Reply #11: That's why running can be a great means of getting exercise.

[Telly Savalas]

You go to road races and you'll find a whole culture of people who are obsessed with their personal bests at various distances, whether it's folks trying to do a sub-3 hour marathon or finish a 5K on two feet. It's goal-oriented, but generally a very positive and supportive community. Or even if you prefer to go solo (and not amass a bunch of cheesy race t-shirts) just setting goals like "I wanna run 20 minutes without stopping" can keep you really focused on staying with the program.