Looking to bring my domestic cat into Olympic trails? What to feed the athlete?

Right now I train him but looking for a good diet. I have been mixing tuna into the purina one for muscle m and health. Was wondering if anyone new of any other good things to feed a domestic shorthair who is a born athlete. Want to put him in the american domestic feline olympic trails for the 100 meter sprint. I feel like he is ready. Any other training advice?