Increases in vagal-related indices of resting and post-exercise HRV, post-exercise HRR, and HR acceleration are evident when positive adaptation to training has occurred, allowing for increases in performance. However, increases in post-exercise HRV and HRR also occur in response to overreaching, demonstrating that additional measures of training tolerance may be required to determine whether training-induced changes in these parameters are related to positive or negative adaptations. Resting HRV is largely unaffected by overreaching, although this may be the result of methodological issues that warrant further investigation. HR acceleration appears to decrease in response to overreaching training, and thus may be a potential indicator of training-induced fatigue.

Objective: Impaired endothelial function in obesity may reduce blood flow to sites of metabolism, contributing to impaired fat oxidation and insulin resistance. This study investigated the effects of cocoa flavanols and regular exercise, interventions known to improve endothelial function, on cardiometabolic function and body composition in obese individuals. Design: Overweight and obese adults were randomly assigned to high-flavanol cocoa (HF, 902 mg flavanols), HF and exercise, low-flavanol cocoa (LF, 36 mg flavanols), or LF and exercise for 12 weeks (exercise duration was 3 Â 45 min per week at 75% of age-predicted maximum heart rate). Body composition was assessed by dual-energy X-ray absorptiometry at 0 and 12 weeks. Brachial artery flow-mediated dilatation (FMD), supine blood pressure (BP) and fasting plasma insulin, and glucose levels were assessed at 0, 6 and 12 weeks, respectively. Insulin sensitivity/resistance was determined using the modified homeostasis model assessment of insulin resistance (HOMA2). Results: A total of 49 subjects (M ¼ 18; F ¼ 31) completed the intervention. Baseline averages were as follows: body mass index ¼ 33.5 kg/m 2 ; BP ¼ 123/76 mm Hg; HOMA2 ¼ 2.4; FMD ¼ 4.3%; rate of fat oxidation during exercise ¼ 0.34 g min À1 ; abdominal fat ¼ 45.7% of total abdominal mass. Compared to LF, HF increased FMD acutely (2 h post-dose) by 2.4% (Po0.01) and chronically (over 12 weeks; Po0.01) by 1.6% and reduced insulin resistance by 0.31% (Po0.05), diastolic BP by 1.6 mm Hg and mean arterial BP by 1.2 mm Hg (Po0.05), independent of exercise. Regular exercise increased fat oxidation during exercise by 0.10 g min À1 (Po0.01) and reduced abdominal fat by 0.92% (Po0.05). Conclusion: Although HF consumption was shown to improve endothelial function, it did not enhance the effects of exercise on body fat and fat metabolism in obese subjects. However, it may be useful for reducing cardiometabolic risk factors in this population.

Considering the relationship between VO2max and various markers of health, the use of step tests as a measure of health in both the general adult population and rehabilitation settings is advocated. Step tests provide a simple, effective and ecologically valid method of submaximally assessing VO2max that can be implemented in a variety of situations within the general adult population. Future research is needed to assess the reliability of the majority of the step-test procedures reviewed. Based on the validity measures, submaximal step-test protocols are an acceptable means of estimating VO2max in the generally healthy adult population. For tracking changes in cardiorespiratory fitness, the Chester Step test appears to be an appropriate tool due to its high test-retest reliability.

CRD42015020194.