My friend Lois who loves her gym can be green wrote this article in response to my why working out at home is the greener Option Arguments in favor of a gym: I feel it's very interesting points.
I do think a gym that you can walk too or take public transportation to is greener than gym that is far away. You're also more likely to use a gym that's closer to you.
Here is the article.
Gyms can Be Green Too
By Lois June Wickstrom
1) Gyms have swimming pools. It is far more ecological to have a swimming pool that is shared by hundreds of people than to have one in your home.
2) Gyms have their own heating system. You can let your home cool down while you exercise at a heated gym (which is going to be heated whether or not you go.)
3) Gyms have classes. I can't make myself do yoga for 90 minutes at home, and I can't see myself to correct my postures. Therefore when I do yoga at the gym, I do it longer and I do it better.
4) Gyms have lots of equipment that I don't have at home. It's not ecological for me to buy weight machines that I'll use for 15 minutes 3 times a week. But like the swimming pool, it makes sense for the gym to buy them for hundreds of people to use.
5) Gyms have big hot water heaters that will be on whether or not I shower there. If I shower at the gym, that's more ecological hot water than if I shower at home. Same for the gym sauna and hot tub.
Lois sites are