I'll throw in a pitch for running. There's a great program out there called Couch to 5k which will easily get you ready to do a 5k race. You can even  do it while alternating walking and running, so it's very possible. 

http://www.reddit.com/r/C25K
http://www.reddit.com/r/running
http://www.coolrunning.com/engine/2/2_3/181.shtml



One recommendation to nofapprs is to exercise. Here is a good "getting started" guide from the fitness subreddit which actually has links to other subreddits. Some people like lifting, others running, and other do only bodyweight exercise. This and more is here:

http://www.reddit.com/r/Fitness/wiki/getting_started

I encourage you to share what works for you in the comments.

From NoFap to Fit