Exercise training dose differentially alters muscle and heart capillary density and metabolic functions in an obese rat with metabolic syndrome

Abstract

What is the central question of this study? Regular exercise is recommended as a non-pharmacological approach for the prevention and treatment of metabolic syndrome. However, the impact of different combinations of intensity, duration and frequency of exercise on metabolic syndrome and microvascular density has not been reported. What is the main finding and its importance? We provide evidence on the impact of aerobic exercise dose on metabolic and microvascular alterations in an experimental model of metabolic syndrome induced by high-fat diet. We found that the exercise frequency and duration were the main factors affecting anthropometric and metabolic parameters and microvascular density in the skeletal muscle. Exercise intensity was related only to microvascular density in the heart. We evaluated the effect of the frequency, duration and intensity of exercise training on metabolic parameters and structural capillary density in obese rats with metabolic syndrome. Wistar-Kyoto rats were fed either a standard commercial diet (CON) or a high-fat diet (HFD). Animals that received the HFD were randomly separated into either a sedentary (SED) group or eight different exercise groups that varied according to the frequency, duration and intensity of training. After 12 weeks of aerobic exercise training, the body composition, aerobic capacity, haemodynamic variables, metabolic parameters and capillary density in the heart and skeletal muscle were evaluated. All the exercise training groups showed reduced resting systolic blood pressure and heart rate and normalized fasting glucose. The minimal amount of exercise (90 min per week) produced little effect on metabolic syndrome parameters. A moderate amount of exercise (150 min per week) was required to reduce body weight and improve capillary density. However, only the high amount of exercise (300 min per week) significantly reduced the amount of body fat depots. The three-way ANOVA showed a main effect of exercise frequency and duration for the improvement of metabolic syndrome and capillary density in skeletal muscle. Exercise intensity was a main factor in reversing microvascular rarefaction in the heart.

Physical exercise promotes astrocyte coverage of microvessels in a model of chronic cerebral hypoperfusion

“…This was reported by Farkas and colleagues who described a 10 to 20 mmHg increase in systolic blood pressure at 24 h after 2VO, persisting for up to 9 weeks [4]. Physical training, particularly aerobic exercise, has been shown to be an effective non-pharmacological therapeutic approach in the reduction of blood pressure in models of metabolic syndrome [35] and hypertension [36]. A normalization in systolic blood pressure was observed in our 2VO model after 12 weeks of moderate exercise compared to animals that were sedentary for this period.…”

Early life stress reduces voluntary exercise and its prevention of diet-induced obesity and metabolic dysfunction in mice

“…In humans, environmental factors including early life stress [3][4][5], poor diet [16,17], and low activity level [34][35][36] increase one's risk to develop the MetS. Many pre-clinical studies have investigated the influence that HFS diet [37][38][39][40] and exercise [31,41,42] have on the development of obesityrelated MetS, while only a few have investigated the impact of early life stress [14,15]. To our knowledge, this is the first study to combine early life stress, exercise, and diet to evaluate outcomes related to this disorder.…”

The effect of varied exercise intensity on antioxidant function, and aortic endothelial cell function and serum lipids in a non-alcoholic fatty liver disease rats

“…Exercise plays an important role in improving lipid metabolism disorders, and is increasingly seen as an adjunctive therapy for the prevention and treatment of NAFLD (16, 17, 42). Machado MV et al showed that exercise intensity would be more effective in improving metabolic parameters than frequency or duration (43). A retrospective study indicated that moderate and vigorous intensity physical activity yielded similar health benefits to low, in terms of the measured body adiposity and serum TG (38).…”