Transient endothelial dysfunction induced by sugar-sweetened beverage consumption may be attenuated by a single bout of aerobic exercise.

BACKGROUND: This study assessed whether aerobic exercise would attenuate microvascular endothelial dysfunction induced by commercial sugar-sweetened beverage (SSB) consumption. METHODS: Eleven healthy males participated in this randomized, single-blind crossover study. Cutaneous microvascular endothelial function was assessed using laser speckle contrast imaging coupled with post-occlusive reactive hyperemia before and after a) consumption of water; b) consumption of a commercial SSB; c) 30min of aerobic exercise followed by water consumption; and d) 30 minutes of aerobic exercise followed by SSB consumption. Blood glucose and arterial pressure responses were also monitored. Volumes of water and SSB consumed (637.39±29.15 mL) were individualized for each participant, ensuring SSB consumption delivered 1 g of sucrose per kg of body weight. Exercise was performed at 75% of the maximal oxygen uptake heart rate. RESULTS: Compared to water consumption, the commercial SSB elevated blood glucose concentrations in both sedentary (4.69±0.11 vs. 7.47±0.28 mmol/L, P<0.05) and exercised states (4.95±0.13 vs. 7.93±0.15 mmol/L, P<0.05). However, the decrease in microvascular endothelial function observed following sedentary SSB consumption, expressed as the percentage increase from baseline (208.60±22.40 vs. 179.83±15.80%, P=0.01) and the change in peak hyperemic blood flux from basal to post-intervention assessments (-0.04±0.03 vs. -0.12±0.02 ΔCVC, P=0.01), was attenuated following 30min of aerobic exercise. CONCLUSIONS: To our knowledge, this is the first study to provide evidence that a single bout of aerobic exercise may prevent transient SSB-mediated microvascular endothelial dysfunction.

Effects of a Multi-Disciplinary Lifestyle Intervention on Cardiometabolic Risk Factors in Young Women with Abdominal Obesity: A Randomised Controlled Trial.

BACKGROUND: Young women are under-represented in cardiovascular disease research, with obesity and cardiometabolic risk factor interventions generally targeting older adults. Furthermore, appropriate study designs for young women remain uncertain. This study aimed to assess the impact of a 12 week multi-disciplinary lifestyle intervention on cardiometabolic risk factors in premenopausal women with abdominal obesity. METHODS: Women aged 18-30 y with abdominal obesity [waist circumference (WC) ≥ 80 cm] were randomised to a 12 week lifestyle intervention (n = 26) of physical activity, nutrition education and cognitive behavioural therapy, or a wait-list control group (n = 17). Both groups completed anthropometric, biochemical, nutrition and fitness testing, at pre (0 weeks) and post (12 weeks), with intervention participants completed follow-up testing at 24 weeks. RESULTS: Results from a linear mixed model showed no between-group differences, other than increased physical activity in the intervention group, at post. In the intervention group alone, positive within-group changes were observed in WC, waist-hip-ratio (WHR), waist-height-ratio (WHtR), resting heart rate, blood pressure, predicted VO2max, and total energy intake. Most changes were maintained at 24 weeks post-intervention. Similar within-group improvements were observed in control participants in WC, WHR, WHtR, and systolic blood pressure but no changes were detected in physical activity and nutrition. CONCLUSIONS: Cardiometabolic risk factors were decreased as a result of a lifestyle intervention in young women with abdominal obesity. It is difficult to describe observations in the control group without greater understanding of the behaviour of wait-list participants. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry ACTRN12612001017819.

Young Women With Abdominal Obesity Have Subclinical Myocardial Dysfunction.

