I am usually pretty good about conducting thorough research on a new pursuit before diving headlong into it, but when I set out to train for a marathon I did so without looking into how to properly train. This was a mistake, as I wasted many miles on workouts that were not at all beneficial for the distance I was preparing to run. Since I had run cross-country way back in high school, I figured the workouts I had done in preparation for the 5,000-meter races would be more than sufficient if I only slightly modified the distances and effort. I was wrong.
I knew that volume was one of the most important considerations in a marathon training program, and I was able to quickly move up to 60 and 70 miles per week after about six months of dedicated training. While I was increasing the volume, I was also doing speed sessions on the track that were completely unnecessary and probably had a negative effect on my efforts on race day.
I completed my first marathon without much trouble, but I did not run the time that I thought I was capable of. This is when I started to look a bit more deeply into marathon training and realized that I could train for this distance much more efficiently by ditching the speed sessions in exchange for anaerobic threshold (AT) runs. Training this way I was able to bring my volume up to 80 to 90 miles per week and felt good enough to include a number of 18- and 20-mile long runs before race day. This simple change allowed me to PR by a wide margin over my previous time in the marathon, and I even ran the half-marathon splits faster than I had ever run the distance before.