Nikolaidis et al. 2018, Age-predicted maximal heart rate in marathon runners

Study of measured maximal heart rate in recreational marathon runners. Measured HRmax varied widely around the age-formula prediction (standard deviation about 8.8 bpm in women and 10.4 bpm in men), and the Fox and Tanaka formulas over- or under-estimated by several beats depending on sex. Confirms that estimated HRmax is too imprecise to anchor exact zones. Strong.