This calculator is a hoot to use. I highly recommend taking the time (just a few minutes) to answer all the detailed questions. Based on the inputs, the calculator (developed by actual scientists and not wellness vendors, app makers, or God forbid, physicians) estimates my fitness age as 28. I’m 59.

I’ve used other calculator before, and they pretty much all tell me the same thing. A lifelong habit of regular exercise has paid (and continues to pay) huge benefits in physiologic function, biomarkers, quality of life, mood, outlook, and just about anything else you can think of. Exercise IS the fountain of youth.

Aging is an inevitable fact of life.

But if you exercise pretty frequently and eat right, you might be a lot younger than you think — at least as far as something called your “fitness age” is concerned.

Business Insider: Scientists made an online calculator that tells you your ‘fitness age’ — and you can try it right now.