Validity of Four Consumer‐Grade Optical Heart Rate Sensors for Assessing Volume and Intensity Distribution of Physical Activity. - Neudorfer, Michael; Kumar, Devender; Smeddinck, Jan David; Kulnik, Stefan Tino; Niebauer, Josef; Treff, Gunnar; Sareban, Mahdi (Scandinavian Journal of Medicine & Science in Sports (John Wiley & Sons, Inc.), 2024)