The research study included over twenty thousand people. It measure fitness in relation to an age variable. The significant age mark seems to be forty five:
“… “The U.S. population is aging and is becoming more obese and sedentary,” Andrew Jackson, PED, from the University of Houston and colleagues write in the Oct. 26 issue of Archives of Internal Medicine. “It is well documented that the cardiorespiratory fitness of men and women declines with age and that body composition and habitual physical activity are related to cardiorespiratory fitness.
They add that low fitness levels increase the risk of diseases and interfere with the ability of older adults to function independently.”
link to the article by Bill Hendrick for WebMD Health News
additional link: Fitness Fades Fast After 45
