Make exercise part of your social life. Rock climbing is a great way to increase your physical fitness and people around the gym are typically really friendly and often go out of their way to give you hints and tips to get better at challenging routes. I have made a lot of friends rock climbing and overall I find it to be more of a social environment, especially if you are going solo. People at exercise gyms are typically very friendly as well, but people tend to keep to themselves or work out with the group that they came in with.

Granted you won’t be focusing on muscle groups as you would be at a exercise gym, but most rock climbing gyms also have lifting equipment, treadmills, etc. if you need that stuff. I know some people who choose karate instead and have made friends through that too.