Agassi continues to be a major force in the men 's game despite his advancing years . The Swiss champion heads a rankings list with 24 players over 30 in the top 24 . So you have to counter that and prepare your body for the game , '' Reyes said . Agassi fitness coach Roger Federer says modern game takes great toll on body . Strength was a key factor in Roger Federer 's longevity allowing him to play with `` great relevance '' up until age of 36 .
Agassi continues to be a major force in the men 's game despite his advancing years . The Swiss champion heads a rankings list with 24 players over 30 in the top 24 . Agassi fitness coach Roger Federer says modern game takes great toll on body . Strength was a key factor in Roger Federer 's longevity allowing him to play with `` great relevance '' up until age of 36 .