c25k is fine for running, but it can be very inaccurate if you go based on time (since, you know, everyone runs at different speeds). So, for example, if you're a fatass and run for 20 min you could only cover a mile, whereas fit people would cover 2 (at least). So it's easy to cheat by saying "I ran 20 min" as opposed to "I ran 2 miles" if you're an obeast.