The problem with running 30-45 seconds/mile slower than our standard race pace is it’s still too close to the lactate inflection point. We’re cutting ourselves short on key aerobic adaptations. The majority of marathon training should be done around 80% of your predicted marathon race pace (or for half-marathon training, 25-30% of your half marathon race pace). That’s about 2-2.5 minutes slower per mile than you expect to race in a marathon. Towards the end of the training cycle is when you can add speedwork sessions to build efficiency at race pace. To estimate your own training paces, try the McMillan calculator.
It’s counter-intuitive, so it made a big difference for me to learn the science behind training this way. It definitely makes sense for the marathon. However for half marathon training, I can’t imagine doing my “long runs” at 8:45-9:00/mile pace when my half-mary race pace is about 7:20/mile. Then again, the length of my weekly “long runs” will need to increase significantly as well to 14 or 15 miles. Right now I top out at about 10.
Upon further review, my current half-marathon training strategy is probably most in line with 10K racing. Not coincidentally, that happens to be the distance I’ve recently performed the best at according to the age-grading calculators (70%)
It’s time to evolve beyond from my haphazard ways. Thanks to the extreme heat and humidity of summer in Hotlanta, I’m treating the upcoming months as my off season. It’ll give me a chance to test out the long, slow distance thing. I make my own best guinea pig. Hopefully I’ll approach the fall with fresher, stronger legs ready to be fine tuned for the demands of shorter races. We’ll see how things turn out over the next few months. I’ll continue to do the race/weight correlation for you too.
It's easy to tell other people how to do things, but it's quite different trying to put it into practice for myself. I counting on y’all to help keep me in line.