade 5 significantly predicted cardiorespiratory fitness in the girls’ group, (3) cardiorespiratory fitness collected at Grade 5 associated with muscular fitness, locomotor and stability skills in both girls and boys, and (4) locomotor skills measured at Grade 5 predicted significantly muscular fitness, locomotor and manipulative skills in both sex groups.ConclusionsElementary school years are important in providing students with experiences in physical activity (PA) which leads to improvements s in cardiorespiratory health. Additionally, this study showed that cardiorespiratory fitness collected at Grade 5 associated with later muscular fitness, and locomotor and stability skills in both sex groups. These findings are noteworthy because muscular fitness in youth has several health-related benefits and motor competence in childhood and adolescence has positive association with later PA engagement.     

‘Maths on the move’: Effectiveness of physically-active lessons for learning maths and increasing physical activity in primary school students

ObjectivesThis study evaluated the benefit of physically-active lessons for learning maths multiplication-tables. The impact of the intervention on general numeracy, physical activity (PA), aerobic fitness, body mass index (BMI) and school-day moderate to vigorous PA (MVPA) was also assessed.DesignRandomised controlled cross-over trial.MethodYear 3 students (n = 172, mean age 8.4 ± 0.3 years, 48% male) were recruited from 10 classes across two urban primary schools. Participants were randomly assigned to a seated classroom (Classroom) group or physically-active lessons in the playground (Playground) and crossed over to the alternative condition in the subsequent school term. The 6-week intervention comprised 3 × 30 min sessions/week. Multiplication-tables (teacher-designed test) and general maths (standardised test) were assessed pre- and post-intervention. Aerobic fitness was assessed via the shuttle-run. Pre- to post-intervention change scores were compared for analysis and effect sizes (ES) calculated. Total PA and MVPA were assessed with accelerometers in a subset of participants.ResultsMultiplication scores improved significantly more in Playground than Classroom groups (ES = 0.23; p = 0.045), while no significant differences were observed in general numeracy (ES = 0.05; p = 0.66). Total PA and MVPA were substantially higher during Playground than Classroom lessons (ES: total PA = 7.4, MVPA = 6.5; p < 0.001) but there were no differences in PA/MVPA between the groups throughout the rest of the school day. Aerobic fitness improved more in Playground than Classroom groups (ES = 0.3; p < 0.001) while the change in BMI was not different between groups (p = 0.39).ConclusionsPhysically-active lessons may benefit the learning of maths multiplication-tables while favourably contributing to school-day PA/MVPA.     

Relationship between meeting physical activity guidelines and motor competence among low-income school youth

ObjectivesGlobal health guidelines suggest that youth should accumulate at least 60 min of daily, moderate-to-vigorous-intensity physical activity (MVPA). The relationship between meeting physical activity (PA) guidelines and motor competence (MC) in youth is relatively unknown. This study assessed levels of MVPA and MC among socially vulnerable youth and determined if meeting the PA guidelines was associated with MC.DesignCross-sectional.MethodsA total of 1017 youths aged 3–14 years from three schools participated in the study. Participants wore accelerometers for seven consecutive days to assess PA. Motor competence was assessed using the Test of Gross Motor Development, 2nd Edition and the Körperkoordinationstest für Kinder. MVPA and MC were compared by sex and school levels (preschool, elementary school and middle school). Binary logistic regression models examined the predictive power of meeting PA guidelines and age on MC.ResultsThe prevalence of meeting PA guidelines declined across school levels among both girls (72% in preschool to 21% in middle school, p < 0.001) and boys (84% in preschool to 57% in middle school, p < 0.001). MC levels were low and also declined across age in both sexes (p < 0.001). During preschool, age (older) was a consistent predictor of low MC, independently of meeting PA guidelines.ConclusionsExcept for adolescent boys, meeting PA guidelines was not associated with higher MC. Public health policies should focus on the quantity and quality of MVPA within schools and on alleviating the decline in PA and MC across childhood and adolescence, with special attention to girls and disadvantaged families.     

