Ever since high-density lipoprotein (HDL)-cholesterol, as a measure of the HDLs, was found to be elevated in crosscountry skiers1 and marathon runners,2 investigators have debated whether this is a self-selection phenomenon, ie, skinny athletic persons naturally have higher HDL levels and are attracted to long-distance competitive sports because they are easy for them to do or that somehow increased physical activity changes body metabolism producing a rise in the HDL level.
A series of reports has begun to appear where a group of persons (sometimes patients, sometimes volunteer medical students)3,4 have had their HDL levels characterized before entering into an exercise program that demonstrated the eventual rise in their HDL level during exercise.
Two articles in this issue of The Journal extend these observations to patients with coronary heart disease. Both focus on the now well-known fact that subjects who experience coronary heart disease have low HDL