Study record · validation · 2020

A validation study of the WHOOP strap against polysomnography to assess sleep

Miller DJ, Lastella M, Scanlan AT, Bellenger C, Halson SL, Roach GD, et al.

Journal of Sports Sciences, 38(22), 2631-2636 · 2020

Why this study matters to CircaTest

The only published independent PSG validation of a WHOOP device. CircaTest cites this as the canonical Whoop accuracy reference. The 64% four-stage agreement and the 8.2 ± 32.9 min TST overestimation are both editorially load-bearing.

Abstract

The aim of the study was to compare the WHOOP strap, a wearable device that estimates sleep based on measures of movement and heart rate derived from actigraphy and photoplethysmography, against polysomnography.…

Read the full abstract on the source →

Source: PUBMED · Excerpt for fair-use commentary; full abstract via the source link

Population

Sample size

n = 12

Age

22.9 ± 3.4 years

Reference standard

psg

12 healthy adults (6 female, 6 male) in a 10-day in-laboratory protocol producing 86 polysomnography-scored sleep sessions.

Devices and metrics

WHOOP strap (predecessor of Whoop 4.0)

All studies for this device →

Metric	Value	95% CI	Note
Epoch-by-epoch agreement	64%	—	Four-stage categorisation (Wake, Light NREM, Slow-Wave Sleep, REM).
Cohen's kappa	κ = 0.47	—	Four-stage Cohen's kappa.
Accuracy	89%	—	Two-stage (sleep vs wake) agreement.
Cohen's kappa	κ = 0.49	—	Two-stage (sleep vs wake) Cohen's kappa.
Sensitivity	95%	—	Sensitivity to sleep (two-stage).
Specificity	51%	—	Specificity for wake (two-stage).
Bias (minutes)	8.2 min	—	TST overestimation, non-significant; SD ±32.9 min.

Cite this study

Miller DJ, Lastella M, Scanlan AT, Bellenger C, Halson SL, Roach GD, et al. (2020). A validation study of the WHOOP strap against polysomnography to assess sleep. Journal of Sports Sciences, 38(22), 2631-2636. https://doi.org/10.1080/02640414.2020.1797448

AI-assembled record · errors are possible

This page was built and is maintained by AI working from the published abstract and PubMed metadata for the cited study. CircaTest does not have access to the full text of every paper in its corpus. Categories of error that have happened on this site and could happen again include:

Per-device metric values inferred when the abstract reports only an aggregate range
Stage-specific accuracy figures pulled from secondary sources rather than the primary paper
Sample size or population characteristics missing from the abstract
Editorial framing in the curatorial note that overstates the study's actual scope
Year typos and author-name transliteration errors

Where a metric value reads see source, the published abstract did not contain that value and CircaTest deliberately left it null rather than guess. For any decision that depends on the underlying numbers, please consult the linked PubMed, PMC, or DOI source directly. Corrections are welcome via the about page.

Source links

Added to the CircaTest meta-analysis on 2026-04-06. How CircaTest evaluates studies →