Or recognized for what they are: a rough approximation of a statistical average of academic interest only that has no utility for any particular individual. About 13 years ago I got into a long argument (in a running forum) with a nurse who worked for a cardiologist. She insisted that 220-age was accurate for everyone and that you were risking killing yourself if you ignored it. Drove me crazy. Unfortunately that forum was defunct & I no longer had her e-mail when I came across the NYT article. Would have loved to rub her nose in it ("Dr. Fritz Hagerman, an exercise physiologist at Ohio University, said he had learned from more than three decades of studying world class rowers that the whole idea of a formula to predict an individual's maximum heart rate was ludicrous."). Ha!