What Sitting All Day Is Actually Doing to Your Body

Right now, you're probably sitting. Many office workers spend 9 to 10 hours a day on their behinds, which is more than half of the time we're awake. But what is that actually doing inside your body? In this animated explainer, we follow what happens to your legs, blood, back, brain and metabolism when you sit still for hours. We also cover what the research says you can do about it. (Spoiler: you don't need to stop sitting. You need to stop sitting STILL.) In this video you'll learn: ✅ Why your biggest muscles practically switch off when you sit ✅ How idle muscles affect blood sugar, insulin and fat in your blood ✅ The "second heart" in your calves, and why blood pools when you sit still ✅ What 3 hours of sitting does to your arteries, and how fidgeting helps ✅ Why your spinal discs need movement (and why you're taller in the morning) ✅ Why there's no single "perfect posture" ✅ How much your head "weighs" when you look down at your phone ✅ Is sitting really the new smoking? ✅ How much activity seems to cancel out the risks of long sitting ✅ 4 simple habits: break it up, use your calves, mix it up, move a little every day ⏱️ CHAPTERS 0:00 You're probably sitting right now 0:42 What hunter-gatherers do differently 1:10 Your legs: your biggest muscles switch off 2:41 Your blood: the "second heart" in your calves 3:55 Your back, neck and hips 5:25 Your brain 6:04 Your energy: the calories you don't burn 6:46 How bad is it? 7:00 Is sitting the new smoking? 8:01 What you can actually do 9:15 Stop sitting still 📚 SOURCES • Ekelund U. et al. (2016). Does physical activity attenuate, or even eliminate, the detrimental association of sitting time with mortality? The Lancet. • Sagelv E.H. et al. (2023). Device-measured physical activity, sedentary time, and risk of all-cause mortality. British Journal of Sports Medicine. • Biswas A. et al. (2015). Sedentary time and its association with risk for disease incidence, mortality, and hospitalization in adults. Annals of Internal Medicine. • Dunstan D.W. et al. (2012). Breaking up prolonged sitting reduces postprandial glucose and insulin responses. Diabetes Care. • Bey L. & Hamilton M.T. (2003). Suppression of skeletal muscle lipoprotein lipase activity during physical inactivity. Journal of Physiology. • Thosar S.S. et al. (2015). Effect of prolonged sitting and breaks in sitting time on endothelial function. Medicine & Science in Sports & Exercise. • Morishima T. et al. (2016). Prolonged sitting-induced leg endothelial dysfunction is prevented by fidgeting. American Journal of Physiology: Heart and Circulatory Physiology. • Carter S.E. et al. (2018). Regular walking breaks prevent the decline in cerebral blood flow associated with prolonged sitting. Journal of Applied Physiology. • Oppezzo M. & Schwartz D.L. (2014). Give your ideas some legs: the positive effect of walking on creative thinking. Journal of Experimental Psychology: Learning, Memory, and Cognition. • Levine J.A. et al. (2005). Interindividual variation in posture allocation: possible role in human obesity. Science. • Raichlen D.A. et al. (2020). Sitting, squatting, and the evolutionary biology of human inactivity. PNAS. • Hamilton M.T. et al. (2022). A potent physiological method to magnify and sustain soleus oxidative metabolism improves glucose and lipid regulation. iScience. • Hansraj K.K. (2014). Assessment of stresses in the cervical spine caused by posture and position of the head. Surgical Technology International. • Saeidifard F. et al. (2018). Differences of energy expenditure while sitting versus standing: a systematic review and meta-analysis. European Journal of Preventive Cardiology.