Are children with higher self-reported wellbeing and perceived motor competence more physically active? A longitudinal study

ObjectivesSelf-perceptions such as perceived motor competence and psychosocial wellbeing have been identified as important to children’s physical activity. The study’s purpose was to explore whether perceived motor competence and psychosocial wellbeing were determinants of physical activity, one year after a baseline assessment.DesignLongitudinal study.MethodsA total of 134 children (65.7% boys, 34.3% girls) aged 6–7 years at baseline (2016), and 7–8 years at follow-up (2017) were included in this study. Pearson’s correlations assessed associations at baseline and follow-up between moderate- to vigorous-intensity physical activity (MVPA) (accelerometers) and (i) total perceived motor competence and subdomains (the pictorial scale of Perceived Movement Skill Competence) and (ii) psychosocial wellbeing and sub-domains — KidKINDL KINDer Lebensqualitätsfragebogen: Children Quality of Life Questionnaire (KINDL^R). Variables identified as significant in Pearson’s correlations were included in mixed model analyses, adjusting for accelerometer wear time, sex and age.ResultsBaseline perceived object control skills was associated with MVPA at follow-up (r = 0.38, p < 0.001), but perceived locomotor skills were not. Self-esteem was the only subdomain of psychosocial wellbeing that demonstrated significant association with MVPA at baseline (r = 0.21, p < 0.05). Perceived object control (B = 1.36, p = 0.019, 95% CI [0.23, 2.50]) and self-esteem (B = 0.32, p = 0.001, 95% CI [0.13, 0.50]) positively predicted MVPA; albeit with small effects.ConclusionsFocusing on improving children’s perceived object control and self-reported self-esteem may contribute to children’s physical activity participation.     

Can anthropometry and physical fitness testing explain physical activity levels in children and adolescents with obesity?

ObjectivesAs time with patients and resources are increasingly limited, it is important to determine if clinical tests can provide further insight into real-world behaviors linked to clinical outcomes. The purpose of this study was to determine which aspects of anthropometry and physical fitness testing are associated with physical activity (PA) levels among youth with obesity.DesignCross-sectional study.MethodAnthropometry [height, waist circumference, bodyweight, fat percentage], physical fitness [muscular endurance (partial curl-ups), flexibility (sit-and-reach), lower-body power (long-jump), upper-body strength (grip), speed/agility (5 × 5-m shuttle), cardiorespiratory fitness (VO₂-max)], and PA [light (LPA), moderate (MPA), vigorous (VPA), MVPA] was assessed in 203 youth with obesity.ResultsThe sample was stratified by age <12 yrs (children); 12 yrs (adolescents) and sex. Stepwise regression evaluated associations between PA with anthropometry and physical fitness. Children (57% male) and adolescents (45% male) had a BMI Z-score of 3.5(SD:0.94) and 3.1(SD:0.76) respectively. Long-jump explained 19.5% [(Standardized) Beta = 0.44; p = 0.001] of variance in VPA for childhood girls and 12.6% (Beta = 0.35; p = 0.025) of variance in MPA for adolescent boys. 5 × 5-m shuttle explained 8.4% (Beta = −0.29; p = 0.042) of variance in MVPA for childhood girls. Body mass explained 6.3% (Beta = −0.25; p = 0.007) of variance in LPA in childhood boys. Fat percentage explained 9.8% (Beta = 0.31; p = 0.03) of variance in MPA in adolescent girls.ConclusionsIn conclusion, tests of lower body power, body mass and fat percentage provide limited information concerning PA levels in youth with obesity. Activity monitoring should be considered in addition to clinical assessments to more fully understand youth health.     

