Not trying to plug this too hard, but being a Curves member helps me stay fit during the winter. I will do some outside stuff as well, but not enough to replace the biking I do in the better seasons. Curves now has Zumba dancing being offered as part of the workout, and that helps with the boredom people get from doing the same routine repeatedly. I think part of the problem is that people think it is a workout for "old ladies" and I am here to tell you guys that it IS what you put into it. I typically don't gain any weight or body fat during the winter, and I haven't drastically modified my eating habits. I might even be eating more because I do that when it's cold, I get hungrier quicker.