The aim of the present study was to determine the modeling of muscle fibers in rats submitted to different exercise protocols. Fifty-five Wistar rats were submitted divided into four different groups: Control group (CG; N=16); endurance training group (ETG; N=13), strength training group (STG; N=13) and concurrent training group (CTG; N=13). The intensity of endurance training was determined by the critical workload. Statistical analysis involved the Kruskal-Wallis test for multiple comparisons, followed by Dunn's post test (p<0.05). All animals submitted to training exhibited an increase in the cross-sectional area of the muscle fibers. The largest increase (p>0.05) occurred in the STG and CTG at both four (mean:2952,95 ± 878,39 mean:2988,84 ± 822,58) and eight weeks respectively (mean:3020,26 ± 800.91; mean:3104,91 ± 817,87). The findings demonstrate similar results obtained with strength training and concurrent training, with a greater increase in muscle fiber area in both groups in comparison to the control group and group submitted to endurance training.
skeletal muscle; soleus muscle; concurrent training; aerobic exercise; anaerobic exercise
