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Background: This study assessed the specific influence of physical activity (PA) and waist circumference (WC) on the 4-year growth trajectory of blood pressure in UK high-school students., Methods: Four-year longitudinal monitoring of 1501 adolescents was conducted as part of the EoEHHS. Measurements were taken in Grades (G)7, 9, and 11., Results: Systolic (SBP) and diastolic blood pressure (DBP) increased over the 4-year period (SBP G7 114.6 ± 8.9 mmHg, G9 118.1 ± 9.7 mmHg, G11 122.8 ± 7.8 mmHg; DBP G7 66.7 ± 6.6 mmHg, G9 68.0 ± 6.4 mmHg, G11 70.0 ± 5.2 mmHg). Baseline WC predicted baseline and growth in SBP, but the strongest contribution to SBP came from changes in WC (β = 0.084, p = 0.002). Baseline PAQ-A score (β = -0.822, p = 0.020) and changes in PAQ-A score (β = -0.650, p = 0.019) were associated with smaller increases in DBP over the 4-year measurement period., Conclusions: Baseline and change in WC predicted the growth trajectory of SBP, while baseline and change in PA predicted the growth trajectory of DBP. PA and WC have a prognostic value in predicting changes in blood pressure in adolescents. Increasing PA during adolescence could slow the rise in DBP over time. This is meaningful for future hypertension and CVD risk reduction into adulthood., Impact: Hypertension in adolescents is a growing health problem that is often overlooked. Baseline and changes in waist circumference over a 4-year period predicted development of systolic blood pressure, while baseline and changes in physical activity predicted development of diastolic blood pressure. Physical activity and waist circumference have a prognostic value in predicting changes in blood pressure in adolescents and could be valuable in planning programmes to prevent hypertension in similar communities and reduce the risk of future adult hypertension., (© 2023. The Author(s).)

Non-communicable diseases (NCDs) are the leading cause of death globally, particularly impacting low- and middle-income countries and rural dwellers. Therefore, this programme aimed to investigate if a community-based mind-body PA programme implemented in a low-resource setting could improve health-related physical fitness outcomes. Black overweight or obese adult women (25 ± 4.7 years) with a body mass index (BMI) > 25 kg·m -2 recruited from a rural settlement in South Africa with manifest risk factors for multimorbidity were assigned to a 10-week waiting-to-treat non-exercising control group ( n = 65) or a community-based mind-body programme ( n = 60) consisting of 45-60 min, thrice-weekly Tae-Bo. The intervention resulted in significant ( p ≤ 0.05) improvements in body weight ( p = 0.043), BMI ( p = 0.037), and waist ( p = 0.031) and hip circumferences ( p = 0.040). Flexibility was found to be significantly increased at mid- and post-programme ( p = 0.033 and p = 0.025, respectively) as was static balance (mid: p = 0.022; post: p = 0.019), hand grip strength (mid: p = 0.034; post: p = 0.029), sit-up performance (mid: p = 0.021; post: p = 0.018), and cardiorespiratory endurance (mid: p = 0.017; post: p = 0.011). No significant change was found in sum of skinfolds following the programme ( p = 0.057). Such a community-based mind-body programme presents an opportunity to level health inequalities and positively improve health-related physical fitness in low-resource communities irrespective of the underlying barriers to participation.

Purpose: To assess the efficacy of a supervised in-school combined resistance and aerobic training program in adolescent girls and investigate whether responses differ according to birthweight., Methods: Participants (girls aged 13-17 y) were randomized either to an intervention replacing physical education (PE) classes with 2 × 60-minute training sessions per week (n = 58) or to a control group that continued to attend 2 × 60 minutes per week of curriculum PE (n = 41). We measured muscular fitness (handgrip, standing long jump, and sit-ups), cardiorespiratory fitness (20-m shuttle run), skinfolds, and lean body mass preintervention and postintervention and determined effect size (Hedge's g) differences between changes in these measures. We also compared changes within lower (<3000 g) and normal birthweight intervention and PE control subgroups., Results: The intervention group showed greater improvements in all the fitness measures and lean body mass (g = 0.22-0.48) and lower skinfold increases (g = 0.41) than PE controls. Within the intervention group, improvements in all fitness measures were larger in lower birthweight (g = 0.53-0.94) than in normal birthweight girls (g = 0.02-0.39)., Conclusion: Replacing curriculum PE with supervised training improved muscular and cardiorespiratory fitness and body composition outcomes in adolescent females. Our findings suggest an enhanced adaptive response to training in participants with lower birthweight which warrants further investigation.

The aim of this study was to evaluate the impact on muscle strength, aerobic fitness and body composition, of replacing the physical education (PE) class of Colombian adolescents with resistance or aerobic training. 120 tanner stage 3 adolescents attending a state school were randomized to resistance training, aerobic training, or a control group who continued to attend a weekly 2- hour PE class for 16 weeks. The resistance training and aerobic training groups participated in twice weekly supervised after-school exercise sessions of < 1 hour instead of their PE class. Sum of skinfolds, lean body mass (bioelectrical impedance analysis), muscular strength (6 repetition maximum (RM)) bench press, lateral pulldown and leg press) and estimated cardiorespiratory fitness (multistage 20 meter shuttle run) were assessed at pre and post intervention. Complete data were available for n = 40 of the resistance training group, n = 40 of the aerobic training group and n = 30 PE (controls). Resistance training attenuated increases in sum of skinfolds compared with controls (d = 0.27, [0.09-0.36]). We found no significant effect on lean body mass. Resistance training produced a positive effect on muscle strength compared with both controls (d = 0.66 [.49-.86]) and aerobic training (d = 0.55[0.28-0.67]). There was a positive effect of resistance training on cardiorespiratory fitness compared with controls (d = 0.04 [-0.10-0.12]) but not compared with aerobic training (d = 0.24 [0.10-0.36]). Replacing a 2-hour PE class with two 1 hour resistance training sessions attenuated gains in subcutaneous adiposity, and enhanced muscle strength and aerobic fitness development in Colombian youth, based on a median attendance of approximately 1 session a week. Further research to assess whether adequate stimuli for the development of muscular fitness exists within current physical education provision is warranted., Competing Interests: The authors have declared that no competing interests exist.

Growth and maturation affect long term physical performance, making the appraisal of athletic ability difficult. We sought to longitudinally track youth soccer players to assess the developmental trajectory of athletic performance over a 6-year period in an English Premier League academy. Age-specific z-scores were calculated for sprint and jump performance from a sample of male youth soccer players (n = 140). A case study approach was used to analyse the longitudinal curves of the six players with the longest tenure. The trajectories of the sprint times of players 1 and 3 were characterised by a marked difference in respective performance levels up until peak height velocity (PHV) when player 1 achieved a substantial increase in sprint speed and player 3 experienced a large decrease. Player 5 was consistently a better performer than player 2 until PHV when the sprint and jump performance of the former markedly decreased and he was overtaken by the latter. Fluctuations in players' physical performance can occur quickly and in drastic fashion. Coaches must be aware that suppressed, or inflated, performance could be temporary and selection and deselection decisions should not be made based on information gathered over a short time period.

