shortage of exercise

I haven't been getting enough exercise since I started working. Come to think of it, it was not enough in my collage days even though I sometimes played tennis. I feel lack of exercise these days. The other day I went to see a movie with my friends, we talked about our shortage of exercise and needs of exercise. However this kind of plan is easy to go up in somke. My friens seem to not like activities. Especially they don't like, for example, just running or walking. I think that they need a sense of game or meaningful activities. In fact we had to move our body whenever we did anything in old times. Now that we can use the Internet to do something for free, that contributes our lack of exercise. We live in cynical time. I wonder if there are some no-money sports we can enjoy.