Despite all the talk about concussions in pro football and sports injuries generally, the fact is that more professional athletes are playing longer. In 1982 there were 14 players over 35 in the NFL; now there are 40. In the NBA that number went from 2 to 20, and in the NHL from 4 to 56 over age 35 playing now. They do it by paying meticulous attention to their bodies; hitting the weights in the off-season, being very careful about what they eat, and going through elaborate recovery routines. And just about everything they do can be adopted by aging amateurs who are willing to work at staying fit.