Study warns of risks from prolonged sitting, while light movement may lower cancer death risk

How people distribute their sitting time may matter as much as how many hours they spend inactive, a recent scientific study suggests. Long, uninterrupted periods of sitting appeared to carry greater health risks than inactivity broken up by brief movement.

Researchers used data from more than 91,000 participants in the UK Biobank. The participants wore activity monitors for one week, then underwent health follow-up lasting an average of more than 12 years.

The study focused on periods of near-total inactivity lasting at least 30 minutes. Researchers treated these stretches as continuous inactivity and compared them with inactive periods interrupted by short movements or activities.

Participants who spent more time in uninterrupted inactivity faced higher health risks, including a greater likelihood of dying from cancer. Overall cancer incidence also increased, as did rates of some cancers associated with obesity and type 2 diabetes. By contrast, spreading sitting across the day with brief movement breaks appeared to reduce some of the risks.