Authors' reply

摘要

We read with interest the article by Peter Kokkinos and colleagues.1 Although cardiorespiratory fitness is developed by physical activity, they are different, and they are linked differently to cardiovascular disease, with cardiorespiratory fitness having a stronger protective association.2 Being inactive and being unfit are independent risk factors, and inactivity might not be a cause of being unfit. Thus, recommendation of physical activity basis of the cardiorespiratory fitness status might not be entirely appropriate.