Effect of strength training on morphology of skeletal muscle of obese rats
Name: CATARINA DENISE ENTRINGER CONTREIRO
Publication date: 21/12/2017
Advisor:
Name |
Role |
|---|---|
| LUCAS GUIMARÃES FERREIRA | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| ANA PAULA LIMA LEOPOLDO | Internal Examiner * |
| ANDRÉ SOARES LEOPOLDO | Internal Alternate * |
| LUCAS GUIMARÃES FERREIRA | Advisor * |
| RICHARD DIEGO LEITE | External Alternate * |
Summary: Obesity is a chronic multifactorial disease characterized by accumulation of fat in the body, causing damage to the health of the individual. The treatment of obesity varies according to the severity of the disease, however, healthy eating with caloric restriction and physical activity are strategies used in this process. The beneficial effects of regular physical activity are related to adaptations that occur in various organs of the body, including skeletal muscle. The effects of obesity on skeletal muscle hypertrophy induced by strength training are not well understood. Clarifying the interaction mechanisms is fundamental for the development of new approaches in the treatment of obesity. The objective of the present study was to evaluate the effect of obesity associated with strength training on skeletal muscle morphology. For this, 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, the animals were randomized into two new groups. Thus, the study was composed of four groups: sedentary control (CS), control submitted to the strength training protocol (CTF), obese sedentary (ObS) and obese submitted to strength training protocol (ObTF). Strength training was performed on a mouse ladder 3 times a week for 10 weeks. The hyperlipid diet was efficient to induce animals to obesity in the second week of the experimental protocol, initiating the period of exposure to obesity. The weight of the soleus, tibial and FHL muscles were higher in the ObTF group compared to the CTF group, however the training protocol did not promote hypertrophy in the cross-sectional area of the FHL and plantar muscles. The training protocol used was efficient to increase the absolute strength in the trained groups, but the capacity to produce strength seems to be impaired in obesity when relative strength was evaluated. At the beginning of the training, the ObTF group already had lower relative strength compared to the ObTF group, this difference was maintained after the training protocol. The training was efficient to promote positive changes in body weight and accumulation of fat in trained animals. Body weight gain was lower in the groups submitted to strength training compared to sedentary groups (ObTF vs ObS, CTF vs CS). The ObTF group presented lower total body fat and adiposity index in relation to the ObS group.
