Two people, same age, different max heart rates. That's the premise behind the Nes et al. formula, and it's a departure from almost every other age-based equation in this space.

Dr. Hirofumi Tanaka set out to correct that with a meta-analysis pulling together data from thousands of individuals across a wide age range. The result was a formula with a smaller average error and a track record that holds up better across different ages and fitness levels.