Our aim was to examine whether a new ratio, waist divided by height 0.5 (WHT.5R), is both independent of stature and a stronger predictor of cardiometabolic risk (CMR) than other anthropometric indices. Subjects (4117 men and 646 women), aged 20-69 years, were assessed for stature (cm), mass (kg), waist, and hip girths (cm) from which body mass index (BMI), waist-to-hip ratio (WHR), waist-to-height ratio (WHTR), and two new indices, a body shape index (ABSI) and WHT.5R, were determined. We used the allometric power law, W = a.HT b , to obtain a simple body shape index for waist girth (W) to be independent of stature (HT). Physical activity was determined using self-report, and physical fitness was determined using the Bruce protocol. Glucose, total cholesterol, low-density lipoprotein, high-density lipoprotein, triglycerides, and TC/HDL ratio were determined from fasting venous blood samples. A single CMR composite score was derived from log-transformed z-scores of Triglycerides + average blood pressure ((diastolic + systolic)/2) + glucose + HDL (*-1). Results confirmed WHT.5R to be independent of stature and the strongest predictor of CMR, compared with BMI, WC, WHR, ABSI, and WHTR. We also found that CMR scores decline significantly with increasing fitness and physical activity, confirming that being fit and active can compensate for the adverse effects of being fat as measured by all other anthropometric indices. In conclusion, WHT.5R was the best anthropometric index associated with CMR, and being both physically fit and active has a protective effect on CMR, irrespective of weight status., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

This meta-analysis investigated the maturation-related pattern of adaptations to resistance training in boy athletes. We included studies examining the effects of 4-16-week resistance training programmes in healthy boy athletes aged 10-18 years. Pooled estimates of effect size for change in strength across all studies (n = 19) were calculated using the inverse-variance random effects model for meta-analyses. Estimates were also calculated for groups based on likely biological maturity status ("before", "during" and "after" peak height velocity). Using the standardised mean difference, resistance training increased strength across all groups (effect size = 0.98, [CI: 0.70-1.27]). Strength gains were larger during (1.11 [0.67-1.54]) and after (1.01 [0.56-1.46]) peak height velocity than before (0.5 [-0.06-1.07]). Adaptations to resistance training are greater in adolescent boys during or after peak height velocity. These findings should help coaches to optimise the timing of training programmes that are designed to improve strength in boy athletes.

Objectives: Compression garments are used by athletes in attempts to enhance performance and recovery, although evidence to support their use is equivocal. Reducing the exertion experienced during exercise may encourage sedentary individuals to increase physical activity. The aim of this study was to assess the effect of compression garments on walking performance (self-paced and enforced pace) and rate of perceived exertion (RPE) in adults who presented with two or more CVD risk factors. Participants (n=15, 10 female, 58.9±11.5 years, BMI 27.5±4.5kgm 2 ) were recruited., Design: A repeated measures design., Methods: Participants were randomised to Modified Bruce Protocol (enforced pace), or the 6min walk test (self-paced), and completed the test wearing compression garments or normal exercise clothes (Control). Outcome measures included stage completed, gross efficiency (%) and RPE in Modified Bruce Protocol, and distance walked (m) and RPE in 6 min walk test., Results: In the Modified Bruce Protcol participants had a higher RPE (15.5±2.5 vs 14.3±2.2) and a lower efficiency (19.1±5.9 vs 21.1±6.7) in the compression garment condition compared with control, p<0.05. In the 6 min walk test participants walked 9% less in the compression garment condition (p<0.05) but did not have a lower RPE., Conclusions: Compared with previous studies reporting enhanced or no effects of compression garments on performance or RPE, this study shows adverse effects of such clothing in untrained individuals with CVD risk factors. The mechanisms underlying this negative effect require further exploration. Use of garments designed for the athletic individuals may not be suitable for the wider population., (Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.)

Background: Age and body mass index (BMI) are positively associated with the development of the metabolic syndrome (MetS). Cardiorespiratory fitness (CRF) can attenuate BMI-related increases in prevalence of MetS, but the nature of this association across different age strata has not been fully investigated., Aim: To identify the association between CRF and MetS prevalence across age strata (20-69 years) and determine whether associations are independent of BMI., Methods: CRF was estimated from incremental treadmill exercise in British men attending preventative health screening. Participants were placed in four age strata (20-39, 40-49, 50-59 and 60-69 years) and classified as fit or unfit using age-related cut-offs. The presence of MetS was defined using the National Cholesterol Education Program Adult Treatment Panel III criteria., Results: 9666 asymptomatic men (48.7±8.4 years) were enrolled. The prevalence of MetS was 25.5% in all men and ranged from 17.1% in those aged 20-39 years to 30.6% in those aged 60-69 years. Fit men's likelihood of meeting the criteria for MetS was half (OR=0.51, 95% CI 0.46 to 0.57) that of unfit men. The likelihood of MetS was 32-53% lower across age strata in fit, compared with unfit men. Adjustment for BMI attenuated the association, though it remained significant in men aged 20-49 years., Conclusions: The cardiometabolic benefits of CRF are independent of BMI particularly in men <50 years. Public health messages should emphasise the important role of CRF alongside weight management for enhancing cardiometabolic health., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

Moran, J, Sandercock, GRH, Ramírez-Campillo, R, Meylan, CMP, Collison, J, and Parry, DA. Age-related variation in male youth athletes' countermovement jump after plyometric training: A meta-analysis of controlled trials. J Strength Cond Res 31(2): 552-565, 2017-Recent debate on the trainability of youths has focused on the existence of periods of accelerated adaptation to training. Accordingly, the purpose of this meta-analysis was to identify the age- and maturation-related pattern of adaptive responses to plyometric training in youth athletes. Thirty effect sizes were calculated from the data of 21 sources with studies qualifying based on the following criteria: (a) healthy male athletes who were engaged in organized sport; (b) groups of participants with a mean age between 10 and 18 years; and (c) plyometric-training intervention duration between 4 and 16 weeks. Standardized mean differences showed plyometric training to be moderately effective in increasing countermovement jump (CMJ) height (Effect size = 0.73 95% confidence interval: 0.47-0.99) across PRE-, MID-, and POST-peak height velocity groups. Adaptive responses were of greater magnitude between the mean ages of 10 and 12.99 years (PRE) (ES = 0.91 95% confidence interval: 0.47-1.36) and 16 and 18 years (POST) (ES = 1.02 [0.52-1.53]). The magnitude of adaptation to plyometric training between the mean ages of 13 and 15.99 years (MID) was lower (ES = 0.47 [0.16-0.77]), despite greater training exposure. Power performance as measured by CMJ may be mediated by biological maturation. Coaches could manipulate training volume and modality during periods of lowered response to maximize performance.

