1.
Time course of endothelial adaptation after acute and chronic exercise in patients with metabolic syndrome.
Tjønna, AE, Rognmo, Ø, Bye, A, Stølen, TO, Wisløff, U
Journal of strength and conditioning research. 2011;(9):2552-8
Abstract
Clustering of cardiovascular risk factors may lead to endothelial dysfunction. Physical exercise is an important factor in prevention and treatment of endothelial dysfunction. We wanted to determine the time course of adaptation to a single bout of exercise at either high or moderate intensity upon endothelial function both before and after a 16-week fitness program in patients with metabolic syndrome. Twenty-eight patients with metabolic syndrome participated in the study and were randomized and stratified (according to age and sex) into an aerobic interval exercise training group (AIT, n = 11), a continuously moderate-intensity exercise training group (CME, n = 8) or to a control group (n = 9). Flow-mediated dilatation (FMD) was determined at baseline, immediately, 24, 48, and 72 hours after 1 bout of exercise and repeated after 16 weeks of exercise. In the untrained state, FMD improved from 5 to 11% (p = 0.003) immediately after a single bout of aerobic interval training (AIT), an effect lasting 72 hours postexercise. In comparison, continuous moderate exercise (CME) improved FMD immediately after a single bout of exercise from 5 to 8% (p = 0.02), an effect lasting 24 hours postexercise (group difference, p < 0.001). In the trained state, a single bout of AIT resulted in a 2% (p = 0.007) acute increase of FMD lasting 48 hours postexercise. The CME increased FMD by 3% (p < 0.01), an effect lasting 24 hours postexercise (group difference p = 0.0012). Blood glucose level decreased after 1 single bout of AIT in the untrained state (p < 0.05), and the effect lasted at least 72 hours postexercise (p < 0.01). Acute CME decreased blood glucose with normalization of the values 24 hours postexercise (p < 0.01). A single bout of exercise in the trained state reduced fasting blood glucose by 10% (p < 0.05) after both AIT and CME. Exercise training, especially high intensity, thus appears to be highly beneficial in reducing blood glucose and improving endothelial function.
2.
Dose Response to Exercise in Women aged 45-75 yr (DREW): design and rationale.
Morss, GM, Jordan, AN, Skinner, JS, Dunn, AL, Church, TS, Earnest, CP, Kampert, JB, Jurca, R, Blair, SN
Medicine and science in sports and exercise. 2004;(2):336-44
Abstract
INTRODUCTION AND PURPOSE Physical inactivity in postmenopausal women contributes to a rise in atherogenic risk factors associated with the metabolic syndrome. Although regular physical activity positively contributes to health, inactivity progressively increases with age. The Dose Response to Exercise in Women aged 45-75 yr (DREW) study is designed to investigate the effect of different amounts of exercise training on cardiorespiratory fitness and risk factors for cardiovascular disease (CVD) in postmenopausal women at moderately increased risk of CVD. METHODS DREW will recruit 450 sedentary, healthy, postmenopausal women with a body mass index of 25-40 kg.m-2, resting systolic blood pressure (BP) of 120-159 mm Hg, and a resting diastolic BP of < or = 99 mm Hg. Laboratory and self-report measures completed at baseline and 6 months include maximal oxygen consumption (.VO2max), resting BP, anthropometry, dietary habits, physical activity history, medication use, menstrual history, personal and family medical history, and fasting HDL cholesterol, LDL cholesterol, triglycerides, and glucose. Eligible participants are randomly assigned to a nonexercise group or one of three exercise groups. Participants exercise 3 to 4x wk-1 at a heart rate equivalent to 50% of .VO2max expending 4, 8, or 12 kcal.kg-1.wk-1, depending on group assignment. This study will allow quantification of possible dose-response relations (50%, 100%, and 150% of the consensus physical activity recommendation) between exercise training and study outcomes. CONCLUSION DREW can make important contributions to our understanding of the effects of physical activity in postmenopausal women and help refine public health and clinical recommendations for this group.