Researchers found small but consistent rises in systolic and diastolic pressure within minutes in otherwise healthy adults, with levels easing once neutral sitting posture was restored.
The study says crossing one thigh over the other can compress the artery behind the knee, restrict blood flow and prompt compensatory vascular and cardiac responses while the posture is maintained.
It warns repeated modest increases may matter for people with hypertension, diabetes or vascular disease, and advises uncrossed legs during desk work and blood pressure checks.
For healthy adults, do these temporary blood pressure 'nudges' actually pose a long-term threat?
What psychological trick can break the subconscious habit of crossing your legs at work?