Parental views of children's physical activity: a qualitative study with parents from multi-ethnic backgrounds living in England.

BACKGROUND: Guidelines recommend children and young people participate in at least 60 min of physical activity (PA) every day, however, findings from UK studies show PA levels of children vary across ethnic groups. Since parents play an instrumental role in determining children's PA levels, this article aims to explore parental views of children's PA in a multi-ethnic sample living in a large city in the North-West of England. METHODS: Six single-ethnic focus groups were conducted with 36 parents of school-aged children (4 to 16 years) with a predominantly low socio-economic status (SES). Parents self-identified their ethnic background as Asian Bangladeshi (n = 5), Black African (n = 4), Black Somali (n = 7), Chinese (n = 6), White British (n = 8) and Yemeni (n = 6). Focus group topics included understanding of PA, awareness of PA guidelines, knowledge of benefits associated with PA and perceived influences on PA in childhood. Data were analysed thematically using QSR NVivo 9.0. RESULTS: Parents from all ethnic groups valued PA and were aware of its benefits, however they lacked awareness of PA recommendations, perceived school to be the main provider for children's PA, and reported challenges in motivating children to be active. At the environmental level, barriers to PA included safety concerns, adverse weather, lack of resources and lack of access. Additional barriers were noted for ethnic groups from cultures that prioritised educational attainment over PA (Asian Bangladeshi, Chinese, Yemeni) and with a Muslim faith (Asian Bangladeshi, Black Somali, Yemeni), who reported a lack of culturally appropriate PA opportunities for girls. CONCLUSION: Parents from multi-ethnic groups lacked awareness of children's PA recommendations and faced barriers to promoting children's PA out of school, with certain ethnic groups facing additional barriers due to cultural and religious factors. It is recommended children's PA interventions address influences at all socio-ecological levels, and account for differences between ethnic groups.

Reproducibility of Cutaneous Vascular Conductance Responses to Slow Local Heating Assessed Using seven-Laser Array Probes.

OBJECTIVE: Gradual local heating of the skin induces a largely NO-mediated vasodilatation. However, use of this assessment of microvascular health is limited because little is known about its reproducibility. METHODS: Healthy volunteers (n = 9) reported twice to the laboratory. CVC, derived from laser Doppler flux and mean arterial pressure, was examined in response to a standardized local heating protocol (0.5°C per 150 second from 33°C to 42°C, followed by 20 minutes at 44°C). Skin responses were examined at two locations on the forearm (between-site). Heating was repeated after a break of 24-72 hours (between-day). Reproducibility of skin responses at 33-42°C is presented for absolute CVC and relative CVC responses corrected for maximal CVC at 44°C (%CVCmax ). RESULTS: Between-day reproducibility of baseline CVC and %CVCmax for both sites was relatively poor (22-30%). At 42°C, CVC and %CVCmax responses showed less variation (9-19%), whilst absolute CVC responses at 44°C were 14-17%. Between-day variation for %CVCmax increased when using data from site 1 on day 1, but site 2 on the subsequent day (25%). CONCLUSION: Day-to-day reproducibility of baseline laser Doppler-derived skin perfusion responses is poor, but acceptable when absolute and relative skin perfusion to a local gradual heating protocol is utilized and site-to-site variation is minimized.

Exercise training in polycystic ovarian syndrome enhances flow-mediated dilation in the absence of changes in fatness.

