If you smoke cigarettes and you want to quit (and you should), do something else to take its place. Low-impact exercise is a pretty good thing to do. You will be surprised at how quickly you can do stuff that you were not able to do before. I started walking two miles every morning, but now I am up to five. At fifteen minutes a mile, it is a brisk walk but not too taxing. Another nice thing about walking is that if it is cold outside all you have to do is bundle up. Another nice thing about walking is that you don't need to buy any kind of "work-out" clothes or shoes. I just wear regular clothes and have a nice pair of shoes suitable for walking that I already owned anyway. After my morning walk, I do twenty push-ups and twenty sit-ups. I started at ten apiece, but when that became easy enough I increased each to fifteen. Now I am at twenty. None of this costs me a penny. In the afternoon, I walk to the library to study, and then back. Another three miles.

Start small, and work your way up gradually. Set small but achievable goals. Find something to do that you enjoy, and then have fun with it. I like walking because it is meditative. But maybe you like something more exciting. That's cool. Do what you find is fun. Often what is fun requires zero money out-of-pocket.