So I ran in the cowtown half with basically no training. I've been doing about 3-4 runs a week since November, maybe 10-20 miles a week. I signed up for the half two weeks before on a whim. I did two eight mile runs that week and then took the next week off because I was stressed with work. I ran 1:36:12 with a bathroom break and feet/calves cramping from mile nine on. The result was a giant surprise since I have a history of giving up on races half way through and slowing down. My question for the great minds of letsrun: based of a mid twenties female with little training, how long and what kind of training would I have to do to drop my time in to the 1:20s?