A Motherboard.com article pointed out reflexes are one of the first things to decline at an early age, with this sobering quote: "At the Red Bull Battlegrounds tournament in New York, I met a player, Golden, who was retiring at the ripe old age of 19. The most successful non-Korean player, Stephano, retired last year at 20."
The reason comes from researchers in British Colombia illustrating their finding of professional Star Craft 2 players with this dramatic chart showing reaction times at all skill categories slow down after 24:
With the Miami Heat's best player, Dwyane Wade at 33 years old, their max player Chris Bosh at 31, starting forward Luol Deng at 30, key point guard Goran Dragic 29, and center Hassan Whiteside at 26, the roster playing style needs to adapt to winning with their brains and skills instead of their quickness.