Can 15 minutes of activity reduce the dangers of prolonged sitting A study published in the journal JAMA Network Open, observed approximately 480,000 participants over a 13 year period. The study revealed that individuals who spent a significant portion of their day sitting had a 16% higher risk of overall mortality and a 34% higher risk of mortality from cardiovascular disease compared to those with less sedentary occupations. In addition, those who predominantly sat at wo