Background: Individuals with cerebral palsy (CP) are prone to sedentary life with limited recreational- and physical activity. RaceRunning (RR) is a sport for individuals with disabilities such as motor impairment that allow them to move independently and enjoy physical activity. The aim of the study was to investigate muscle fatigue of RR athletes with different classiffcation of CP during six minuteRaceRunning test (6MRRT). The Cerebral Palsy International Sports and RecreationAssociation has the goal to make RR a Paralympic sport. For a sport to be included in the Paralympics a classiffcation system has to be made. Information about muscle function during RR could give vital physical information about athletes with CP and contribute to the development of such classiffcation system. Method: Median frequency of the power spectrum from surface electromyography(sEMG) of four muscles (vastus lateralis, biceps femoris, gluteus medius, gastrocnemius lateralis) was computed along with amplitude changes (root mean square) in order to assess muscle fatigue. Results: Indications of muscle fatigue were observed from one out of five athletes for athlete's less affected side. Further sEMG studies with more subjects have to be conducted on CP RR athletes to give more conclusive results of muscle fatigue.