Reallocating time spent in physical activity intensities: Longitudinal associations with physical fitness (DADOS study)

ObjectivesFirstly, to investigate the longitudinal associations between accelerometer-derived physical activity (PA) intensities and physical fitness (PF) at 24-month follow-up in adolescents. Secondly, to examine how substituting time spent in low or moderate PA intensities with vigorous PA at baseline was related to PF at 24-month follow-up.DesignLongitudinal observational studyMethodThe DADOS (Deporte, ADOlescencia y Salud) study is a 3-year longitudinal research project carried out between years 2015–2017. The analyses included 189 adolescents (91 girls) aged 13.9 ± 0.3 years at baseline. PA was assessed by a wrist-worn GENEActiv triaxial accelerometer and expressed as minutes/day of light, moderate and vigorous PA. Cardiorespiratory, musculoskeletal and motor fitness were assessed by field tests and a global fitness z-score was calculated as the mean of the z-scores values of each fitness test. Association between PA intensities and PF were determined using linear regression. Isotemporal analyses estimating the association of reallocating PA intensities with PF were performed.ResultsBaseline vigorous PA was positively associated with cardiorespiratory fitness and global fitness score at follow-up in boys (β = 0.234;p = 0.002, β = 0.340;p < 0.001) and girls (β = 0.184;p = 0.043, β = 0.213;p = 0.004). In boys, baseline vigorous PA was also positively associated with musculoskeletal and motor fitness (β = 0.139;p = 0.035, β = 0.195;p = 0.021). The substitution of 10 min/day of light PA or moderate PA with 10 min/day of vigorous PA at baseline was positively associated with all PF components and global fitness score in boys (p < 0.001), and with global fitness score girls (p < 0.05).ConclusionThese findings highlight the need of promoting vigorous PA due to its specific influence on adolescent's PF.     

Femoral torsion assessment with MRI in children: Should we use the bony or cartilaginous contours?

ObjectiveTo assess whether the use of cartilaginous contours at the femoral condyles instead of bony contours significantly changes femoral torsion measurements in children.Materials and MethodsFemoral torsion was measured in 32 girls (mean age 10.1 years ± 2.3 standard deviation) and 42 boys (10.9 years ± 2.5) on axial magnetic resonance (MR) images by two independent readers (R1,R2). The femoral condyle angle was measured using each the cartilaginous and bony contours of the distal femur. Cartilage thickness at femoral condyles was assessed. Intraclass-correlation-coefficient (ICC) and Pearson's correlation were used for statistical analysis.ResultsMean difference between cartilaginous and bony femoral torsion in girls was −1.1° ± 1.75 (range, −5.4° to 3.1°) for R1 and −1.64° ± 1.67 (−6.3° to 2.1°) for R2, in boys −1.5° ± 1.87 (−8.4° to 1.1°) for R1 and −2.28° ± 1.48 (−4.3° to 9.7°) for R2. Weak-to-moderate correlations between difference of cartilaginous-versus-bony measurements and cartilage thickness (r = −0.15 to −0.55, P < 0.001–0.46) or age (r = −0.33 to 0.46, P < 0.001–0.006) were found for both genders. Intermethod-ICC for cartilaginous versus bony femoral torsion measurements was 0.99/0.99 for R1/R2 in girls, and 0.99/0.98 in boys.ConclusionThere is only a small difference when measuring femoral torsion through cartilaginous versus bony contours, and no major difference in this between boys and girls.     

