Effects of swimming and running exercise trainings on the structure of the muscles, bone and oxidative stress in rats

This study investigated the effects of swimming and running exercises on muscle, bone structure and oxidative stress in 18 male rats 16 months old. The rats were divided into control, swimming, and running groups, with six rats each. the exercise groups underwent eight weeks of moderate-intensity swimming or running. Analyses were performed based on the post-test measurements. Post-test measurements included blood total oxidant (TOS) and antioxidant status (TAS) and oxidative stress index (OSI); gastrocnemius muscle fiber type, and femur bone morphometric measurements. While OSI was higher in both exercises' groups, it was not statistically different from the control group (p>0.05). The ratio of type I fibers in the exercise groups was similar (p>0.05); however, it was higher than the control group (p<0.05). The type IIa fiber ratio was different between the groups, with the highest in the control group and the lowest in the running group (p<0.05). Bone surface area, trabecular thickness, cortical thickness, and total bone thickness were significantly higher in the running group than in the control group (p<0,05), while there was no difference between the exercise groups (p>0,05). In addition, distal femur bone area and trabecular width measurements were higher in the swimming group than the control group (p<0.05). In conclusion, running and swimming exercises induces similar changes in muscle fiber compositions by increasing slow-twitch fiber proportion. Overall, running exercises had a greater impact on bone structure, while swimming had a limited effect. Both exercises increased oxidant and antioxidant capacity and oxidative stress in aged male rats.