I'm a fairly successful 1500m-5k runner interested in moving up to the 10k to half marathon since most of the best road races fall into that range. In the past I've run about 80 MPW in the preseason and 50-70 MPW during the racing season. My workouts in the preseason have included uptempo runs of 4-5 miles, 1k repeats at 3k-5k pace, and 200-400s at 1500m pace. My 5k PR is WAY better than my 10k, but I'd really like to give longer distances a shot. Anyone have any tips? How much should I increase my mileage? What kinds of workouts should I start doing? Is there anything I should stop doing? Thanks.