The incremental shuttle walk test (ISWT) is used to assess functional capacity of patients entering cardiac rehabilitation. Factors such as age and sex account for a proportion of the variance in test performance in healthy individuals but there are no reference values for patients with cardiovascular disease. The aim of this study was to produce reference values for the ISWT. Participants were n = 548 patients referred to outpatient cardiac rehabilitation who underwent a clinical examination and performed the ISWT. We used regression to identify predictors of performance and produced centile values using the generalised additive model for location, scale and shape model. Men walked significantly further than women (395 ± 165 vs. 269 ± 118 m; t = 9.5, P < 0.001) so data were analysed separately by sex. Age (years) was the strongest predictor of performance in men (β = -5.9; 95% CI: -7.1 to -4.6 m) and women (β = -4.8; 95% CI: -6.3 to 3.3). Centile curves demonstrated a broadly linear decrease in expected ISWT values in males (25-85 years) and a more curvilinear trend in females. Patients entering cardiac rehabilitation present with highly heterogeneous ISWT values. Much of the variance in performance can be explained by patients' age and sex. Comparing absolute values with age-and sex-specific reference values may aid interpretation of ISWT performance during initial patient assessment at entry to cardiac rehabilitation.

Objectives: To compare cardiovascular fitness and physical activity of schoolchildren 18 months after London 2012 according to Olympic 'inspiration'., Design: A cross-sectional comparison between groups of schoolchildren categorised according to self-reported Olympic inspiration and a repeated cross-sectional comparison using data collected pre-2012., Setting: Schools within a 50 km radius of the Olympic Park, Stratford, London., Participants: 931 students (10.0-15.9-year-olds) attending 6 schools assessed in 2013 and 2014 (18 (range: 14-20) months after London 2012) and 733 students from the same schools assessed in 2008-2009 (42 (range: 38-46) months before London 2012)., Primary Outcome Measures: Self-reported Olympic inspiration; cardiorespiratory fitness ([Formula: see text] mL/kg/min) assessed using the 20 m shuttle-run and self-reported physical activity., Secondary Outcomes Measures: Differences in [Formula: see text] before and after London 2012., Results: 53% of children reported being inspired to try new sports or activities. Compared with those not inspired by the Games, [Formula: see text] was higher in boys (d=0.43) and girls (d=0.27), who continued to participate in activities at 18(14-20) months. This 45% of sample was also more physically active (boys, d=0.23; girls, d=0.38) than those not or only briefly inspired to participate in activities (boys, d=0.24; girls, d=0.21). Compared with pre-2012 values, [Formula: see text] was lower post-2012 in boys (d=0.37) and in girls (d=0.38)., Conclusions: High levels of inspiration to participate in new activities reported following London 2012 and positive associations with fitness are encouraging. We cannot discount the possibility that inspired participants may have already been fitter and more active pre-2012. These associations must be interpreted in the context of the significant declines in fitness shown by our repeated cross-sectional comparison. Olympic host countries should employ longitudinal monitoring using objectively measured fitness and physical activity to provide evidence of health-related legacy., Competing Interests: Conflicts of Interest: None declared., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.)

The aim of the study was to compare and contrast habitual physical activity (PA) profiles and muscular fitness in schoolchildren from northern and southern regions of England. Data were collected from two secondary schools in the north east (NE) of England. The study procedures followed methods employed by the East of England Healthy Hearts Study in 10-16-year-old boys and girls based in the south east (SE) region of England and data were compared. Habitual physical activity (PAQ-A), vertical jump test, and hand-grip (HG) strength were assessed. We converted raw scores from all assessments to age- and sex-normalised z-scores. We recruited 597 children (58% boys) in the NE and compared findings to 597 age- and sex-matched boys and girls from the SE. Boys in the SE had significantly stronger HG scores, jumped higher, were more powerful (mean peak power: 2131 W vs. 1782 W; P < 0.0001), and reported being more physically active (mean PAQ-A: 2.9 vs. 2.5; P < 0.0001) than their male counterparts in the NE. In girls, the opposite trend was evident. Girls from the NE of England had a higher HG score, jumped higher, and were more powerful (mean peak power: 2114 W vs. 1839 W; P < .0001) than their peers from the SE. Regional variations in the habitual PA profiles and muscular fitness of schoolchildren from the SE and NE of England do exist. The systematic surveillance of children's PA and fitness profiles throughout England would help identify regional inequalities on a larger scale.

Background: Exercise-based cardiac rehabilitation can promote meaningful improvements in cardiorespiratory fitness (fitness) but the magnitude of such improvements varies according to local characteristics of exercise programmes. We aimed to determine if cardiac rehabilitation (CR), as practised in the United Kingdom (UK), could promote meaningful changes in fitness and to identify programme characteristics which may moderate these changes., Methods: Electronic and manual searches to identify UK CR studies reporting fitness at baseline and follow up. Change in fitness (Δfitness) was expressed as mean difference (95% CI) and effect size (ES). A random effects model was used to calculate the mean estimate for change in Δfitness. Between-group heterogeneity was quantified (Q) and investigated using planned sub-group analyses., Results: We identified n=11 studies containing 16 patient groups (n=1 578) which used the incremental shuttle walking test (ISWT) (distance walked) to assess fitness. The overall mean estimate for Δfitness showed a significant increase in distance walked (ES=0.48, P<0.001), but this estimate was highly heterogeneous (Q=77.1, P<0.001, I(2)=81%). Sub-group analyses showed significantly greater ES (Q=3.94, P=0.046) for Δfitness in patients prescribed n>12 exercise sessions compared with those receiving n≤12 sessions., Conclusion: We found significant increases in fitness (based on ISWT) in patients attending exercise-based CR in the UK. However, UK studies provide approximately one-third of the exercise "dose", and produce gains in fitness less than half the magnitude reported in international studies., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

The aim of this study was to determine whether ownership and use of electronic media were associated with sedentary time and cardiorespiratory fitness (fitness) in youth. We also aimed to determine if associations were independent of physical activity (PA). Fitness was measured using the 20 m shuttle-run. PA, sedentary time, ownership of media devices and media use were self-reported. Participants (n = 678, age 10-15 years) reported daily sedentary time of 620 (± 210) min. Forty-one percent of participants had low PA and 50.4% had low fitness. Higher weekend sedentary time was associated with low fitness in girls (p = 0.005) and boys (p < 0.001) and remained significant when adjusted for PA in the latter (p = 0.006). Using social media was associated with higher sedentary time in both sexes and low fitness in girls. High sedentary time was more likely (OR = 5.3, 95%CI: 2.0-14.4) in boys who owned game consoles. Low fitness was more likely in boys who owned digital/satellite TV receivers (OR = 1.8, 95%CI: 1.8-3.2). Schoolchildren spent > 10 h or ~ 85% of each waking day sedentary. Use of social media was associated with higher sedentary time in both sexes and with low fitness in girls. Reducing social media use in youth offers one potential target for intervention. Behaviours associated with sedentary time differed from predictors of low fitness. The complex and often sex-specific interactions identified between sedentary time, PA and fitness suggest the need for carefully targeted interventions to reduce sedentary time and improve fitness in English youth.