Comprehensive physical fitness and high blood pressure in children and adolescents: A national cross-sectional survey in China

ObjectivesTo assess the association between comprehensive physical fitness and high blood pressure (HBP) among Chinese children and adolescents.DesignNational cross-sectional surveys.Methods214,301 school students’ data aged 7−18 years was extracted in 2014. Six components of physical fitness (forced vital capacity, standing long jump, sit-and-reach, body muscle strength, 50 m dash and endurance running) were measured, standardized and aggregated as a summary physical fitness indicator (PFI). HBP, systolic HBP (SHBP) and diastolic HBP (DHBP) were defined according to sex-, age- and height-specific references in China.ResultsThe prevalence of HBP, SHBP and DHBP was 8.6%, 4.7% and 5.7%, respectively, and PFI was −0.9 in Chinese children and adolescents. A significant negative association between the PFI and HBP was observed with adjusted prevalence of HBP (10.8% (95% CI: 10.4–11.2) to 7.6% (95% CI: 7.3–8.0), P_trend < 0.001), SHBP (5.7% (95% CI: 5.4–6.1) to 4.4% (95% CI: 4.1–4.6), P_trend < 0.001), and DHBP (7.6% (95% CI: 7.2–7.9) to 4.6% (95% CI: 4.3–4.9), P_trend < 0.001) and their ORs (HBP: 0.87(95% CI: 0.82–0.93) to 0.68(95% CI: 0.64–0.73), P_trend < 0.001; SHBP: 0.86(95% CI: 0.79–0.94) to 0.75(95% CI:0.69–0.82), P_trend < 0.001; DHBP: 0.85(95% CI: 0.79–0.92) to 0.59(95% CI: 0.54–0.64), P_trend < 0.001) declined with the increase in PFI. Stratified nutritional status exhibited a similar negative association between PFI and HBP, SHBP and DHBP in children with normal weight, overnutrition, and undernutrition. Stand long jump, body muscle strength, 50 m dash, and endurance running, had a negative association with HBP, SHBP and DHBP, but forced vital capacity had a positive such association. Sit-and-reach and HBP are not significantly associated.ConclusionsPhysical fitness was negatively correlated to the increased HBP in children and adolescents. Comprehensive policies and measures to enhance children and adolescents’ physical fitness are urgently needed through the promotion of physical activity, healthy dietary patterns, and strategies of educational guidelines to reduce schoolwork, which will in turn reduce the cardiovascular burdens in the future.     

Are children’s perceptions of neighbourhood social environments associated with their walking and physical activity?

This study aimed to examine cross-sectional associations between neighbourhood social environmental factors and physical activity (PA) among Australian primary school children. Baseline data from a large-scale trial among 957 children (48% boys) aged 9–12 years were utilised. Children self-reported their perceptions of the neighbourhood social environment including social networks (e.g. there are lots of other children around to play with), and social capital (e.g. there are lots of people in my area I could go to if I need help). Children also self-reported their weekly walking frequency and PA from which average daily moderate to vigorous PA (MVPA) was calculated. Linear regression analyses examined these associations. Boys performed 17 min/day more MVPA than girls (p < 0.01), and girls performed one extra trip/week than boys (p < 0.001). Children’s perceptions of social capital (p < 0.0001) and social networks (p < 0.01) were both positively associated with MVPA and social capital was positively associated with walking frequency (p < 0.05). These associations were not moderated by the child’s sex. These findings suggest that children who had positive perceptions of neighbourhood social capital and social networks in the neighbourhood, tended to be more physically active. Longitudinal and experimental studies are required to further test the influence of these factors among children.     

Secular trends in health-related physical fitness in Spanish adolescents: The AVENA and HELENA Studies

We analysed the secular trends in health-related physical fitness in Spanish adolescents between 2001–2002 and 2006–2007. Two representative population studies were conducted 5 years apart in adolescents (12.5–17.5 years) from Zaragoza (Spain) that participated in the AVENA study in 2001–2002 and in the HELENA-CSS study in 2006–2007. Both studies used the same tests to assess physical fitness: the handgrip strength, bent arm hang, standing broad jump, 4 × 10 m shuttle run and 20 m shuttle run tests. Performance in 4 × 10 m shuttle run and 20 m shuttle run tests was higher in 2006–2007 (Cohen's d ranging from 0.2 to 0.4, p < 0.05), whereas performance in handgrip strength and standing broad jump tests was lower in 2006–2007 (Cohen's d ranging from 0.3 to 1.1, p < 0.001). Adjustment for age, pubertal status, fat mass, fat free mass and parental education did not alter the results. The odds ratio (OR) of meeting the FITNESSGRAM Standards for healthy cardiorespiratory fitness was higher in 2006–2007 in both boys (OR, 95% CI: 2.123, 1.157–3.908) and girls (OR, 95% CI: 2.420, 1.377–4.255). The results indicate that levels of both speed/agility and cardiorespiratory fitness were higher in 2006–2007 than in 2001–2002, whereas muscular strength components were lower in 2006–2007.     

