Physical inactivity is the most important planetary reason for non-transmissible mortality. Technical developments have allowed a sedentary lifestyle. This causes health problems such as insulin resistance, atherosclerosis, heart failure and obesity. In addition, disturbances of bones and muscles as well as dementia of the Alzheimer type are associated with sedentarity. Assessing this risk factor and attempting to increase physical activity should be a very important part of any general practitioner's measures.