We aimed to describe the frequency of showering after physical education (PE) in English high-school pupils. We examined differences in physical activity (PA) and cardiorespiratory fitness according to showering behaviours and examined predictors of showering. We measured PA and cardiorespiratory fitness of n = 3921 pupils (11-16 years, 53.5% males) from eight high schools. Pupils self-reported showering behaviour and parental PA levels. We calculated deprivation and distance travelled to school from their home postcode. Overall, 53% of boys and 68% of girls said they never shower after PE. Pupils who did not shower after PE were less physically active and engaged in fewer team sports. Girls who did not shower also had lower cardiorespiratory fitness than those who did. Showering behaviour varied greatly by school, so we adjusted for clustering at the school level. Pupils were more likely to shower if they were active with their parents [odds ratio (OR) = 1.72; 95% CI: 1.43, 2.07] and less likely to shower if they were from deprived areas (OR = 0.68; 95% CI: 0.52, 0.88). Showering after PE is relatively rare in English schoolchildren, particularly girls. While we cannot infer causality regarding the relationships found here, the low rates of showering and the lower PA and cardiorespiratory fitness (in girls) observed in schoolchildren who do not shower suggest research is needed to determine whether showering is a barrier to being physically active during PE.

We compared values of body mass index (BMI) and cardiorespiratory fitness (20 m shuttle-run test) of n=157 boys and n=150 girls aged 10-11 measured in 2014 with measures from 2008 and 1998. Boys' fitness was lower (d=0.68) in 2014 than 2008, despite a small (d=0.37) decline in BMI. Girl's BMI changed trivially (d=0.08) but cardiorespiratory fitness was lower (d=0.47) in 2014 than 2008. This study suggests fitness is declining at 0.95% per year, which exceeds the 0.8% rate of decline we reported between 1998 and 2008 and is double the global average of 0.43%. Declines in fitness were independent of changes in BMI suggesting continued reductions in English children's habitual physical activity levels.

Background: Sleep duration is an important predictor of obesity and health. This study evaluated the association between late bedtime and screen time, and the role of geographical deprivation in English schoolchildren., Methods: We collected bedtime and waking time, screen time, sociodemographic data and measured body mass index in a cross-section of 1332 11-15-year-old schoolchildren (45.7% female) participating in the East of England healthy heart study. Logistic regression was used to determine the likelihood of late bedtime in schoolchildren with different screen time and from a different geographic location. Mean differences were assessed either on ANOVA or t-test., Results: Approximately 42% of boys went to bed late at night compared with 37% of girls. When compared to those with <2 h of daily screen time, schoolchildren with 2-4 h of screen time were more likely [odds ratio (OR) = 1.50, 95% confidence interval (CI): 1.07-2.09] to go to bed late at night while those with >4 h of daily screen time were most likely to go to sleep late at night (OR, 1.97; 95%CI: 1.34-2.89). Late bedtime was associated with deprivation in schoolchildren., Conclusions: High screen time and deprivation may explain lateness in bedtime in English schoolchildren. This explanation may vary according to area deprivation and geographic location. Family-centered interventions and parental support are important to reduce screen time, late bedtime and increase sleep duration., (© 2014 Japan Pediatric Society.)

The aim of this study was to determine if month of birth affects performance in 3 tests of physical function in children and adolescents. We measured cardiorespiratory fitness, handgrip strength and lower-body power expressed them relative to (whole year) age then compared scores between calendar year birth-months. We also expressed test performance as the likelihood of achieving criterion-referenced fitness standards. There were significant main effects of birth-month for cardiorespiratory fitness (F=4.54, p<0.001), strength (F=6.81, p<0.001) and power (F=3.67, p<0.001). Children born in November were fitter and more powerful than those born at other times, particularly the summer months (April, May and June). October-born children were stronger than those born in all months except September and November. This relationship was evident despite controlling for decimal age and despite no significant inter-month differences in anthropometric characteristics.There is a clear physical advantage for those born in the autumn and this may explain some of the bias in sports selection attributed to the relative age effect, particularly when the British school-year (September) cut-off is used., (© Georg Thieme Verlag KG Stuttgart · New York.)

Objective: To determine whether active school travel is associated with muscular fitness, which is an emerging marker of youth health., Methods: Handgrip strength, vertical jump and vertical jump peak power were measured in n=6829 English schoolchildren (53% males, age 12.9 ± 1.2 years) between 2007 and 2011. Participants were grouped according to self-reported habitual school travel modality., Results: Cyclists had greater handgrip strength than passive travelers. Vertical jump height was greater in walkers and cyclists compared with passive travelers. Jump peak power was also higher in walkers than in the passive travel group. Compared with passive travelers, cyclists had a higher (age, sex and BMI-adjusted) likelihood of good handgrip strength (OR 1.42, 95%CI;1.14-1.76) and walkers were more likely to have good measures for vertical jump peak power (OR 1.14, 95%CI;1.00-1.29). Cyclists' likelihood of having good handgrip strength remained significantly higher when adjusted for physical activity (OR 1.29, 95%CI;1.08-1.46)., Conclusion: Muscular fitness differs according to school travel habits. Cycling is independently associated with better handgrip strength perhaps due to the physical demands of the activity. Better muscular fitness may provide another health-related reason to encourage active school travel., (Copyright © 2014. Published by Elsevier Inc.)

Objective: To determine if the metabolic cost of the incremental shuttle-walking test protocol is the same as treadmill walking or predicted values of walking-speed equations., Setting: Primary care (community-based cardiac rehabilitation)., Participants: Eight Caucasian cardiac rehabilitation patients (7 males) with a mean age of 67±5.2 years., Primary and Secondary Outcome Measures: Oxygen consumption, metabolic power and energy cost of walking during treadmill and shuttle walking performed in a balanced order with 1 week between trials., Results: Average overall energy cost per metre was higher during treadmill walking (3.22±0.55 J kg/m) than during shuttle walking (3.00±0.41 J kg/m). There were significant post hoc effects at 0.67 m/s (p<0.004) and 0.84 m/s (p<0.001), where the energy cost of treadmill walking was significantly higher than that of shuttle walking. This pattern was reversed at walking speeds 1.52 m/s (p<0.042) and 1.69 m/s (p<0.007) where shuttle walking had a greater energy cost per metre than treadmill walking. At all walking speeds, the energy cost of shuttle walking was higher than that predicted using the American College of Sports Medicine walking equations., Conclusions: The energetic demands of shuttle walking were fundamentally different from those of treadmill walking and should not be directly compared. We warn against estimating the metabolic cost of the incremental shuttle-walking test using the current walking-speed equations., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Objective: The incremental shuttle walking test (ISWT) is used to estimate cardiorespiratory fitness, but data from healthy individuals suggest that demographic and anthropometric measures account for much of the variance in test performance. The aim of this study was to determine whether anthropometric, demographic and selected gait measures also predict ISWT performance (i.e. distance walked) in patients with cardiovascular disease., Design: Observational study., Setting: A community-based cardiac rehabilitation centre (Cohort 1) and a hospital outpatient cardiac rehabilitation programme (Cohort 2)., Participants: Sixteen patients with clinically stable cardiovascular disease (Cohort 1) and 113 patients undergoing cardiac rehabilitation (Cohort 2)., Interventions: Patients in Cohort 1 performed the ISWT on two occasions. Anthropometric data and walking and turning variables were collected. Linear regression analyses were used to identify the predictors of test performance. The authors subsequently attempted to validate the equation created by comparing predicted and actual ISWT values in a larger (n=113) validation sample (Cohort 2)., Main Outcome Measures: Distance walked during ISWT, step length and height., Results: No gait or turning measures were significantly associated with ISWT performance. Distance walked correlated most strongly with step length (r=0.83, P<0.05) and height (r=0.74, P<0.05). Given the similarity of these correlations and the rarity of step length assessment in clinical practice, ISWT performance was predicted using patient's height; this explained 55% of the variance in ISWT performance. Height was also the best predictor in Cohort 2, explaining 17% of test variance (P<0.01). Body mass index explained an additional 3% of variance (P<0.05) in ISWT performance., Conclusions: Routine clinical measures, particularly patient's height, are predictive of ISWT performance. The findings of the present study are in partial agreement with similar studies performed in healthy individuals, and it remains unclear whether the ISWT performance of patients with cardiovascular disease is influenced by the same factors as the ISWT performance of healthy individuals., (Copyright © 2013. Published by Elsevier Ltd.)

