I started training for the marathon properly in my early thirties. Went from about 3:15 shape in summer 2009 to my PB of 2:34 in October 2010. Did that on the sub 2:40 plan in Brad Hudson's book (not any of the plans in the end but the example plan in the middle of the volume). I'm now recovering from chronic health problems possibly due to overtraining. I'm not planning to run any marathons until late fall. Having never in my life trained for shorter distances I'm thinking I could reap more benefit from Daniels's r-pace workouts than someone with a background in 5k-10k. Any marathoners out there who have done these workouts? Did they help you a lot?