The impact of a teacher-led structured physical activity session on preschoolers’ sedentary and physical activity levels

ObjectivesThe purpose of this observational study was to examine differences in preschoolers’ sedentary time and physical activity (PA) participation between preschool-attending weekdays with and without a teacher-led structured PA session.DesignA sample of 200 preschoolers (5.3 ± 0.4 y; 113 boys) from 26 preschools in Flanders, Belgium were included in data analysis.MethodsParticipants wore a GT1M ActiGraph accelerometer on one preschool-attending weekday with and on one preschool-attending weekday without the provision of a teacher-led structured PA session. Preschoolers’ sedentary time, light PA, and moderate-to-vigorous physical activity (MVPA) during the time in preschool (08:00–16:00 h) and after preschool (16:00–20:00 h) were estimated. To assess differences in the outcome measures between both days, multi-level linear regression models were conducted.ResultsDuring the time at preschool, lower sedentary levels (β = 13.0 min; SE = 1.6; p < 0.001) and higher light PA (β = 2.9 min; SE = 0.7 p < 0.001) and MVPA levels (β = 10.1 min; SE = 1.1; p < 0.001) were prevalent on days with a structured PA session compared to days without a structured PA session in both boys and girls. After preschool, no differences were found between both days in sedentary time (β = 0.7; SE = 1.4; p > 0.05), light PA (β = 0.3; SE = 0.5; p > 0.05), and MVPA (β = 0.3; SE = 0.9; p > 0.05).ConclusionsThe results demonstrate that no compensatory changes were found after preschool for the structured PA session during the preschool hours. Therefore, a teacher-led structured PA session integrated in the preschool curriculum is a promising mean to decrease sedentary time and to increase PA in preschool-aged boys and girls.     

Drivers of adolescent adiposity: Evidence from the Australian LOOK study

ObjectivesTo contribute to our understanding of the drivers of body composition during adolescence we sought to employ valid and reliable measures to investigate cross-sectional and longitudinal relationships between percentage body fat (%BF) and physical activity (PA), moderate and vigorous PA (MVPA), sedentary time (ST), total energy, sugar and fat intake.DesignLongitudinal cohort study.MethodsWe measured 556 (289 male) participants at age 12.4 (SD 0.4) years, and 269 (123 males) at 16.3 (SD 0.4) years, for %BF (dual energy X-ray absorptiometry); habitual PA, MVPA, ST (accelerometry); and dietary intake (‘multi-pass’ weekday and weekend 24-h recall). Accounting for likely under-reporting of energy intake (Goldberg cut-off), general linear mixed modelling was used to generate relationships with %BF.ResultsCross-sectional analyses indicated that 10 min more MVPA per day was associated with 0.6 lower %BF (95%CI 0.4–0.9, p < 0.001), and 10 min less ST/day with 0.07 lower %BF (95%CI 0.00–0.15, p < 0.001), independently of PA. In contrast, %BF was unrelated to total energy (p = 0.4), sugar intake (p = 0.2) or fat intake (p = 0.9). Longitudinal analysis showed that if PA was increased by 3% (10,000 counts/day) over the 4 years, then %BF was reduced by 0.08 (95%CI 0.05–0.12, p = 0.06).ConclusionsThe independent relationships of %BF with PA and ST, but absence of relationships with energy, sugar or fat intake, suggest that general community campaigns in a developed country directed at reducing adolescent obesity through modifications to energy intake and output would benefit from a more concerted focus on the latter.     

