Got 20 minutes a day? That’s all you need to live longer. We’ve all heard about the dangers of sitting for too long, and if you’re one of the many office workers who sits in front of a computer for up to 10 hours a day, you need to make time for a new kind of break – an exercise break. A study found that just 20-25 minutes a day of exercise a day can reduce the risk of early death caused by a sedentary lifestyle.