Do I have to work out for an hour a day?
Simply put: no! Over time, after a few months, say, you may find you want to because it feels so great. Certainly don't start by trying to immediately "work-out" an hour a day.
Start simply, easily, by walking just ten minutes a day. Or dance, play tennis, do light yoga, swim, bicycle, etc., whatever you like to do, if you’re up to it. Increase your time by ten minutes each week. In other words, the first week be sure you find a way to be active ten minutes a day, the second week twenty minutes a day, the third week thirty minutes a day. If that’s too fast, try increasing by five minute intervals. Remember, pain is no gain. And ask your doctor before embarking on any new activity plan.