Mindfulness-Based Stress Reduction (MBSR) is designed to help individuals regulate emotional and physiological states by increasing non-reactive awareness of internal experiences such as bodily sensations correlated with emotional states. Biofeedback also provides people with information about their internal physical states and could be combined with MBSR to make it more effective.

Sumińska et al. [PLOS One] tested if the effects of MBSR training could be enhanced with the aid of smartwatch-delivered physiological feedback. Their study compared outcomes from standard MBSR, MBSR augmented with smartwatch biofeedback, and a no-treatment control group on measures of stress and wellbeing.

The researchers randomly assigned 72 healthy Polish adults (average age = 29 years; 79% female) who had no prior meditation experience and reported high levels of stress to one of three study groups. The MBSR group followed the traditional eight-week group-based curriculum with a half-day retreat and daily home practice. The MBSR plus smartwatch group included an identical MBSR training and were given smartwatches which measured heart rate, breath frequency, and movement. The watches provided wearers with data on daily stress levels, sleep quality, and a balance indicator of sympathetic versus parasympathetic nervous system activity. 

Participants were instructed to view their smartwatch data twice daily, record their readings in a diary, and attend to notifications when their stress levels were elevated. All participants were assessed at baseline and after the 8-week intervention on conventional mental health self-report measures. Perceived stress was the primary outcome measure, and  depression, anxiety, rumination, and general psychological functioning served as secondary measures. 

The results showed both MBSR groups reported significantly decreased levels of stress (Cohen’s d=0.63 and 0.49), eating disorder symptoms (d=0.47 and 0.59) and rumination (d= 0.44 and 0.64) compared to their own baselines. The MBSR group had significant decreases in anxiety (d=0.50), cognitive difficulties (d=0.65), sleep problems (d=0.58) and a decrease in poor psychological functioning (d=0.54) compared to baseline. The control group reported a significant decrease in poor psychological functioning (d=0.68) compared to baseline.

Comparisons of post-intervention scores between groups showed the MBSR plus smartwatch group showed a significantly lower level of stress (η2 = 0.10) than the other groups, and the MBSR only group had significantly lower levels of rumination (η2 =0.15) than the other groups.

The study findings suggest that adding smartwatch biofeedback to MBSR may modestly enhance its effect in reducing perceived stress. However, adding a smartwatch does not appear to extend additional benefits to anxiety, rumination, cognitive difficulties, and sleep problems, and may even interfere with those benefits. A main limitation was the lack of testing for formal group-by-time interactions to clearly evaluate the between-group contrasts in this trial. Thus, all results are preliminary.  

Reference:

Sumińska, S., & Rynkiewicz, A. (2025). Mindfulness-based stress reduction training supplemented with physiological signals from smartwatch improves mindfulness and reduces stress, but not anxiety and depression. PLOS One.

Link to study