Lee Walton, 69, was huffing, his wavy hair flying, as he rounded the bend at the high school track with quick strides of his lean legs. The teenage girls jogging for a physical education class appeared to be moving in slow motion as he whizzed past.

This was no race for Walton, a retired metallurgical engineer. It was just a training session for the Senior Olympics.

While not as obsessive as some runners, Walton, who lives in Pittsburgh, spent the spring alternating each day between long-distance and sprint-oriented training. He also walks three miles a day with his wife, uses free weights at home and occasionally visits a gym. His 155 pounds of weight is one less than when he signed up for the Naval Reserves after high school.

And yet, with an overall level of fitness most people his age and even younger only fantasize about, Walton is just as mortal as nearly everyone else past their 20s in one regard: He keeps slowing down.

There are a few aberrant spikes over the years, when a particular track condition or a close competitor brought out the best in him, but his handmade chart of the past decade’s performance times shows a couple seconds of slowdown most years.

“Everyone has their limits and, as you grow older, obviously your muscles change,” Walton said. “It also becomes more of a disciplinary challenge to train and run, because it becomes easier to procrastinate and put it off. Your injury rate increases, and your ability to recover from injury takes longer.”

Lee Walton, 69, of Unity, Pa., has won various national and state medals in the Senior Olympics. Despite a fitness level that most 20-year-olds admire, Walton's running pace has slowed. Doctors say the effects of aging can't be overcome, no matter how hard one tries.

The worst is yet to come, according to a University of Pittsburgh research team that examined performances of senior athletes.

Sharp decline at 75

The study found moderate decline in performance among athletes in their 50s and 60s, and then a steep decline starting at 75. The study headed by Dr. Vonda Wright, a clinical instructor in the University of Pittsburgh’s Department of Orthopedics, suggested the effects of muscle weakening, cardiovascular capacity decline and diminished bone mineral density can’t be overcome, no matter how hard one tries.

“Even the best of the best of us experience a substantial decline after 75,” said Wright, whose report called that age “a tipping point” for plummeting athletic abilities.

The study focused on Senior Olympians whose performances could be measured – in track events, especially – as opposed to competitors in basketball, badminton and other endeavors with imprecise evaluation methods. Senior Olympians compete in five-year age brackets starting at age 50, and the study compared the average of the top eight male scores and top eight female scores in each age group.

So rather than measuring the slowdown of individual athletes over time, Wright analyzed how much slower each succeeding five-year age group was than the younger group ahead of it.

In Walton’s best event, the 1500 meters, in which he won gold in the national games in 2001 for ages 65-69, he was 23 seconds slower than the top finisher among those 60-64. In the 70-74 group, the gold medal winner was 42 seconds slower than Walton. And the fastest man 75 or older was 2 minutes, 8 seconds slower than that.

Wright’s study found similar patterns for both women and men.

Exercise still benefits

That doesn’t mean the older athletes have any reason to lack motivation.

“It is important to remember that when we discuss declines in performance that these are relative to their amazing baseline performances,” Wright said. “A 75-year-old senior athlete with a performance decline is still many times faster and in better health than a sedentary 30- or 40-year-old.”

Miriam Nelson, director of the John Hancock Center for Physical Activity at Tufts University, noted that the maximum heart rate in high-intensity exercise peaks at age 20, making it harder every year thereafter for anyone to maintain their performance unless they intensify their conditioning.

“I think the muscle strength and cardiovascular fitness eventually becomes a real limiting factor, no matter what your technique,” she said. “I bet some chronic diseases like arthritis and osteoarthritis start to play a role then in reducing physical capacity.”

Rod Brown, 78, a St. George, Utah, resident who won golds in the 200, 400 and 800 meters at the 2003 Senior Olympics in Hampton Roads, Va., said he was able in his 60s to defy the norm and gradually improve times in senior competition by working on conditioning, diet and technique. That came after a 40-year layoff from running. His best times came in 1999.

“The other guys said, ‘Hey, what’s going on here? We’re all getting slower and you’re getting faster,'” Brown recalled.

The retired dentist alternates days of running on a track and running up hills on a golf course, plus does weight lifting and runs on treadmills in a gym, but he’s no longer counting on any of that to maintain his performance level.

“Now, judging by the past five years or so, it looks like a slow decline,” he said.

“Looking at times for the age groups, you can see a little less for each five years. I’d like to think I’ve got a little edge on most other people, but at the same time, I can see decline happening.”