Long sitting was linked to earlier death. Not clearly in active women.

Cohort study. 58,168 people. 6-year exposure window (Y0 1993-1998 to Y6), then median 15.0 years (IQR 13.5-16.0) of mortality follow-up through March 2019.

People were watched for years. Nobody was told what to do. A clue, not proof.

Who: Multiethnic US postmenopausal women aged 50-79 at baseline (~85% White), without CVD or cancer by Y6, not underweight at Y0, alive 1 year after Y6; recruited at 40 US clinical centres

• Sat 8+ hours a day+14%higher death risk
• Active at both checks-22%lower death risk
• Sitting risk if activeno clear+16% if inactive

More to know, from our read of the paper:

• Observational cohort: associations, not causation; authors say a causal reading 'is not guaranteed' and residual confounding (e.g. subclinical illness) is possible
• Sitting time and exercise were self-reported by questionnaire, not device-measured
• Only two time points (Y0, Y6) define the transitions; Y3 data showed patterns were mostly stable (76% of consistently sedentary, 87% of consistently active stayed so at Y3)
• 'Sedentary' = self-reported sitting >= 8 h/day; 'active' = recreational activity >= 8.5 MET-h/week (authors: approximates >= 150 min/week moderate activity, or ~2 h brisk walking at 3.5 mph per week). Work, household and transport activity not counted
• The 'active women: no clear extra risk from sitting' result is an interaction analysis with binary groups (unfavourable vs favourable sitting: HR 1.04, 95% CI 0.99-1.09 among favourable-activity women vs 1.16, 1.12-1.21 among unfavourable-activity women; P-interaction < 0.001). Say 'no clear extra risk', never 'exercise cancels sitting'. Held for all-cause and CVD mortality only, not other causes

This US study followed 58,168 women past menopause (aged 50-79 at the start). They reported their sitting time and leisure exercise twice, six years apart, and were then followed for a median of 15 years. Sitting 8 or more hours a day at both checks was linked to 14% higher risk of death, and staying active at both checks to 22% lower risk. In women who stayed or became active, long sitting showed no clear extra risk. Everything was self-reported and the design is observational: linked, not proven.

We read the abstract and the full text of this paper and checked every number on this page against it (17 facts, checked on 2026-10-29). The study design is named above. Cohort and other observational studies are described as linked, not proven. Found an error? Email theis@onestudyaday.com.