For years, coaches have devised training plans that presume we all need more downtime between intense workouts as we age. But while older athletes do face physiological limitations of —a lower VO2max, for one—many guys in their forties and fifties can bounce back from a hard day just as quickly and completely as young guns with full heads of hair. Jim Rutberg, of Carmichael Training Systems, says this is because age is just one determinant of physical capacity, and it’s frequently offset by lifestyle habits like earlier bedtimes, smarter nutrition, and fewer Red Bull–and–vodkas. “Older athletes tend to be more stable and less stressed,” he says. “When it comes to performance, age is less a factor than what’s going on in the rest of your life.”