Work

Who’s Been Sleeping in My Bedroom? Associations Between Co-Sleeping with Dogs, Cats, or Children and Sleep and Cardiorespiratory Physiology Among WHOOP Users

Year: 2026

Type: article

Abstract: Purpose: Co-sleeping with pets or children is common, yet its associations with sleep, cardiorespiratory physiology, and behavioral outcomes are understudied. We examined within-person associations between co-sleeping with a dog, cat, or child and sleep characteristics, measures of cardiorespiratory physiology, and next-day physical activity. Methods: We analyzed 1,649,083 person-days from 11,733 adults wearing the WHOOP wearable device. Participants self-reported nightly co-sleeping via a daily journal in the device's companion smartphone application. Linear mixed-effects models compared nights with and without co-sleeping within the same individual. Results: Co-sleeping was associated with lower resting heart rate (0.8-1.1 beats/min), lower respiratory rate (0.04-0.07 breaths/min), and higher heart rate variability (1.41-1.95 ms). Sleep outcomes were mixed, with longer sleep duration (5.5-9.6 min) but more disturbances (0.36-0.40 instances) and slightly less restorative sleep (0.23-1.17%). Associations were generally consistent across groups, although child co-sleeping was associated with greater sleep disruption. Next-day physical activity was higher following dog and cat co-sleeping (7.6 and 7.4 intensity-weighted min, respectively) but lower following child co-sleeping (-2.6 intensity-weighted min). Despite statistical significance, all standardized effect sizes were small (β range: 0.008-0.045). Conclusion: Co-sleeping was associated with small differences in cardiorespiratory physiology (lower resting heart rate, higher heart rate variability) alongside mildly greater sleep disruption. The small magnitude of these associations suggests that co-sleeping decisions may be influenced more by personal and contextual factors than by expectations of substantive physiologic or sleep-related impacts.

Source: Nature and Science of Sleep

DOI: 10.2147/nss.s636142

Authors: Alexander HK Montoye, Dylan J Curran, Gregory J Grosicki

Institutions: Montcalm Community College, Michigan State University, Georgia Institute of Technology

Language: English

Topic: Sleep and related disorders

Subfield: Experimental and Cognitive Psychology

Field: Psychology

Domain: Social Sciences

SDG: Good health and well-being

Open Access status: gold

Estimated APC paid: $2,836