Beginning a swim program will help benefit your other athletic endeavors. Just like swimmers partake in dry land workouts to improve their bodies ability to swim better. If you have been a runner for the better part of your life the injuries you sustain can be worked out in the pool. You say but I want to run…how about running in the pool. There are devices that will help you float enough to keep your feet off of the pool floor. You can run from one end to the other. Give yourself different a certain amount of time to get to the other end. Do sprints like you would on a running track. Make the next set perhaps a bit easier then do another hard set. You will find the plantar fasciitis is no longer bothering you. The knee pain is less than it used to be. Now you can hit the pavement again, but don’t forget what helped you get better after all water is a benefit for all athletes.