In this episode of Longevity by Design, host Dr. Gil Blander speaks with Dr. Keith Diaz, Associate Professor of Behavioural Medicine at Columbia University and expert on sedentary behaviour. Together, they explore how prolonged sitting impacts the body, why exercise alone doesn’t undo the harms of sitting, and what simple strategies can help us move toward a healthier, longer life.

Key Points:

Prolonged sitting is far more than just a comfort issue—it alters how our muscles, blood vessels, and metabolism function, raising the risk of heart disease, diabetes, and early death, even in people who exercise regularly. The good news is that the remedy doesn’t require drastic changes: weaving short bouts of movement—like walking for a few minutes each hour—into daily routines can dramatically improve health, mood, and longevity.

• Why Sitting is the “New Smoking”: Dr. Diaz began his research skeptical of the claim, but years of evidence show that prolonged sitting harms the body even in people who exercise regularly.
• The Physiology of Sitting: Muscles regulate blood sugar and fat levels only when activated. Sitting shuts them down, leading to blood sugar spikes, higher fat levels, and turbulence in blood flow that damages vessels—especially in the legs.
• Exercise Isn’t Enough: Even daily workouts can’t fully counteract the negative effects of 8+ hours of sitting. Movement throughout the day matters just as much as structured exercise.
• Movement Breaks: The “Magic Dose”: Lab tests show that as little as five minutes of walking every hour lowers blood pressure, boosts mood, and reduces fatigue. Even one minute helps, but more is better.
• Technology and Behaviour Change: Wearables can nudge people to move, but the long-term goal is to integrate breaks naturally into routines—like taking a walk after meetings or during phone calls.
• Rethinking Culture and Policy: Dr. Diaz argues that schools, workplaces, and insurers should treat sitting as an occupational hazard and build in incentives and environments that encourage movement from childhood onward.