The relative age effect (RAE) describes the relationship between an individual's birth month and their level of attainment in sports. There is a clustering of birth dates just after the cutoff used for selection in age-grouped sports, and it is hypothesized that such relatively older sportspeople may enjoy maturational and physical advantages over their younger peers. There is, however, little empirical evidence of any such advantage. This study investigated whether schoolchildren's physical performance differed according to which quarter of the school year they were born in. Mass, stature, body mass index, cardiorespiratory fitness, strength, and power were measured in 10 to 16 year olds (n = 8,550, 53% male). We expressed test performance as age- and sex-specific z-scores based on reference data with age rounded down to the nearest whole year and also as units normalized for body mass. We then compared these values between yearly birth quarters. There were no significant main effects for differences in anthropometric measures in either sex. Girls born in the first quarter of the school year were significantly stronger than those born at other times when handgrip was expressed as a z-score. As z-scores, all measures were significantly higher in boys born in either the first or second yearly quarters. Relative to body mass, cardiorespiratory fitness was higher in boys born in the first quarter and power was higher in those born in the second quarter. The RAE does not appear to significantly affect girls' performance test scores when they are expressed as z-score or relative to body mass. Boys born in the first and second quarters of the year had a significant physical advantage over their relatively younger peers. These findings have practical bearing if coaches use fitness tests for talent identification and team selection. Categorizing test performance based on rounded down values of whole-year age may disadvantage children born later in the selection year. These relatively younger children may be less to gain selection for teams or training programmes.

Objective: Cardiorespiratory fitness is known to be cardioprotective and its association with the components of the metabolic syndrome in children is becoming clearer. The aim of the present study was to examine the extent to which cardiorespiratory fitness may offset the weight-related association with mean arterial pressure (MAP) in schoolchildren., Design: Cross-sectional study., Settings: Schoolchildren from the East of England, U.K., Subjects: A total of 5983 (48% females) schoolchildren, 10 to 16 years of age, had height, weight and blood pressure measured by standard procedures and cardiorespiratory fitness assessed by the 20 m shuttle-run test. Participants were classified as fit or unfit using internationally accepted fitness cut-off points; and as normal weight, overweight or obese based on BMI, again using international cut-off points. Age-adjusted ANCOVA was used to determine the main effects and interaction of fitness and BMI on MAP Z-score. Logistic regression models were used to estimate odds ratios of elevated MAP., Results: Prevalence of elevated MAP in schoolchildren was 14.8% overall and 35.7% in those who were obese-unfit. Approximately 21% of participants were overweight and 5% obese, while 23% were classified as unfit. MAP generally increased across BMI categories and was higher in the aerobically unfit participants. Obese-fit males had lower MAP compared with obese-unfit males (P < 0.001); this trend was similar in females (P = 0.05)., Conclusions: Increasing fitness level may have a positive impact on the weight-related elevations of MAP seen in obese and overweight schoolchildren.

Objectives: The objective of the study is to determine cardiac autonomic control in patients undergoing assessment for and/or LVAD therapy., Methods: Heart rate variability (HRV) was measured in 17 explanted LVAD, 17 implanted LVAD and 23 NYHA III-IV classified chronic heart failure (CHF) patients and ten healthy matched controls under three conditions: supine free breathing, standing and supine controlled breathing. Five measures of HRV were assessed: mean R-R interval (mR-R), high frequency (HF) and low frequency (LF) spectral power, LF in normalised units (LFnu), and LF to HF (LF:HF) ratio., Results: Repeat measures ANOVA showed significant (p < 0.05) differences in HRV between all three conditions within groups. Lower values were observed in CHF for LF(in log natural units) compared with explanted patients (-1.4 [95% CI -2.6 to -0.7], p = 0.04) and controls (-2.1 [-3.5 to -0.7], p = 0.001) and for LF:HF compared with implanted patients under paced breathing conditions (z = -2.7, p = 0.007) and controls in standing (z = -2.9, p = 0.004) and paced breathing conditions (z = -2.3, p = 0.02). However, no significant differences were seen between explanted, implanted and control groups under any condition., Conclusions: Patients implanted with an LVAD and explanted from a LVAD following myocardial recovery demonstrate a more normal dynamic response to autonomic stimuli and have a lower HRV risk profile compared to CHF patients., (© 2013.)

Background: The Physical Activity Questionnaire for Children and Adolescents (PAQ-C/-A) provides general estimates of physical activity levels. Following recent expert recommendations for using the PAQ for population surveillance, the aim of this paper was twofold: first, to describe normative PAQ data for English youth; and second, to determine a criterion-referenced PAQ-score cut-off point., Methods: Participants (n = 7226, 53% boys, 10-15 years) completed an anglicized version of the PAQ. Peak oxygen uptake (VO2peak ) was predicted from PACER lap count according to latest FITNESSGRAM standards and categorized into "at-risk" and "no-risk" for metabolic syndrome. ROC curves were drawn for each age-sex group to identify PAQ scores, which categorized youth into "sufficiently active" versus "low-active" groups, using cardiorespiratory fitness as the criterion-referenced standard., Results: PAQ scores were higher in boys than in girls and declined with age. Mean PAQ score was a significant, albeit relatively weak (area under the curve < 0.7) discriminator between "at-risk" and "no-risk." PAQ scores of ≥2.9 for boys and ≥2.7 for girls were identified as cut-off points, although it may be more appropriate to use lower, age-specific PAQ scores for girls of 13, 14 and 15 years (2.6, 2.4, 2.3, respectively)., Conclusion: The normative and criterion-referenced PAQ values may be used to standardize and categorize PAQ scores in future youth population studies., (© 2013 The Authors. Pediatrics International © 2013 Japan Pediatric Society.)

