Researchers at the San Francisco Veterans Affairs Medical Center and UC Berkeley have found a more reliable way to measure physical and cardiopulmonary fitness in elderly people. The researchers say the test requires less running time on the treadmill, and also should serve as a reliable fitness measure for heart disease and kidney failure patients.
The conventional treadmill exercise test, the gold standard for measuring exercise performance for more than half a century, requires a person to push his or her body until it reaches its maximum rate of oxygen consumption during exercise, known as VO2 max, said Milton Hollenberg, MD, a UCSF professor of cardiology at the San Francisco VA Medical Center.
But many people over 65 either can't or don't want to push themselves hard enough to reach their maximum oxygen intake. For some, completing the test requires an extreme exertion, and it can even be dangerous for those with heart disease or other problems, Hollenberg said. Instead, some researchers simply have measured the highest oxygen consumption achieved during the test, but several studies have proven that this measure is often unreliable.
For a better alternative, Hollenberg used findings from a largely ignored 1996 study on young Japanese children with heart disease. The scientists had used a measurement called OUES (Oxygen Uptake Efficiency Slope), which employs the same treadmill exercise, but relates the rate of oxygen consumption to ventilation (the rate of air intake at any given moment during the test.)
To test OUES in adults, Hollenberg and his colleagues applied it to data he had collected for 429 elderly people from Sonoma, California, who had reached maximum effort on an exercise test. The researchers calculated OUES using data for the entire test, and compared it with the same calculation using only the first 75 percent of the data, as if the patient had quit the test earlier. The two measurements differed by less t
University of California - San Francisco