|
STAYING A STEP AHEAD OF AGING
By Gina Kolata
Published: January 31, 2008
New York Times
YOU know what is supposed to happen when you grow old. You will slow down, you will grow weak, your steps will become short and mincing, and you will lose your sense of balance. That’s what aging researchers consistently find, and it’s no surprise to most of us.
But it is worth remembering that the people in those studies were sedentary, said Dr. Vonda Wright, a professor of orthopedics at the University of Pittsburgh.
Dr. Wright, a 40-year-old runner, decided to study people who kept training as they got older or began competing in middle age. She wanted to know what happens to them and at what age does performance start to decline.
Their results are surprising, even to many of the researchers themselves. The investigators find that while you will slow down as you age, you may be able to stave off more of the deterioration than you thought. Researchers also report that people can start later in life — one man took up running at 62 and ran his first marathon, a year later, in 3 hours 25 minutes.
It’s a testament to how adaptable the human body is, researchers said, that people can start serious training at an older age and become highly competitive. It also is testament to their findings that some physiological factors needed for a good performance are not much affected by age.
Researchers say that you should be able to maintain your muscles as you age, including the muscle enzymes needed for good athletic performance, and you should be able to maintain your ability to exercise for long periods near your so-called lactic threshold, meaning you are near maximum effort.
But you have to know how to train, doing the right sort of exercise, and you must keep it up.
“Train hard and train often,” said Hirofumi Tanaka, a 41-year-old soccer player and exercise physiologist at the University of Texas.
Dr. Tanaka said he means doing things like regular interval training, repeatedly going all out, easing up, then going all out again. These workouts train your body to increase its oxygen consumption by allowing you to maintain an intense effort.
“One of the major determinants of endurance performance is oxygen consumption,” Dr. Tanaka said. “You have to make training as intense as you can.”
When you have to choose between hard and often, choose hard, said Steven Hawkins, an exercise physiologist at the University of Southern California.
“High performance is really determined more by intensity than volume,” he added. “Sometimes, when you’re older, something has to give. You can’t have both so you have to cut back on the volume. You need more rest days.”
Dr. Hawkins, who says he no longer runs competitively, adds that he tries to put his findings into practice. “I run a couple of times a week and I try to make it as fast as I can,” he said. “I’m not plodding along.”
He also has been amazed by some people who seem to defy the rules of aging, people he describes as “those rare birds who get faster.” Some subjects in Dr. Hawkins’s research study, which followed runners for nearly two decades, actually had better times when they were 60 than when they were 50.
“We really don’t know why,” Dr. Hawkins confessed. “Maybe they were training harder.”
Then there are people like the 62-year-old man who suddenly took up running and began running fast marathons. That man’s inspiration to become a runner, said James Hagberg, an exercise physiologist at the University of Maryland, was watching a lakefront marathon in Milwaukee. “He got all fired up,” Dr. Hagberg recalled.
And there are people like Imme Dyson, a 71-year-old runner who lives in Princeton, N.J. She took up running when she was 48 and loved it, she says, from the moment she put on a pair of running shoes. Her daughter, who had been a college triathlete, told her how to train.
“She said, ‘Mom, if your workout didn’t hurt, you didn’t work hard enough,’ ” Ms. Dyson said.
“Working consistently really is the recipe,” she said. And it has made a difference for her, allowing her to run races, from 5K to marathons, so fast that she is consistently among the best in the nation in her age group. She has run a 15K cross-country race in 1:19:08, a pace of 8:29 a mile. And she ran a 10K race in 51 minutes 50 seconds, a pace of 8:20 a mile.
Not every aging athlete does so well. But Dr. Hagberg found that studies of aging athletes sometimes were distorted because they included people who had cut back on or stopped training. That’s understandable; there is no reason, researchers say, to exhort everyone to maintain an intense effort decade after decade.
Athletes would tell Dr. Hagberg that they had just lost their motivation. “Some of them would say: ‘Competition just doesn’t motivate me as much at 75. I’ve been doing it for 50 years,’ ” he said. “Others would say, ‘I just can’t keep it up any more.’ ”
But for those who still have the drive, the news that muscle mass and lactic threshold can be maintained is encouraging.
The reason people become slower, though, is that oxygen consumption declines with age.
In large part that is because, as has long been known, the maximum heart rate steadily falls by about seven to eight beats per minute per decade. It happens with or without training, in sedentary and in active people, Dr. Tanaka said, and no one knows why. But as a result, the heart cannot pump as much blood at maximum effort.
Dr. Michael Joyner, a 49-year-old exercise researcher at the Mayo Clinic who also is a competitive swimmer and a runner, added another factor: the lungs of older athletes cannot take in quite as much air.
With a slower heart rate and less oxygen in the lungs, less oxygen-rich blood gets to the muscles. In one study, Dr. Joyner found that highly trained athletes age 55 to 68 had 10 to 20 percent less blood flow to their legs than athletes in their 20s.
The older athletes in his group, though, were edging toward an age that often is a transition time in athletic performances, researchers are finding. For example, Dr. Wright and her colleague Dr. Brett Perricelli found that the performances of track athletes declined almost imperceptibly from year to year until their mid-60s, when the rate of decline picked up. At age 75, though, the athletes’ times fell, on average, by 7 percent.
The study, the results of which will appear in the March issue of the American Journal of Sports Medicine, involved track and field athletes age 50 to 85 who were participants in the 2001 Senior Olympics and also examined the times for American record holders in track events.
But older athletes still can have spectacular performances, Dr. Tanaka notes.
For example, the world best marathon time for men 70 or older (2:54:05) was set by a 74-year-old. That is more than four minutes faster than the winning marathon time at the first modern Olympics, the 1896 Games in Athens.
Of course, such statistics are of little comfort to athletes who do not want to slow down at all. Dr. Hawkins said he and Robert A. Wiswell, the senior author on his nearly 20-year study of athletes, used to joke that they needed a sports psychologist rather than a sports physiologist on their study. The athletes, he explained, could not bear to think that they would stop setting personal records.
That’s an issue for Don Truex, a 70-year-old dentist in Santa Barbara, Calif, who can’t understand why he has slowed down in the last year. He just ran a 5K race in 23:45. It was an average pace of 7:38 a mile, 90 seconds slower than he wanted to run.
“I’ve consulted with my doctor and we think I may be overtraining,” Dr. Truex said. He’s going to continue running five days a week but cut back on his five days a week of cycling.
Slower times are even more of a concern for Dr. Truex’s friend Barry Erbsen, a 67-year-old dentist in Los Angeles.
Dr. Erbsen started running seriously around 40. His best time in a 10K race was 38 minutes, a pace of 6 minutes a mile. Next he started running marathons, going faster each time until he had completed several, including the Boston Marathon, in 3:07:00.
Then, Dr. Erbsen started to slow down. He ran a marathon a few years ago in 3:45:00. He completed his next one in 3:58:00.
That nearly four-hour marathon was his last, he said. Instead, Dr. Erbsen took up mountain biking. So far so good, he said. He’s having a lot of fun. And, he added, “I’m not getting too much slower.”
|