Exercising in natural, green environments creates greater improvements in adult's self-esteem than exercise undertaken in urban or indoor settings. No comparable data are available for children. The aim of this study was to determine whether so called 'green exercise' affected changes in self-esteem; enjoyment and perceived exertion in children differently to urban exercise. We assessed cardiorespiratory fitness (20 m shuttle-run) and self-reported physical activity (PAQ-A) in 11 and 12 year olds (n = 75). Each pupil completed two 1.5 mile timed runs, one in an urban and another in a rural environment. Trials were completed one week apart during scheduled physical education lessons allocated using a repeated measures design. Self-esteem was measured before and after each trial, ratings of perceived exertion (RPE) and enjoyment were assessed after completing each trial. We found a significant main effect (F (1,74), = 12.2, p<0.001), for the increase in self-esteem following exercise but there was no condition by exercise interaction (F (1,74), = 0.13, p = 0.72). There were no significant differences in perceived exertion or enjoyment between conditions. There was a negative correlation (r = -0.26, p = 0.04) between habitual physical activity and RPE during the control condition, which was not evident in the green exercise condition (r = -0.07, p = 0.55). Contrary to previous studies in adults, green exercise did not produce significantly greater increases in self-esteem than the urban exercise condition. Green exercise was enjoyed more equally by children with differing levels of habitual physical activity and has the potential to engage less active children in exercise.

Background: Exercise training is a key component of cardiac rehabilitation but there is a discrepancy between the high volume of exercise prescribed in trials comprising the evidence base and the lower volume prescribed to UK patients., Objective: To quantify prescribed exercise volume and changes in cardiorespiratory fitness in UK cardiac rehabilitation patients., Methods: We accessed n=950 patients who completed cardiac rehabilitation at four UK centres and extracted clinical data and details of cardiorespiratory fitness testing pre- and post-rehabilitation. We calculated mean and effect size (d) for change in fitness at each centre and converted values to metabolic equivalent (METs). We calculated a fixed-effects estimate of change in fitness expressed as METs and d., Results: Patients completed 6 to 16 (median 8) supervised exercise sessions. Effect sizes for changes in fitness were d=0.34-0.99 in test-specific raw units and d=0.34-0.96 expressed as METs. The pooled fixed effect estimate for change in fitness was 0.52 METs (95% CI 0.51 to 0.53); or an effect size of d=0.59 (95% CI 0.58 to 0.60)., Conclusion: Gains in fitness varied by centre and fitness assessment protocol but the overall increase in fitness (0.52 METs) was only a third the mean estimate reported in a recent systematic review (1.55 METs). The starkest difference in clinical practice in the UK centres we sampled and the trials which comprise the evidence-base for cardiac rehabilitation was the small volume of exercise completed by UK patients. The exercise training volume prescribed was also only a third that reported in most international studies. If representative of UK services, these low training volumes and small increases in cardiorespiratory fitness may partially explain the reported inefficacy of UK cardiac rehabilitation to reduce patient mortality and morbidity.

Background: Screen time (ST) is associated with physical activity (PA) levels. We aimed to investigate the relationship between ST and fitness., Methods: We assessed fitness and daily ST in 7,466 10-16-y-old schoolchildren from the east of England. The differences in fitness between ST groups, and the association between ST and fitness were assessed., Results: ST was negatively associated with fitness in boys of all ages (P < 0.001) and girls in grades 6-9 (P < 0.005). Boys were less likely to be fit if they reported >2 h/d ST (odds ratio (OR): 0.70, 95% confidence interval (CI): 0.58-0.85) or >4 h/d (OR: 0.45, 95% CI: 0.35-0.57) ST, as were girls reporting >4 h/d ST (OR: 0.58, 95% CI: 0.43-0.78). Controlling for PA levels attenuated these odds in boys reporting >2 h/d ST (OR: 0.81, 95% CI: 0.66-0.91) or >4 h/d ST (OR: 0.65, 95% CI: 0.50-0.84) and in girls reporting >4 h/d ST (OR: 0.68, 95% CI: 0.50-0.93)., Conclusion: These first data from English children show a negative association between ST and fitness in youth. Of note, very high levels of daily ST (>4 h) are associated with poor fitness. Some of the associations were mediated by PA levels. Our data support international recommendations to limit ST to <2 h/d; we believe such guidance should be issued in the United Kingdom.

Background: Parental behavior is an important correlate of child health. The aim of this study was to investigate the association between perceived parental physical activity (PA) and schoolchildren's aerobic fitness., Methods: English schoolchildren's (n = 4029, 54% boys, 10.0-15.9 yrs) fitness was assessed by 20 m shuttle run test and categorized using criterion-referenced standards. Parental PA was reported by the child., Results: Boys and girls were more likely to be fit (OR 1.4, 95% CI 1.1-1.8; OR 1.5, 95% CI 1.1-2.0; respectively) if at least 1 parent was perceived as active compared with when neither parents were. Girls were even more likely to be fit (OR 1.8, 95% CI 1.2-2.8) if both parents were active. Associations between parental PA and child fitness were generally stronger when parent and child were of the same gender, although girls with active fathers were more likely (OR 2.5, 95% CI 1.7-3.7) to be fit compared with inactive fathers., Conclusion: Schoolchildren perceiving at least 1 parent as active are more likely to meet health-related fitness standards. Underlying mechanisms remain elusive, but same-gender associations suggest that social rather than genetic factors are of greater importance. Targeting parental PA or at least perceptions of parental PA should be given consideration in interventions aiming to improve child health.

We aim to examine the relationship between metabolic risk (MR) profile and physical activity (PA) with an adult within the household. A total of 4761 schoolchildren (54% boys) aged 10-16 years old were categorized as either at high MR or low MR profile based on their weight and systolic blood pressure status. We assessed the frequency of PA with an adult within the household and fitness. Multilevel regressions were used to determine the likelihood of being at MR in schoolchildren. The proportion of males and females who engage in PA with adults daily was 17.4% and 10.4%, respectively. 16.5% male and 17.2% female did not engage in any PA with adults at all. Compared with those engaging in PA daily with adults in their household, schoolchildren who have reported no such PA were 54% (OR 1.54, 95% CI, 1.07-2.20) likely to have an elevated MR profile. Those who sometimes do PA with adult were 25% (OR 1.25, 95% CI, 0.82-1.93) more likely to have a higher MR profile. After adjusting for PA and fitness, PA with adults remains a determinant of MR profile in males. Compared with those that reported they daily did, schoolchildren were more likely to be unfit if they either sometimes engaged in PA with adults (OR 2.11, 95% CI, 1.44-3.09) or never (OR 2.89, 95% CI, 1.89-4.43). Joint PA with an adult within household could increase schoolchildren's fitness level and may reduce the risk of metabolic diseases., (© 2012 John Wiley & Sons A/S.)

The studies of human and environment interactions usually consider the extremes of environment on individuals or how humans affect the environment. It is well known that physical activity improves both physiological and psychological well-being, but further evidence is required to ascertain how different environments influence and shape health. This review considers the declining levels of physical activity, particularly in the Western world, and how the environment may help motivate and facilitate physical activity. It also addresses the additional physiological and mental health benefits that appear to occur when exercise is performed in an outdoor environment. However, people's connectedness to nature appears to be changing and this has important implications as to how humans are now interacting with nature. Barriers exist, and it is important that these are considered when discussing how to make exercise in the outdoors accessible and beneficial for all. The synergistic combination of exercise and exposure to nature and thus the 'great outdoors' could be used as a powerful tool to help fight the growing incidence of both physical inactivity and non-communicable disease.

