Celecoxib Alters Markers of Muscle Remodeling without Affecting Exercise Performance in Rats

Introduction Celecoxib (CELE) is widely prescribed to manage pain and inflammation in both clinical and physically active populations. Its use is particularly common among athletes, aging adults, and military personnel who regularly engage in structured exercise or rehabilitation programs. This study examined the effects of 6 wk of treadmill running, with or without CELE administration, on skeletal muscle outcomes in young healthy male rodents. Methods Nine-week-old male Wistar rats were randomized into control or exercise groups and treated with either CELE (19 mg·kg −1 ·d −1 ) or 1% dimethylsulfoxide. Treadmill exercise was performed 5 d·wk −1 for 6 wk at moderate intensity. Body weight, food intake, and water intake were measured. Maximal exercise performance was assessed in week 6. At the end of week 6, skeletal muscles were collected for analysis of fiber-type composition, cross-sectional area, myosin heavy-chain expression, and protein signaling. Results Combining CELE with 6 wk of exercise reduced myosin heavy-chain messenger ribonucleic acid expression, increased protein kinase B phosphorylation, and activated pathways associated with muscle atrophy in the quadriceps. In the soleus muscle, this was accompanied by lower myosin heavy-chain protein levels and a decreased proportion of type II fibers. However, there were no detectable changes in exercise performance. Conclusion Chronic CELE altered molecular markers of muscle remodeling in both exercised and sedentary rats but did not affect treadmill performance. These results suggest that CELE may influence muscle metabolism without impairing overall adaptation. Further studies are needed to assess whether higher doses, longer durations, or more intense training modify these effects.