Skeletal muscle produces GDNF, which is a neurotrophic factor that is critical for the development and maintenance of neural tissue. GNDF is a potent survival factor that can rescue motor neurons from programmed and axotomy induced cell death. The present study investigated the relationship between exercise and GDNF expression in skeletal muscle comparing 11 and 17 week old (n=6) Fischer 344 rats. The 11 week old animals were exercised for 2 weeks, half of the group was euthanized immediately after exercise and the remaining were euthanized 24 hours later. The extensor hallucis longus (EHL) muscle was removed and analyzed for GDNF content using enzyme‐linked immunosorbant assay (ELISA). GDNF content was significantly higher in animals that were exercised and euthanized 24 hours later compared to age matched sedentary controls (n=6). Immunohistochemical staining for skeletal slow muscle fiber and GDNF suggested an increase in GDNF content in the slow fibers. Labeled α‐bungarotoxin localized GDNF to the motor end plates in the skeletal muscle. Animals euthanized immediately after exercise showed a decrease in frequency of end plates staining positively for GDNF compared to controls. These results suggest physical activity modulates GDNF expression in skeletal muscle. This work was supported by NIH Grant 1R15AG022908‐01A2, MSU‐KCMS, and Western Michigan University.