Wrist-specific accelerometry methods for estimating free-living physical activity

ObjectivesTo compare accelerometry-derived estimates of physical activity from 9 wrist-specific predictive models and a reference hip-specific method.DesignProspective cohort repeated measures study.Methods110 participants wore an accelerometer at wrist and hip locations for 1 week of free-living. Accelerometer data from three axes were used to calculate physical activity estimates using existing wrist-specific models (3 linear and 6 artificial neural network models) and a reference hip-specific method. Estimates of physical activity were compared to reference values at both epoch (≤60-s) and weekly levels.Results9044 h were analysed. Physical activity ranged from 7 to 96 min per day of moderate-to-vigorous physical activity (MVPA). Method of analysis influenced determination of sedentary behaviour (<1.5 METs), light physical activity (1.5 to <3 METs) and MVPA (>3 METs) (p < 0.001, respectively). All wrist-specific models produced total weekly MVPA values that were different to the reference method. At the epoch level, Hildebrand et al. (2014) produced the strongest correlation (r = 0.69, 95%CI: 0.67–0.71) with tightest ratio limits of agreement (95%CI: 0.53–1.30) for MVPA, and highest agreement to predict MVPA (94.1%, 95%CI: 94.0–94.1%) with sensitivity of 63.1% (95%CI: 62.6–63.7%) and specificity of 96.0% (95%CI: 95.9–96.0%).ConclusionsCaution is required when comparing results from studies that use inconsistent analysis methods. Although a wrist-specific linear model produced results that were most similar to the hip-specific reference method when estimating total weekly MVPA, modest absolute and relative agreement at the epoch level suggest that additional analysis methods are required to improve estimates of physical activity derived from wrist-worn accelerometers.     

Prognostic value of pretreatment volume-based quantitative 18F-FDG PET/CT parameters in patients with malignant pleural mesothelioma

PurposeTo investigate the relationships between pretreatment volume-based quantitative ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) parameters and overall survival (OS) in patients with malignant pleural mesothelioma (MPM).Materials and methodsWe retrospectively reviewed data from 201 MPM patients, of whom 38 underwent surgical resection, and calculated the maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG), including primary tumors and nodal or distant metastatic lesions, on pretreatment ¹⁸F-FDG PET/CT. Relationships between clinicopathological factors (age, sex, performance status, European Organization for Research and Treatment of Cancer [EORTC] score, histological subtype, TNM stage, and treatment strategy), volume-based quantitative PET/CT parameters, and OS were evaluated using a Cox proportional hazards model and log-rank test.ResultsThe median follow-up was 15 months (range, 1–96 months; median, 17 months). In a univariate analysis of all patients, older age (p < 0.05), high EORTC score (p < 0.001), non-epithelioid histological subtype (p < 0.001), high T stage (p < 0.001), positive N/M status (p < 0.05, p < 0.001), advanced TNM stage (p < 0.001), non-surgical treatment (p < 0.001), and high SUVmax (p < 0.001), MTV (p < 0.001), or TLG (p < 0.001) were associated with significantly shorter OS. A multivariate analysis confirmed non-epithelioid subtype (hazard ratio [HR]: 1.69, 95% confidence interval [CI]: 1.14–2.48; p < 0.05), non-surgical treatment (HR: 0.58, 95% CI: 0.34–0.95; p < 0.05), and high TLG (HR: 1.97, 95% CI: 1.14–3.44; p < 0.05) as independent negative predictors.ConclusionsPretreatment volume-based quantitative ¹⁸F-FDG PET/CT parameters, especially TLG, could serve as potential surrogate markers for MPM prognosis.     

