Wonder if you should start running? The New Scientist magazine reported that a Yale University study showed that endurance athletes, such as long-distance runners, burn up extra calories even when at rest- while your reading a book, watching TV, sleep or just hanging with friends.
Mitochondria is the part of a cell which convert sugar and fat into ATP molecules, which transport energy within cells. The study showed that the mitochondria in the cells of men who run (treadmills or outside) for four or more hours each week, use 54% more fuel than the mitrochondria of non-runners.
When the mitrochondria uses sugar and fat, this helps to clear out cellular fats that may contribute to insulin resistance. This research suggests that, even when at rest, running plays an important role in helping to protect against type 2 diabetes, as well as helping to burn fat.
4 hours a week is not that much. Break it into 6 days- that's 40 minutes a day, with rest on one day of the week :) So, get those running shoes out and start running.