Accuracy of Heart-Rate-Recovery Parameters Assessed From a Wrist-Worn Photoplethysmography Monitor (Polar Unite).

If a wrist-worn PPG monitor is used to assess HRR, we recommend performing the submaximal-intensity exercise on a bicycle ergometer and focusing on Δ60. Furthermore, to obtain a more accurate Δ60, the time lag between the end of the exercise and the effective decrease in HR should also be considered before the calculation.