Author Affiliations: K. G. Jebsen Center of Exercise in Medicine, Norwegian University of Science and Technology, Trondheim, Norway (firstname.lastname@example.org).
In Reply: Ideally, the same method of measuring RHR should have been used at both occasions, but both measurements of RHR in our study were performed in compliance with published guidelines.1 In both HUNT-1 and HUNT-2, RHR was monitored by trained nurses, making it unlikely that the variability in RHR measurements was affected by differences between observers. It is therefore difficult to envision that different measurement methods could explain the small reduction in RHR (0.4 beats/min) over 10 years.
Wisløff U, Nauman J, Vatten LJ. Changes in Resting Heart Rate Over Time and Mortality—Reply. JAMA. 2012;307(13):1369-1370. doi:10.1001/jama.2012.392