INTRODUCTION: Polycystic ovarian syndrome (PCOS) is associated with an adverse cardiovascular disease (CVD) profile. A surrogate marker for CVD risk is endothelial dysfunction. Limited studies exist examining the cardiovascular and metabolic effects of exercise in PCOS and specifically its impact on endothelial function. Therefore, the aim of the current study was to investigate the impact of exercise on endothelial function, in parallel with body composition, insulin resistance, and cardiopulmonary fitness in PCOS. METHODS: Ten women with PCOS (27 yr, 95% confidence interval [CI] = 23-32; 31 kg·m⁻², 95% CI = 28-34) completed a 16-wk exercise (EX) program, and seven women with PCOS (29 yr, 95% CI = 24-35; 35 kg·m⁻², 95% CI = 31-40) undertook conventional care (CC) following lifestyle advice. Brachial artery endothelial function was assessed pre- and postintervention using flow-mediated dilation adjusted for variability in baseline diameter. Visceral and abdominal subcutaneous adipose tissue was assessed using whole-body magnetic resonance imaging and ¹H magnetic resonance spectroscopy quantified liver fat. Cardiorespiratory fitness, glycemic control, hormone, and lipid profiles were also assessed. Data were analyzed using covariate-controlled generalized estimating equations. RESULTS: At follow-up, EX improved flow-mediated dilation by 3.6% (95% CI = 0.5-6.7, P = 0.03) more than CC. There was a parallel improvement in cardiorespiratory fitness of 4.7 mL·kg⁻¹·min⁻¹ (95% CI = 1.4-7.9, P < 0.001) with EX versus CC. These changes were not explained by changes in visceral adipose tissue, subcutaneous adipose tissue, liver fat or insulin resistance. CONCLUSIONS: Supervised exercise in women with PCOS improves endothelial function, an adaptation associated with reduced CVD risk. This change occurs independent of changes in body weight or composition. The success of public health interventions in this patient group should not be solely judged by weight loss.

Effect of ischemic preconditioning on lactate accumulation and running performance.

PURPOSE: Repeated bouts of ischemia followed by reperfusion (i.e., ischemic preconditioning (IPC)) protect against damage after a myocardial infarction. Recent observational data indicate that IPC improves exercise performance. However, no previous study has examined potential underlying mechanisms for this effect of IPC. Therefore, we examined the potential of IPC to improve 5-km running time trial performance and reduce lactate accumulation during an incremental exercise test. METHODS: In a randomized, crossover study, 13 healthy men performed running exercise, which was preceded by IPC (4 × 5-min 220 mm Hg bilateral leg occlusion) or a control intervention (C) (4 × 5-min 20 mm Hg bilateral leg occlusion). Participants performed a graded maximal treadmill running test, starting with five 3-min submaximal stages (10-14 km·h), followed by increments of 1 km·h every 2 min to 16 km·h, followed by an incline of the treadmill of 2% every 2 min. Blood lactate was examined at each 3-min stage. After 45 min of rest in the supine position, subjects then performed a 5-km running time trial. RESULTS: We found similar submaximal gas parameters during running exercise with both interventions. The overall increase in blood lactate during the submaximal stages was 1.07 ± 0.11 mmol·L lower when exercise was preceded with IPC versus C (P = 0.023). The 5-km running time trial was completed in a time that was 34 s faster after IPC versus C (95% confidence interval, 5-64 s; P = 0.027). CONCLUSION: IPC improves 5-km time trial performance in healthy male individuals. Moreover, we found that IPC is associated with an attenuated rise in blood lactate concentration at submaximal level during an incremental running test. This could indicate that IPC allows for higher work rates and thus improves time trial performance.

Effects of supra-physiological changes in human ovarian hormone levels on maximum force production of the first dorsal interosseus muscle.

The purpose of this study was to investigate the effects of supra-physiological changes in ovarian hormone levels on maximum force production in two conditions, one physiological (pregnancy) and one pseudo-physiological (in vitro fertilization (IVF) treatment). Forty IVF patients were tested at four distinct stages of treatment and 35 women were tested during each trimester of pregnancy and following parturition. Maximum voluntary isometric force per unit cross-sectional area of the first dorsal interosseus muscle was measured. Plasma concentrations of total and bioavailable oestradiol and testosterone were measured, in addition to the total concentrations of progesterone and human chorionic gonadotropin. Despite significant changes in the concentrations of total progesterone, 17beta-oestradiol, bioavailable oestradiol and testosterone between phases, strength did not change significantly throughout IVF treatment (1.30+/-0.29, 1.16+/-0.38, 1.20+/-0.29 and 1.26+/-0.34 N mm-2, respectively, in the 4 phases of IVF treatment). Force production was significantly higher during the second trimester of pregnancy than following childbirth (1.33+/-0.20 N mm-2 at week 12 of pregnancy, 1.51+/-0.42 N mm-2 at week 20, 1.15+/-0.26 N mm-2 at week 36 and 0.94+/-0.31 N mm-2 at week 6 postnatal) but was not significantly correlated with any of the hormones measured. These data suggest that extreme changes in the concentrations of reproductive hormones do not affect the maximum force-generating capacity of young women.