If your outdoor routine is getting cut short due to weather and air quality, or if you're just ready to take your fitness to a new level then you may want to think about joining a gym.
I know it sounds daunting, but there are a lot of gyms out there just dying to give you a free guest pass so you can try out their facilities. Gymticket.com has done the preliminary work for you so all you have to do is search for a nearby gym and show up. You can even print your free guest passes directly from the site, which means you'll avoid dealing with potentially pushy salespeople (at least in the beginning). So take your time and try out all the gyms near you until you find the one that you'll actually end up going to. You may even find that you actually enjoy going to the gym.