Topic: College of Applied Sciences and Technology

October 3, 2007

It may sound simple, but exercise — particularly the strenuous workouts of highly competitive distance runners — contributes to a healthy, long-lasting life, says research from a new Ball State study.

The first longitudinal study of the performances of elite distance runners found the cardiovascular and respiratory systems of such highly trained individuals decline at a slower rate over time as compared to moderately trained and untrained individuals.

The study found that runners on intense training schedules lose aerobic capacity at a rate of about 0.5 percent per decade. Moderately trained runners see a 1 percent decline per decade, and untrained individuals suffer a 1.5 percent decline every 10 years.

"While there is very little data on people who have been lifelong participants in various types of exercise and their fitness levels, our study found that runners stay healthier over a longer period of time," said Scott Trappe, director of Ball State's Human Performance Lab (HPL), which has been studying how exercise can benefit America's aging population since the 1960s.

"While these are highly training individuals, the results show that there is no question exercise is good for the body," he said. "The more you exercise, the healthier you should be over your lifetime."

The HPL's research is based on tests of 50 top distance runners to examine how aging impacts their running times and bodies over the last 40 years. HPL researchers were able to test top runners in the late 1960s and early 1970s, and then retest the same individuals many years later.

Trappe found that "running economy," as measured by the amount of oxygen needed to run at a given submaximal speed, and heart rate were similar after 20 to 25 years for highly trained individuals as compared to untrained men, who utilized more oxygen and have a much higher heart rate during their workouts.

The study also found that many years of hard training allow highly trained distance runners to maintain the aerobic capacity of their muscles at much higher levels as compared to untrained or sedentary people.

An examination of veteran runners found that their muscle fibers tend to be smaller,  contract faster and produce less power, but their bodies have adapted to strenuous training by developing better muscle cell ergonomics.

"While having smaller muscle fibers may seem to be a disadvantage for sports performance, it is most likely a physiological adaptation that is advantageous for distance running," Trappe said. "The muscle fibers from distance runners don't need a lot of power. They just need the ability to run for long distances at submaximal levels. The smaller fibers most likely aid in the transportation of oxygen, which fuels a runner's muscles."

He believes there is the opportunity to stretch the ability to continue exercising strenuously well past the current threshold of age 70.

"Our research supports that beyond the age of 60, there appears to be a substantial decline in aerobic capacity, which greatly impacts their performance and ability to tolerate high volume training, and at age 70, we see major loss of aerobic capacity," he said. "However, we are seeing more people in their 70s and 80s who have been exercising for many, many years enter competitive events. If we are able to refine training and diet, as well as keeping the joints healthy, we may be able to add more active and competitive years."