Posts Tagged "muscles"

Young runners are different than you and me. They have more speed. And to achieve that swiftness, they use certain leg muscles quite differently than runners past age 50 do, according to a new study of runners’ strides at different ages. The study also says that many of us might be able to reinvigorate our flagging pace with the right type of strength training.

Competitive records and lived experience all show that runners slow with advancing age, even the great ones. The current world marathon record for men, for instance, 2:02:57, was blazed by a 30-year-old, and is nearly an hour faster than the world record of 2:54:48 for the 70- to 75-year-old age group, which was set by Ed Whitlock, a Canadian. He later ran the world record for the 80- to 85-year-old age group with a 3:15:54 clocking that, although blisteringly fast by my standards, was more than 20 minutes slower than his septuagenarian self.

While most of us accept this diminution in speed as inevitable and logical — we’re older, of course we’re slower — surprisingly little is known about the actual bodily underpinnings of the decline. But there have been hints. Past studies have found that our aerobic capacity declines as we reach our 40s, dropping by about 10 percent per decade after that, even if we vigorously exercise. So a serious 60-year-old runner will have more endurance capacity than sedentary people his or her age, but less than his or her 40- or 50-year-old self.

However, lower endurance capacity does not automatically mean slower running speeds. Theoretically, with age, we could run at the same pace as we once did, although doing so would require using more of our already diminished endurance capacity — meaning that it would feel more difficult.

But we don’t. We slow down.

That process intrigued Paul DeVita, a professor of kinesiology at East Carolina University in Greenville, N.C., and president of the American Society of Biomechanics. In 2000, he and his colleague Tibor Hortobagyi published a famous study showing that older people, when they walk, take shorter steps than younger walkers, and rely less on the muscles around their ankles and more on the muscles around their hips to complete each stride than do younger walkers.

Source: New York Times

Running marathons or completing other ultra-endurance events is not necessarily bad for the heart, although it could be. But first, a clarification: By standard definitions of exercise intensity, running or jogging is moderate or even vigorous exercise. During such exertion, the heart works hard to supply blood to working muscles and over time becomes stronger and somewhat larger.

Research has been unclear on whether these changes can become harmful. Multiple studies have shown that immediately after running a marathon, most racers show increased levels of a protein associated with cardiac damage. But those levels soon return to normal, with no lingering damage.

Years of prolonged and repeated endurance training and racing, however, might have more pronounced, lasting and worrisome effects. A 2011 study of aging former Olympic runners and rowers from Britain, for instance, found that compared with healthy but unathletic men of the same age, the retired Olympians were disproportionately more likely to have scarring within their heart muscles. Similarly, in a 2013 study, people who had competed multiple times in a grueling, 56-mile cross-country ski race in Sweden had a much-higher-than-normal risk of developing heart arrhythmia within five years.

But these studies, although disquieting, “do not mean that it has suddenly become dangerous to exercise,” said Kasper Andersen, a professor at Uppsala University in Sweden who led the study of skiers. In fact, an earlier study from his lab found that, over all, participants in the ski race had a below-average risk of premature death.

Even the Olympians with heart scarring seemed largely unaffected. They were running and competing well into their 60s and 70s, that study found. Conceivably, the researchers wrote, the Olympians’ cardiac changes, which would be undesirable in most people, were normal in lifelong endurance athletes.

At this point, scientists just do not know precisely how years of endurance training might affect the heart.

So the best advice for those who enjoy endurance training is “carry on as usual,” Dr. Andersen said. “But remember to listen to your body and seek a doctor if you experience any symptoms from the heart.”

Source: New York Times

The Presidential Healthcare Center uses cardiac imaging to screen for “Athletic Heart Syndrome”