So I've lost 40 pounds triggered by DHs diabetes diagnosis. Now light enough to consider exercise. I work full time in a stressful job along with 3 kids so I'm busy. I know I need to exercise as my sleep is terrible and has been for years. I used to run and would always sleep well after a run. But time is short and my motivation pretty low. Getting out in the evening is tricky so I've bought a treadmill. How long or little time do I need to be on it to get any health benefits?