Researchers develop chart to help women gauge fitness, reduce risk of death

TORONTO (CP) - For the first time, researchers have developed a chart that can tell women what level of exercise they need to stay fit at any given age. A study conducted by the same team reveals that falling short of the age-specific exercise targets can significantly increase the risk of death.

"Despite extensive research on the role of exercise stress testing and exercise capacity, there has been a lack of data on what is normal or expected for healthy women," said lead researcher Dr. Martha Gulati, a cardiologist at Northwestern Memorial Hospital.

Gulati said until now, women have been evaluated using a nomogram or chart developed for men.

"We are finding - surprise, surprise - that women are not small men, they are women," she said Wednesday from Chicago.

"The fact is we need guidelines for women that are based on women. We now have that set of standards for women."

The chart shows what level of exercise is needed at any age to reach maximum fitness. Any result greater than 100 per cent indicates better-than-average performance; any below that indicates some degree of functional impairment for age.

So, for instance, a 60-year-old woman performing at a level of seven METs on a treadmill would intersect the graph at 100 per cent of her age-predicted fitness level. (METs are a measurement of the intensity of physical activity.)

But a 30-year-old achieving seven METs would reach only 62 per cent capacity, a level that could prove dangerous over time, said Gulati, a Canadian from Bright's Grove, Ont., who trained at the University of Toronto.

That's because a long-term study by Gulati and fellow researchers found that an exercise capacity below 85 per cent boosted the risk of death.

The study, published in Thursday's New England Journal of Medicine, looked at 5,721 women with no symptoms of heart disease and 4,471 symptomatic women, all of whom were given treadmill stress tests. The nomogram was then used to determine the percentage of predicted exercise capacity for both groups.

The researchers kept track of the women, following how many had died and of what causes by the end of 2000, then correlated mortality rates and exercise capacity.

"For those women who achieved less than 85 per cent of their age-predicted fitness level, they were twice as likely to die from any cause," said Gulati, "and they were almost two and half times more likely to die from cardiac causes."

Many exercise machines in gyms, such as treadmills and stationary bikes, show how many METs are being performed during a workout. "But most people don't know what they mean so they ignore them," she said, noting that the nomogram could help women tailor their workouts to achieve optimal exercise capacity for their age.

Gulati hopes organizations such as the Heart and Stroke Foundation and the American Heart Association will endorse the use of the women's nomogram to doctors, who could use it to help assess fitness levels of their female patients.

"We screen for their high blood pressure. We screen for their cholesterol. We need to be screening for their fitness," she said. "This is just as important as any other traditional cardiac risk factor."

More details in a moment.