We have examples of multiple wrestlers coming into MMA later in life and having success into their 40s.
- Couture started MMA at 34
- Coleman started MMA at 32
- Cormier started MMA at 30
- Hendo started MMA at 28
Clearly the rigors of wrestling don't effect your shelf life that bad in terms of fighting. All of these guys found success in MMA in their 40s.
On the flip side, fighters that started their MMA early rarely make it to the age of 40 and still find success at that age. Vitor, Anderson, and in a few years Overeem, all had much longer careers than the guys I mentioned above but by the time they hit 40 their success came to screeching halt. The reason for that is competing in MMA shortens your shelf life faster than wrestling does.... We have almost 25 years to extrapolate that data.