In a Race Against Time.(mature athletes training in record numbers)(fitness routine standards)

Ching Teng soon started lifting weights in his teens and for a decade competed on the amateur body-building circuit in Singapore. Then came marriage, three kids and a day job as a clerk for a trading company, which meant putting aside his dumbbells and letting his body soften into old age. Two years ago, at 67, he decided to get back into the fray. The Asian games were nearing, and he wanted to try out for Singapore's body-building team. He hit the gym six times a week for three hours at a pop, not including an hour of stretching and push-ups. After four months, he realized he wasn't going to make it. "I tried to catch up, but it was too tough to compete against young people," he says. But Ching still wants to lift weights "for as long as I can," he says. "This is part of my life."

Ching and hundreds of thousands of maturing athletes like him are launching a quiet revolution in the world of sports. At an age when their own grandparents were heading for the rocking chair, these over-50s are taking to the pools, the gyms and the courts in record numbers. It's not that these late-life athletes are ever going to relive their glory days. The finest 60-year-old tennis player can't pretend to have the strength and easy agility he did at 20. But a growing number of them are discovering firsthand what doctors have said for years: exercise keeps you young. Over-50s are eager to reap the health benefits--a stronger heart, improved posture, sharper mental acuity, less depression and lower rates of diabetes, high blood pressure and cancer. And they're remaking both their sports and their attitudes to do it.

The key to healthy aging is finding a fitness routine that can last a lifetime. "You don't drive a vintage car the way you would a new race car," says Dr. Nicholas DiNubile, spokesman for the American Orthopedic Society for Sports Medicine. "You have a different body than you had in your 30s. It's going to need kinder, gentler handling." Older athletes often switch from high-impact sports to lower-impact ones like biking, swimming and walking. They also take up cross-training to improve cardio fitness, flexibility and strength. All the while, they're weaving a network of active, optimistic fellow travelers-- competitors, coaches, mentors ...