Shouldn't we just send athletes to the military after they retire?

‌Literally, they would just be performing a role
People would probably argue that their bodies are already damaged from training and so on
But would Park Tae-hwan's stamina really be worse at 35 than it was at 20??
Even if you sent a 35-year-old retired Park Tae-hwan to serve in the UDT, he would perform much better
Even if Son Heung-min went to the military right now, he would run better than someone in their 20s
If they are athletes, even at the point of retirement, they would easily overpower a regular 20-year-old who has no athletic background
For shooting athletes, we could just have them serve as snipers through special promotion tracks