Maybe work on your physical health. Start exercising/working out with some goal to reach like losing xx amount of weight. Or maybe walking/running/biking/swimming with a goal to be able to reach XX mi/km or whatever. Or train to be able to compete in some amateur walking/running/biking/swimming event. Or take up an organized team sport to help give you more structure to help keep you at it.
Sure, this or couples of other things could work out too. if you're determined to stay away from gambling, but most of the folks aren't determined. that's why they gamble again and again and lose their hard earned money.