The effect of water-based rhythmic exercise training on glucose homeostasis and thyroid hormones in postmenopausal women with metabolic syndrome

Objectives The present study aimed to explore the effect of water-based rhythmic exercise training on fasting blood sugar (FBS), homeostatic model assessment (HOMA), insulin, thyroid stimulating hormone (TSH), and T4 in postmenopausal women with metabolic syndrome. Methods In this clinical trial, 31 postmenopausal woman with metabolic syndrome aged 69.16 ± 2.02 years were randomly assigned to an experimental (n=16) and a control group (n=15). The training program was composed of 12 weeks of water-based rhythmic exercise training performed intermittently for 60 min three times a week. Before and after training, blood was analyzed for glucose homeostasis, T4, and TSH. Data were subjected to analysis by paired t-test and covariance analysis at the p<0.05 level. Results The exercise training intervention reduced the FBS and insulin significantly (p=0.000). The growth hormone (GH) index was increased significantly only in the experimental group (p=0.037) whereas no significant variations occurred in the insulin-like growth factor-1 (p=0.712). It was also found that TSH and T4 change in the experimental group as compared to the pre-test. Conclusions Water-based rhythmic exercise training may improve blood glucose homeostasis, TSH, and T4.

Predicting Blood Flow Responses to Rhythmic Handgrip Exercise From One Second Isometric Contractions

The aim of this work was to predict blood flow responses to rhythmic handgrip exercise from one second isometric contractions. Seven healthy men were studied. Each subject performed a single 1 s handgrip contraction at 10 %, 20 % and 40 % of the maximum handgrip strength. We then repeatedly summed hyperaemic responses from single contractions to predict hyperaemic response to a prolonged bout of rhythmic exercise. There was similarity between steady state brachial blood flow velocity (BBV) extrapolated from single handgrip contractions and during 2 min of rhythmic exercise for 20 % (10.0±3.8 cm/s vs. 10.2±2.6 cm/s, r=0.93, p=0.003) and 40 % of maximum contractions (14.2±5.5 cm/s vs. 15.6±3.4 cm/s, r=0.88, p=0.009), but not for 10 % (7.5±4.1 cm/s vs. 5.7±3.3 cm/s, r=0.94, p=0.018). BBV progressively rose substantially higher during rhythmic contractions than peak BBV observed during single contractions at matched intensity. Respective peak BBV during single contractions and steady state BBV rhythmic contractions were 4.4±2.1 and 5.7±3.3 cm.s−1 at 10 % forearm strength (p=0.14), 5.6±2.4 and 10.2±2.8 cm.s−1 at 20 % (p=0.002), and 7.0±2.5 and 15.6±3.6 cm.s−1 at 40 % (p=0.003). In conclusion, there is similarity between the summated blood flow velocity calculated from a single 1 s muscle contraction and the steady state blood flow velocity response of rhythmic exercise.