Associations between cardiorespiratory fitness and the metabolic syndrome in British men

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

Effects of exercise-based cardiac rehabilitation on cardiorespiratory fitness: A meta-analysis of UK studies

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  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

A randomised controlled trial of 1- versus 2-day per week formats of Nordic hamstring training on explosive athletic tasks in prepubertal soccer players

Purpose: This randomised controlled trial examined the effect of volume-equated programmes of Nordic hamstring exercise (NHE) training, executed at frequencies of 1- or 2-days per week, on explosive athletic tasks (30 m sprint, 15 m manoeuvrability and standing long jump [SLJ]) in male youth soccer players (mean age: 10.3 ± 0.5 years). Materials and methods: Players were divided into an experimental group (n=31) which was further subdivided into 1-day (n=16) and 2-days (n=15) per week training conditions, and a control group (n=14). Results: There were significant group-by-time interactions for 30-m sprint (p<0.001, d=0.6), SLJ (p=0.001, d=1.27) and 15 m manoeuvrability (p<0.001, d=0.61). The experimental group demonstrated small to moderate effect sizes in 30-m sprint (d=0.42, p=0.077), SLJ (d=0.97, p<0.001) and 15 m manoeuvrability (d=0.61, p<0.001). The control group showed small significant performance decrements or no change in these variables. There were no significant differences between the 1-day and 2-day training groups. In two of the three tests (30 m sprint, SLJ) the 2-day group demonstrated larger effect sizes. Conclusion: The NHE enhances explosive athletic task performance in prepubertal youth soccer players and there may be only small advantages to spreading training over two days instead of one

Implementation of a Community-Based Mind-Body (Tae-Bo) Physical Activity Programme on Health-Related Physical Fitness in Rural Black Overweight and Obese Women with Manifest Risk Factors for Multimorbidity.

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

Fitness Changes in Adolescent Girls Following In-School Combined Aerobic and Resistance Exercise: Interaction With Birthweight.

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

A Repeated Measures Experiment of Green Exercise to Improve Self-Esteem in UK School Children

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. © 2013 Reed et al

Characterization of the Metabolically Healthy Phenotype in Overweight and Obese British Men

We calculated the prevalence of the metabolically healthy but obese (MHO) phenotype in (n=9 177) British men (age 48.9±7.4 years) attending preventive health screening between 2000 and 2009. We examined differences in cardiorespiratory fitness (Fitness) and self-reported physical activity levels, according to whether the men were metabolically healthy (<2 components of the metabolic syndrome), and by BMI category (normal-weight, over-weight, obese). Fitness was estimated from treadmill exercise as VO2peak and classified as: Low, Moderate, or High using age-specific cut-offs. We identified 21.6% of our sample as obese, of whom 83.1% were metabolically healthy. Compared with the metabolic unhealthy obese (MUO; 3.7% of sample), MHO phenotypes were fitter (effect size d=0.21) and were more physically active (d=0.31). Logistic regression showed high fitness (OR=2.40, 95%CI 1.38-4.19), and being physically active (OR=1.71, 95% CI 1.14-2.56) to be independently associated with the MHO phenotype. Our findings agree with US data suggesting that higher cardiorespiratory fitness is a characteristic of the MHO phenotype. Our finding that meeting physical activity guidelines was associated with the MHO phenotype independent of fitness is, however, novel. If confirmed, our findings indicate that public health messages that en-courage active lifestyles to promote fitness should be encouraged regardless of weight sta-tus

The SIMAC study: A randomized controlled trial to compare the effects of resistance training and aerobic training on the fitness and body composition of Colombian adolescents.

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

European fitness landscape for children and adolescents: updated reference values, fitness maps and country rankings based on nearly 8 million test results from 34 countries gathered by the FitBack network

Objectives (1) To develop reference values for health-related fitness in European children and adolescents aged 6–18 years that are the foundation for the web-based, open-access and multilanguage fitness platform (FitBack); (2) to provide comparisons across European countries. Methods This study builds on a previous large fitness reference study in European youth by (1) widening the age demographic, (2) identifying the most recent and representative country-level data and (3) including national data from existing fitness surveillance and monitoring systems. We used the Assessing Levels of PHysical Activity and fitness at population level (ALPHA) test battery as it comprises tests with the highest test–retest reliability, criterion/construct validity and health-related predictive validity: the 20 m shuttle run (cardiorespiratory fitness); handgrip strength and standing long jump (muscular strength); and body height, body mass, body mass index and waist circumference (anthropometry). Percentile values were obtained using the generalised additive models for location, scale and shape method. Results A total of 7 966 693 test results from 34 countries (106 datasets) were used to develop sex-specific and age-specific percentile values. In addition, country-level rankings based on mean percentiles are provided for each fitness test, as well as an overall fitness ranking. Finally, an interactive fitness platform, including individual and group reporting and European fitness maps, is provided and freely available online (www.fitbackeurope.eu). Conclusion This study discusses the major implications of fitness assessment in youth from health, educational and sport perspectives, and how the FitBack reference values and interactive web-based platform contribute to it. Fitness testing can be conducted in school and/or sport settings, and the interpreted results be integrated in the healthcare systems across Europe