What he is trying to say is that playing computer games isnt as heavy on the body as running sprints at old age. So your claim that is IMPOSSIBLE for him to do this is rather invalid. If anything should be a problem when gaming it is the responsetime of a older player vs. a younger one. but that is still not relevant untill f0rest gets 40+ so, he got 10 more years to own.
+ with age comes experience, and if you been competing for this long, he surely is alot more calm in pressured situations (like majors, which young players, who hasnt experienced that sence easly can crumble). So I really do not agree with this whole "age" theory.