Sex and occupation are salient factors associated with lateral ankle sprain risk in military tactical athletes

ObjectivesTo assess the risk of lateral ankle sprain (LAS) in male and female tactical athletes across different military occupations in the US military.DesignRetrospective cohort.MethodsThe Defense Medical Epidemiology Database was queried for the number of individuals with ICD-9 diagnosis codes 845.00 (sprain of ankle, unspecified) and 845.02 (calcaneofibular ligament sprain) on their initial encounter from 2006 to 2015. Relative risk (RR) and chi-square statistics were calculated assessing sex and occupational category on LAS risk.Results272,970 enlisted males (27.9 per 1000 person-years), 56,732 enlisted females (34.5 per 1000 person-years), 24,534 male officers (12.6 per 1000 person-years), and 6020 female officers (16.4 per 1000 person-years) incurred a LAS. Enlisted females in all occupational groups were at significantly higher risk for LAS than their male counterparts (RR 1.09–1.68; p < 0.001), except for Engineers (p = 0.15). Female officers had consistently higher risk for LAS in all occupational groups (RR 1.10–1.42; p < 0.001) compared with male officers, except Ground/Naval Gunfire (p = 0.23). Contrasted with Infantry, enlisted tactical athletes in the Special Operations Forces, Mechanized/Armor, Aviation, Maintenance, and Maritime/Naval Specialties were at lower risk (RR 0.38?0.93; p < 0.001), Artillery, Engineers, and Logistics Specialties were at higher risk (RR 1.04–1.18; p < 0.001), and Administration, Intelligence, and Communications were no different (p = 0.69). Compared with Ground/Naval Gunfire officers, Aviation officers were at significantly lower risk (RR, 0.75; p < 0.001), and Engineers, Maintenance, Administration, Operations/Intelligence, and Logistics officers were at higher risk (RR, 1.08–1.20; p < 0.001).ConclusionsSex and military occupation were salient factors associated with LAS risk.     

Development of a new computer-based physical activity questionnaire to estimate habitual physical activity level in Malaysian adolescents

ObjectivesTo assess the validity and reproducibility of a new computer-based physical activity questionnaire (cPAQ) to estimate the habitual physical activity levels in Malaysian adolescents.DesignCross-sectional study.MethodsAbout 425 adolescent boys and girls participated in the study. A heart rate monitor and a 7-days physical activity logbook were used as objective and subjective method criteria, respectively.ResultsThe mean estimated weekly total physical activity levels measured by the cPAQ were 16.5 ± 17.5 h and 13.1 ± 16.9 h for boys and girls, respectively. Analyses of the gender-specific Spearman's correlation coefficient between cPAQ and both objective and subjective method criteria showed that r values ranged from 0.54 to 0.76 (p < 0.001). Method comparisons assessed by the Bland–Altman plot analysis found that the total physical activity levels, calculated from the cPAQ, fell within the mean ± 2 standard deviation. Reproducibility of the cPAQ was re-examined after two-weeks, showing that intra-class correlations for most PA intensity levels in boys and girls were high with a mean r value of 0.72. The effectiveness of the cPAQ showed a significantly shorter assessment time compared to the manual paper-administered questionnaire in adolescents (p < 0.001) and the majority of participants (93%) accepted the overall appearance of this new cPAQ.ConclusionsThe cPAQ provides a valid and reliable method for assessing the habitual physical activity levels for the past year in Malaysian adolescents. It was also proven to be highly effective, based on duration time and its overall appearance for the adolescent participants.     

