Monitoring The Early Physiological Effects of Fitness Regimes Using PPG Signals

This paper records a study to investigate the feasibility of using photophlethysmogram (PPG) based system for monitoring the effectiveness of fitness regimes on wellness of working professionals. For this study Yoga was used as the fitness intervention. Although monitoring the health benefits of Yoga over longer periods (eg. 2–3 months) has been performed using various methods, the monitoring of the effect of Yoga over shorter duration (1 to 2 weeks) is difficult and the effect is often not visible in the conventional features considered for PPG analysis. Using PPG signals collected before and after a 12-day program of Yoga sessions, we analyzed the effect of Yoga on the Pulse rate, Pulse harmonics and Heart Rate Variability (HRV). The time and frequency domain characteristics of the PPG signal were analyzed and their variations over the period was evaluated along with the power of the harmonics. We show that short term effect is evident in the harmonics of the PPG signal and some of the key HRV features. The power corresponding to the higher harmonics and 7 of the key HRV features showed good separation between Day 1 and Day 12 with p <0.05.