Endocrine Abstracts

Obesity is a chronic multifactorial disease characterized by accumulation of body fat and is associated with a number of comorbidities, such as diabetes and cardiovascular disease. The treatment of obesity depends to the severity of the disease, however, healthy eating with caloric restriction and physical activity are important strategies. In the present study, we aimed to evaluate the effect of obesity associated with strength training on skeletal muscle morphology, body adiposity and metabolic parameters in a rodent model. 58 male Wistar rats were randomized into two groups: control, fed standard diet (C), and obese, fed a high fat diet (49.2% fat) (Ob). The experimental protocol consisted of 28 weeks, being divided into three moments: M1) induction to obesity; M2) maintenance of obesity and; M3) strength training protocol. After the maintenance of obesity period, animals were randomized into two new groups. Thus, the study was finally composed of four groups: sedentary control (CS), control submitted to the strength training protocol (CT), obese sedentary (ObS) and obese submitted to strength training protocol (ObT). Strength training was performed on a ladder 3 times a week for 10 weeks. High-fat diet was efficient to induce animals to obesity in the second week of the experimental protocol, initiating the period of exposure to obesity. Training protocol did not result in hypertrophy of soleus, tibialis, plantar and FHL skeletal muscles, as neither wet and dry muscle weight nor fiber cross-sectional areas were different among groups. The training protocol used was efficient to increase absolute strength, but the capacity to produce strength seems to be impaired in obesity when relative strength was evaluated. Body weight gain was lower in the groups submitted to strength training compared to sedentary groups (ObT vs ObS, CTF vs CS). High-fat diet-induced obesity resulted at higher body adiposity and blood leptin levels but this was attenuated by training. ObT group presented lower total body fat, adiposity index and blood leptin levels compared to ObS group. ObS blood triglycerides were higher compared to CS and CT, but training reversed this effect in ObT group. Blood total cholesterol and HDL were not different among groups. Therefore, the strength training in obese rats promoted metabolic adaptations and reduction in adiposity even in the absence of muscle hypertrophy.