Background: Many physical activity intervention programs are unable to sustain long-term improvements in activity levels and are often not cost-effective. The aim of this study was to determine if a low-cost school- and community-centered sports coaching program was able to improve health-related fitness in children., Methods: Children from three schools in socially deprived areas took part in weekly coaching sessions over two 10 week periods during the school year. Coaching was provided by local community-based sports clubs. Body mass index (BMI), jump height, handgrip strength, and 20 m shuttle run test (20mSRT) performance were assessed before and after each of the two intervention periods, to determine short- and long-term changes in health-related fitness. Age- and sex-normalized z-scores were calculated using normative UK reference data for each measure., Results: BMI z-score did not change in the short term, as expected, but importantly was significantly lower at the end of the study. Both handgrip and 20mSRT performance scores increased after the first 10 week period. Only improvements in handgrip were maintained for the whole study period. Jump height actually decreased over the entire study period., Conclusion: There were some notable benefits of this novel, cost-effective, naturalistic intervention but future studies should examine seasonal variation and motivational factors as potential confounding variables., (© 2012 The Authors. Pediatrics International © 2012 Japan Pediatric Society.)

Objective: To investigate the influence of gait parameters including step length and walking speed during performance of the 6-minute walking test (6MWT) in patients with chronic heart failure (CHF)., Design: Observational study., Setting: Specialist heart failure clinic., Participants: Patients with CHF and aged-matched, apparently healthy controls., Interventions: Each patient and control performed a 6MWT following a standardised protocol in a 15m corridor. The number of steps (defined as step from left foot to right foot) taken every 15m was counted, and reported as minute-by-minute changes in 6MWT performance. In addition, minute-by-minute changes in time taken to complete 15m and mean walking speed throughout the test were calculated., Main Outcome Measures: Walking speed and step length., Results: Thirty patients with CHF {87% males; mean age 75 [standard deviation (SD) 8] years} and 10 healthy controls [80% males; mean age 77 (SD 11) years] undertook the 6MWT. For the CHF group, the mean distance walked was 309 (SD 48)m and the peak Borg score was 12 (SD 1). For the controls, the mean distance walked was 334 (SD 138)m and the peak Borg score was 12 (SD 1). Patients with CHF showed no significant minute-by-minute changes in step length or walking speed over the course of the 6MWT. In the first 5minutes, healthy controls had a longer step length and faster walking speed than patients with CHF [step length: mean difference in the first minute was 0.03m, 95% confidence interval (CI) of the difference 0.01 to 0.05m; P=0.02; walking speed: mean difference in the first minute 0.04m/second, 95% CI of the difference 0.02 to 0.07m/second; P=0.01]. A multiple linear regression analysis demonstrated that body mass index (P=0.02) was the most important predictor of 6MWT performance., Conclusion: Patients with CHF have a shorter step length and walk more slowly than controls during the 6MWT. Altered gait mechanics may contribute to limited exercise capacity in patients with CHF., (Copyright © 2011 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.)

Previously studies have shown that nature improves mood and self-esteem and reduces blood pressure. Walking within a natural environment has been suggested to alter autonomic nervous system control, but the mechanisms are not fully understood. Heart rate variability (HRV) is a non-invasive method of assessing autonomic control and can give an insight into vagal modulation. Our hypothesis was that viewing nature alone within a controlled laboratory environment would induce higher levels of HRV as compared to built scenes. Heart rate (HR) and blood pressure (BP) were measured during viewing different scenes in a controlled environment. HRV was used to investigate alterations in autonomic activity, specifically parasympathetic activity. Each participant lay in the semi-supine position in a laboratory while we recorded 5 min (n = 29) of ECG, BP and respiration as they viewed two collections of slides (one containing nature views and the other built scenes). During viewing of nature, markers of parasympathetic activity were increased in both studies. Root mean squared of successive differences increased 4.2 ± 7.7 ms (t = 2.9, p = 0.008) and natural logarithm of high frequency increased 0.19 ± 0.36 ms(2) Hz(-1) (t = 2.9, p = 0.007) as compared to built scenes. Mean HR and BP were not significantly altered. This study provides evidence that autonomic control of the heart is altered by the simple act of just viewing natural scenes with an increase in vagal activity.

Objective: To determine the temporal relationships screen-time and physical activity have with cardiorespiratory fitness., Method: Measures were made over two years (2008-2010) in 1500 participants aged 11.5 (SD 0.5) years at baseline., Results: Tracking coefficients were low-to-moderate for all measures. At follow-up, 25% of participants moved from having low (<2h) to high (≥ 2 h) daily screen-time and 6% became unfit according to FITNESSGRAM standards. Baseline screen-time was the strongest univariate predictor of becoming unfit. Multivariate analysis controlling for decimal age, BMI and deprivation confirmed baseline screen-time as the strongest independent predictor of becoming unfit over the 2-year study period (OR 2.4; 95%CI:1.4-4.0). Current (OR 2.3; 95%CI:1.3-4.0) and previous (OR 1.7; 95%CI:1.0-2.9) physical activity levels also independently predicted becoming unfit., Conclusion: There is currently no guidance for limiting screen-time in UK children. These longitudinal data add to the cross-sectional evidence of lower physical activity and fitness in children reporting ≥ 2 h daily screen-time. More importantly, these data demonstrate that high screen-time during childhood is an independent predictor of lower cardiorespiratory fitness in adolescence., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Objective: The most prevalent sedentary behaviours in children and adolescents are engagement with small screen media (screen-time) and passive travel (by motorised vehicle). The objective of this research was to assess the independence of these behaviours from one another and from physical activity as predictors of cardiorespiratory fitness in youth., Methods: We measured cardiorespiratory fitness in n=6819 10-16 year olds (53% male) who self-reported their physical activity (7-day recall) school travel and screen time habits. Travel was classified as active (walking, cycling) or passive; screen time as <2 h, 2-4 h or >4 h., Results: The multivariate odds of being fit were higher in active travel (Boys: OR 1.32, 95% CI: 1.09-1.59; Girls: OR 1.46, 1.15-1.84) than in passive travel groups. Boys reporting low screen time were more likely to be fit than those reporting >4 h (OR 2.11, 95% CI: 1.68-2.63) as were girls (OR 1.66, 95% CI: 1.24-2.20). These odds remained significant after additionally controlling for physical activity., Conclusion: Passive travel and high screen time are independently associated with poor cardiorespiratory fitness in youth, and this relationship is independent of physical activity levels. A lifestyle involving high screen time and habitual passive school travel appears incompatible with healthful levels of cardiorespiratory fitness in youth., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Physical activity (PA) and deprivation are major determinants of health. We estimated the prevalence of high screen time (ST) among English youth and examined whether deprivation mediated the relationship between ST and PA., Methods: It is a cross-sectional study of 6240 participants (53% boys, aged 10-15 years) enrolled in the East of England Healthy Hearts study. The participants were categorized into three groups based on daily ST: <2, 2-4 or >4 h. Participants were classified as 'active' or 'inactive' based on PA z-scores., Results: Prevalence of >2 h ST was 36%. Participants reporting <2 h daily ST were more likely to be active than those reporting 2-4 h (adjusted OR: 1.51, 95% CI: 1.26-1.82, P< 0.001) or >4 h (adjusted OR: 2.26, 95% CI: 1.91-2.67, P< 0.001). Analysis of covariance demonstrated a significant main effect for ST on PA (F = 85.7, P< 0.001) with lower PA in each ascending ST group (P< 0.001). Deprivation was not significantly associated with PA and did not mediate the relationship between ST and PA., Conclusions: There is high prevalence of >2 h ST in English schoolchildren. PA is lower in children reporting 2-4 versus <2 h daily ST and lower still in those classified as heavy users (>4 h) independent of deprivation.

