From The New York Times:
For people in midlife, this simple measure of fitness may help predict their risk of heart problems as they age. In two separate studies, researchers from the University of Texas Southwestern Medical School and the Cooper Institute in Dallas analyzed fitness levels for more than 66,000 people. Over all, the research showed that a person’s fitness level at midlife is a strong predictor of long-term heart health, proving just as reliable as traditional risk factors like cholesterol level or high blood pressure. The two reports were published last month in Circulation and The Journal of the American College of Cardiology.
In the studies, fitness was measured using carefully monitored treadmill testing to gauge cardiovascular endurance and muscle fatigue. But in analyzing the data, the researchers suggested that the treadmill results could be translated to average mile times, offering a simple formula for doctors and individuals to rate their fitness level at midlife and predict long-term heart risk. “When you try to boil down fitness, what does fitness mean?” said Dr. Jarett D. Berry, assistant professor of internal medicine and cardiology at Southwestern Medical School and a co-author of both papers. “In both these studies, how fast you can run in midlife is very strongly associated with heart disease risk when you’re old. The exercise you do in your 40s is highly relevant to your heart disease risk in your 80s.”