Researchers at Chicago’s Wellness Institute in Northwestern Memorial Hospital, have for the first time have established a fitness chart based on an age-wise correlation to the amount of exercise a healthy woman should be able to do, finding that the woman’s capacity is slightly lower than a man's and declines faster with age. They also found startling evidence that women whose exercise capacity was less than 85 percent of the suggested capacity were twice as likely to die within eight years.
Gulati and a fellow researcher, who have a patent pending for the guideline have reported their findings in the New England Journal of Medicine and believe that given women’s longevity, the results emphasize the need for their fitness. The research was based on treadmill stress tests used to diagnose cardiac disease, performed in 1992 on 5,721 women above 35 from the Chicago area, who had no symptoms or history of heart disease. The women were given a standard stress test with increasing speed and incline every three minutes until they became fatigued or unable to continue.
Until this, the only fitness guidelines available to women were based on men, wherein women had to read their fitness levels as if they were little men. But over the years, with more women participating in medical research, it has been clear that gender differences do exist in health, diseases and ageing. Dr. Martha Gulati, a cardiologist who led the study said of the difference, "In general, women's fitness levels seem to be lower regardless of her age than for men". While it is known that fitness declines with age, the research indicated that the gender difference in fitness became more pronounced with age, with women losing about 1 percent of their exercise capacity per year. The researchers also evaluated their guidelines in terms of how well survival could be predicted by following volunteers for eight years and another group of 4,471 heart-disease prone women for five years.
The exercise capacity estimations were made in metabolic equivalents (METs), based on the speed and grade of the treadmill with one MET per minutes being equivalent of the amount of energy or oxygen used to sit quietly, while 3 to 6 METs per minute for moderate walking and over 6 METs per minute for running. In devising the fitness chart, the researchers actually drew up a formula to determine the normal fitness level for women, which for example would say that a 50-year-old lady should be able to achieve 8.2 METs as against 9.2 METs for a man of that age. Dr. Gulati also said that it was not necessary for women to take the expensive stress tests that cost about $900 to find out their fitness levels, as even exercise machines at health clubs calculate the MET level of exercise done.
Mayo Clinic Cardiologist and spokesman for American Heart Association, Dr. Gerald Fletcher, said the women-specific guidelines would help doctors encourage patients who are not at high risk to reach their expected METs through more exercise. In New England Journal of Medicine’s accompanying editorial, recommended that doctors to quiz women patients about their exercise habits during their consultations, besides paying attention to the results of their stress tests.
