You want to work that old heart of yours
Look for some good cardio exercises, running can be tough on the knees, seeing as you are in Arkansas the weather should be decent most of the time.
Biking is a great way to build your cardio, and your legs. Trevor Linden and Pavel Bure used to hit the hills frequently (up hill biking is great for cardio and your legs) Judging by one of bure's hockey cards him and his brother used to roller blade as well (in short shorts)
Also swimming is really good, if you have creaky bones and bad joints swimming is the best way to go. There are 100 different exercises you can do in a pool. Most strokes are good for an overall body workout (go hard, try not to drown
) If you want to work the legs grab a flutter board hold it in front of you and kick your legs hard, you look funny, but it gives a nice burn!
Hope that helps