Purpose: Schoolchildren who cycle to school have higher cardiorespiratory fitness (CRF) than those who are driven or use public transport. The purpose of this study was to determine whether recreational cycling is similarly associated with CRF., Methods: Participants were 5578 (54% males) English schoolchildren (10.0-15.9 yr). All reported frequency of recreational cycling events via 7-d recall. Responses were categorized as follows: "noncyclists" = 0, "occasional cyclists" = 1-4, or "regular cyclists" = 5+ (times per week). CRF was assessed using the 20-m shuttle run test with performance classified as "fit" or "unfit" based on FITNESSGRAM standards., Results: Overall, 26% of males and 46% of females were noncyclists. Compared with noncyclists, the 40% of males and 42% of females classified as occasional cyclists were more likely to be fit (males: odds ratio (OR) = 1.30, 95% confidence interval (CI) = 1.07-1.59; females: OR = 1.41, 95% CI = 1.13-1.76). Regular cyclists (34% males and 12% females) had a greater likelihood still of being classified as fit (males: OR = 1.58, 95% CI = 1.29-1.95; females: OR = 1.55, 95% CI = 1.09-2.20). No odds remained significant after adjusting for physical activity. Removal of participants who cycled to school had little overall effect on the likelihood of being classified as being fit., Conclusions: Previous research has focused only on young people's commuter cycling habits, at the expense of the more common activity of recreational cycling. Recreational cycling may provide an alternative target for interventions to increase physical activity and improve CRF youth. Recreational cycling could potentially serve as a way to gain cycling confidence and establish habits that act as precursors to commuter cycling.

Aims: There is evidence for lower physical activity (PA) in rural adults; it is important to evaluate how the environment influences the PA of children and adolescents., Methods: We compared the PA of 6485 English 10-15.9 year olds according to two systems for classifying the immediate environment. System one compared urban and rural areas. System two compared urban, town and fringe, and rural areas. Analyses were carried out separately for children (<13 years) and adolescents (>13 years)., Results: Rural children were more active than those from urban areas (OR 1.38, 95% CI 1.15-1.66) as were adolescents (OR 1.30, 95% CI 1.11-1.51). Using trilateral division, children were more active if they lived in town and fringe (OR 1.32, 95% CI 1.03-1.67) or rural (OR 1.45, 95% CI 1.14-1.84) areas compared with urban areas. Adolescents from town and fringe areas were more active than urban dwellers (OR 1.50, 95% CI 1.24-1.81). Rural adolescents' PA did not differ from urban dwellers'., Conclusions: Rural environments support PA in children but not that of adolescents. Town and fringe areas with mixed elements of rural and urban land use appear to facilitate and sustain PA in both children and adolescents.

Heart rate variability (HRV) is a known risk factor for mortality in both healthy and patient populations. There are currently no normative data for short-term measures of HRV. A thorough review of short-term HRV data published since 1996 was therefore performed. Data from studies published after the 1996 Task Force report (i.e., between January 1997 and September 2008) and reporting short-term measures of HRV obtained in normally healthy individuals were collated and factors underlying discrepant values were identified. Forty-four studies met the pre-set inclusion criteria involving 21,438 participants. Values for short-term HRV measures from the literature were lower than Task Force norms. A degree of homogeneity for common measures of HRV in healthy adults was shown across studies. A number of studies demonstrate large interindividual variations (up to 260,000%), particularly for spectral measures. A number of methodological discrepancies underlined disparate values. These include a systematic failure within the literature (a) to recognize the importance of RR data recognition/editing procedures and (b) to question disparate HRV values observed in normally healthy individuals. A need for large-scale population studies and a review of the Task Force recommendations for short-term HRV that covers the full-age spectrum were identified. Data presented should be used to quantify reference ranges for short-term measures of HRV in healthy adult populations but should be undertaken with reference to methodological factors underlying disparate values. Recommendations for the measurement of HRV require updating to include current technologies., (©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.)

Objectives: The aim of this study was to assess associations between habitual school-day breakfast consumption, body mass index (BMI), physical activity (PA) and cardiorespiratory fitness (CRF)., Methods: BMI, PA and CRF were measured in 4326 schoolchildren aged 10-16 years. Participants were classified as obese or non-obese, as having low or high PA and CRF. Habitual school-day breakfast consumption was assessed by a questionnaire and classified as never, sometimes or always., Results: Participants who sometimes ate breakfast were more likely to be obese than those who always did (P<0.05). Boys who never ate breakfast were more likely to have low PA odds ratio (OR) 2.17, 95% CI 1.48-3.18) and low CRF (OR 2.02, 95% CI 1.40-2.93) than those who always did. Compared with those who always did so, girls were more likely to have low PA if they sometimes (OR 1.39, 95% CI 1.13-1.70) or never (1.48 95% CI 1.06-2.05) ate breakfast, but the likelihood of low CRF was not different between groups., Conclusions: Habitual breakfast consumption is associated with healthy BMI and higher PA levels in schoolchildren. In boys, regularly eating breakfast is also associated with higher levels of CRF. The higher PA observed in habitual breakfast eaters may explain the higher CRF values observed. These positive health behaviours and outcomes support the encouragement of regular breakfast eating in this age group.

Objectives: Identify the underlying role of resting heart rate variability (HRV) in the hearts response to graded exercise testing (GXT)., Methods: Resting 5-min HRV and heart rate (HR) measurements were made in 33 volunteers (19 males, median age 34, range 25-63 years and 14 females median age 48, range 21-63 years). Measures of VO2 peak and HR obtained during a maximal GXT and heart rate recovery (HRR) post-GXT were assessed for associations with resting HRV. Differences and effect size (d) for measures of HRV were assessed between groups based on established risk cut-points for resting, exercise and recovery HR responses., Results: Small associations were observed for the majority of resting HRV and GXT HR responses (best r value = -0.27, P > 0.05). Measures of HRV demonstrated moderate associations with HRR (best r value = 0.46, P < 0.05) and were able to predict a negative risk HRR. In contrast to other dependent variables, measures of HRV were consistently able to demonstrate significant and moderate to large (d = 0.9-2.0) differences between groups based on literature defined prognostic HR cut-points., Interpretation: Small associations with HR responses to exercise prevent their accurate prediction from resting HRV. Data support the use of vagally mediated resting HRV in predicting better HRR. Lower resting autonomic modulations underlined high risk resting and exercise HR responses. Resting short-term HRV measurements should be considered when assessing cardiac autonomic health from the HR response before, during and/or after exercise.