BACKGROUND: Abdominal obesity is an independent risk factor for cardiovascular disease. The effect of abdominal obesity on myocardial function in young obese women remains unknown. Therefore, we aimed to investigate cardiac morphology and function, myocardial deformation, and mechanical indices, in young women with and without abdominal obesity. METHODS: Cross-sectional analyses of 39 women with abdominal obesity (waist circumference ≥ 80 cm) and 33 nonobese control subjects (waist circumference < 80 cm) aged 18-30 years underwent conventional echocardiographic measures of cardiac morphology and function together with tissue Doppler, and 2-dimensional speckle tracking measures of myocardial deformation and mechanics. Cardiometabolic risk factors including anthropometric, hypertension, biochemistry, and fitness were also assessed. RESULTS: Standard echocardiography results for cardiac morphology and function were similar between groups, with the exception of larger left atrial dimensions in women with abdominal obesity (P ≤ 0.05). Compared with control subjects, women with abdominal obesity also demonstrated reduced systolic and diastolic mitral annular plane velocities, increased left atrial pressure surrogates (E/diastolic mitral annular plane velocity), and prolonged timing measures of diastolic function including isovolumic relaxation time and transmitral deceleration time (P ≤ 0.05). In addition, longitudinal strain and diastolic strain rate were reduced in women with abdominal obesity (P ≤ 0.05) but circumferential deformation and myocardial mechanics (twist indices and rotation) were preserved. Markers of abdominal obesity retained an independent direct correlation with parameters of cardiac dysfunction, explaining 12%-39% of the overall variability. CONCLUSIONS: A young, otherwise healthy group of women with abdominal obesity displayed subclinical cardiac dysfunction indicated using selected tissue Doppler imaging and speckle tracking echocardiography measures.

Cardiometabolic and behavioural risk factors in young overweight women identified with simple anthropometric measures.

OBJECTIVES: This study aimed to (1) investigate cardiometabolic risk markers in young women (18-30 years) with overweight/obesity, and (2) establish whether the measures of waist circumference and body mass index possess similar associations of cardiometabolic risk. DESIGN: Cross-sectional. METHODS: Cardiometabolic risk factors including, anthropometric, metabolic syndrome markers, biochemical, and other health/fitness indicators were assessed in women when classified as overweight/obese by waist circumference [waist circumference 91.9 ± 10.1 cm, age 22.3 ± 3.5 years, n = 38] versus control [n = 30, waist circumference 71.4 ± 3.5 cm, age 20.1 ± 0.9 years], and when classified by body mass index [n=35, body mass index 32.2 ± 5.2 kg m(2), age 22.5 ± 3.6 years] versus control [body mass index 21.7 ± 1.9 kg m(2), age 20.1 ± 0.9 years, n=33]. RESULTS: Compared with controls, women with overweight/obesity (classified by waist circumference or body mass index) displayed elevated body mass, systolic blood pressure and homeostasis model assessment of insulin resistance, and reduced estimated [Formula: see text] and weekly physical activity, with no differences in self-reported energy intake. The unadjusted odds ratio of being classified with overweight/obesity and an elevated homeostasis model assessment of insulin resistance and/or less than recommended physical activity ranged between 5.1 and 10.0. Receiver operator characteristic curves indicated waist circumference, body mass index and waist-to-height ratio cut-off points of ≥ 84.2 cm, ≥ 30.6 kg m(-2) and ≥ 0.5, respectively, for homeostasis model assessment of insulin resistance, and ≥ 80.6 cm, ≥ 25.2 kg m(-2) and ≥ 0.46, respectively, for less than recommended physical activity. CONCLUSIONS: Waist circumference and body mass index have similar associations with cardiometabolic risk, with greater homeostasis model assessment of insulin resistance and lower physical activity, rather than differences in traditional metabolic syndrome markers, observed in young women with overweight/obesity.

Caffeine and performance in clay target shooting.

Controversy surrounds the influence that caffeine has on accuracy and cognitive performance in precision activities such as shooting and archery. The aim of this study was to assess the effects of two doses of caffeine on shooting performance, reaction time, and target tracking times in the sport of clay target shooting. A randomized, double-blind, placebo-controlled design was undertaken by seven elite male shooters from the double-trap discipline. Three intervention trials (2 mg caffeine . kg(-1) body mass (BM); 4 mg caffeine . kg(-1) BM; placebo) were undertaken, in which shooters completed four rounds per trial of 50 targets per round. Performance accuracy (score) and digital video footage (for determination of reaction time and target tracking times) were gathered during competition. Data were analysed using repeated-measures analysis of variance. No differences in shooting accuracy, reaction time or target tracking times among the three intervention trials or across the four rounds within each intervention were observed (P > 0.05). The results indicate that ingestion of < or =4 mg caffeine . kg(-1) BM does not provide performance benefits to elite performers of clay target shooting in the double-trap discipline.