Heart rate and blood lactate responses during Taekwondo training and competition

ObjectiveThe study investigated physical fitness characteristics of elite Taekwondo (TKD) players as well as their heart rate (HR) response and blood lactate concentration changes during TKD specific exercises and simulated competition.MethodsAnaerobic and aerobic power has been evaluated in eight elite TKD players (age: 20 ± 1 years, body mass: 70.8 ± 6 kg, Ht: 179.9 ± 4 cm). We also measured heart rate and blood lactate concentration during competition and specific-exercises (front kicks during 10 s, 1 and 3 min).ResultsMaximum oxygen uptake (VO₂max) and peak anaerobic power (Wpeak) averaged 56.22 ± 2.57 ml min^–1 kg^–1 and 12.1 ± 1.7 W kg^–1, respectively. HR and blood lactate [La] concentrations increased significantly during competition (F = 19.4, P < 0.001; F = 21.3, P < 0.001) compared to the resting value. HR and [La] values were significantly correlated with those measured during 10 s (R = 0.85, P < 0.05 and R = 0.79, P < 0.05, respectively) and 3-min specific exercises (R = 0.95, P < 0.01 and R = 0.76, P < 0.05).ConclusionsTKD requires high levels of both aerobic and anaerobic physical fitness. The correlation between specific exercises and competition is of practical interest for TKD players and trainers.     

Potential moderators and mediators of intervention effects in an obesity prevention program for adolescent boys from disadvantaged schools

ObjectivesThe purpose of this study was to explore potential moderators and mediators of intervention effects in the Physical Activity Leaders (PALs) obesity prevention program for adolescent boys from disadvantaged secondary schools.DesignGroup randomized controlled trial.MethodsOne hundred adolescent boys (mean age = 14.3 (0.6) years) from four schools were randomized to the PALs intervention or a control group for the 6-month study period. The primary outcome was change in BMI and secondary outcomes were physical activity assessed using pedometers and constructs from Social Cognitive Theory (SCT) assessed using a questionnaire.ResultsModeration analyses revealed a significant weight status interaction for BMI (p = 0.04), indicating stronger intervention effects for youth classified as overweight/obese at baseline. The intervention had a significant effect on resistance training self-efficacy (p < 0.001), but none of the SCT constructs satisfied the criteria for mediation. The number of intervention sessions attended was associated with changes in BMI (r = ?0.38, p = 0.001), resistance training self-efficacy (r = 0.42, p < 0.001) and physical activity behavioral strategies (r = 0.26, p = 0.018). Changes in BMI were also associated with changes in resistance training self-efficacy (r = ?0.21, p = 0.06) and physical activity behavioral strategies (r = ?0.29, p = 0.009).ConclusionsA school-based intervention incorporating student leadership increased adolescent boys’ resistance training self-efficacy, but changes in physical activity were not detected and none of the SCT constructs satisfied the criteria for mediation. Baseline weight status was a moderator of intervention effect with the strongest intervention effects observed among overweight and obese adolescent boys.     

Variability of gait,bilateral coordination,and asymmetry in women with fibromyalgia

PurposeTo analyze how fibromyalgia affected the variability, asymmetry, and bilateral coordination of gait walking at comfortable and fast speeds.Methods65 fibromyalgia (FM) patients and 50 healthy women were analyzed. Gait analysis was performed using an instrumented walkway (GAITRite system). Average walking speed, coefficient of variation (CV) of stride length, swing time, and step width data were obtained and bilateral coordination and gait asymmetry were analyzed.ResultsFM patients presented significantly lower speeds than the healthy group. FM patients obtained significantly higher values of CV_StrideLength (p = 0.04; p < 0.001), CV_SwingTime (p < 0.001; p < 0.001), CV_StepWidth (p = 0.004; p < 0.001), phase coordination index (p = 0.01; p = 0.03), and p_CV (p < 0.001; p = 0.001) than the control group, walking at comfortable or fast speeds. Gait asymmetry only showed significant differences in the fast condition.ConclusionFM patients walked more slowly and presented a greater variability of gait and worse bilateral coordination than healthy subjects. Gait asymmetry only showed differences in the fast condition. The variability and the bilateral coordination were particularly affected by FM in women. Therefore, variability and bilateral coordination of gait could be analyzed to complement the gait evaluation of FM patients.