Number on scale may not be as important as overall fitness

Women with a high level of cardiorespiratory fitness (CRF), regardless of weight, have lower all-cause mortality than less-fit women who weigh less, according to a recent study from Texas.

Researchers followed a total of 11,335 women who had a baseline physical examination between 1970 and 2005 that included measurements of body mass index (BMI), waist circumference, waist-to-height ratio, waist-to-hip ratio, percent body fat, and the results of a CRF treadmill test. The subjects were stratified as having low (lowest 20%), moderate (middle 40%), or high (highest 40%) CRF, and by standard clinical cutpoints for adiposity.

The researchers found that the women with moderate and high CRF had a lower risk for death than the women with low CRF (hazard ratio [HR], 0.60 and 0.54, respectively). Although death rates for overweight women were somewhat higher than for women of normal weight and approached statistical significance for BMI, percent body fat, and waist-to-height ratio, the women with higher CRF who also had higher body fat percentages, waist circumference, and waist-to-height ratio had a death risk similar to that of fit, normal-weight women.

Farrell SW, Fitzgerald SJ, McAuley PA, et al. Cardiorespiratory fitness, adiposity, and all-cause mortality in women. Med Sci Sports Exerc. 2010;42(11):2006–2012.