Browsing the sneaker rack was always a struggle. Inevitably I would exaggerate to the sales assistant, advertise myself as a competitive runner and opt for the high-impact, cushioning, running shoes. Mentally, I pictured myself as a runner who hit the pavement a few times a week; while physically, I never attempted more than a 5K race (and even that was almost two years ago). I have a shirt to prove it.

Blame it on the chronic shin splints and flat feet, running just wasn't my sport—and that's what made it all the more attractive. Employing the same "I can do anything better than you" mentality that got me through CrossFit training, I became determined (obsessed) with finally putting my high-end sneakers to use and decided to become a (half) marathoner in 12 weeks. Here are the tricks no one told me about.