Today I did a complete set of ten Yasso 800s.
I started with an easy mile warm up, then did 800 meter intervals at a perceived fast pace with 400 meter slower intervals in between. I didn’t try to check my speed while I was running, I just ran hard enough to be breathing heavily throughout the intervals. I wouldn’t wanted to have had to try to talk! Typically Yasso 800s are done on a track, but I did mine in my neighborhood which includes some elevation changes — nothing drastic or long but definitely not track flat.
Yasso 800s are considered one good way to include speed work in weekly training runs — usually once a week or so. I haven’t been doing them before this because I was focused on increasing my overall mileage and endurance. But my legs felt really good today to start the week — I must be getting used to 50+ mile weeks! And I was curious to see how I would do because Yasso 800s are often considered a predictor of marathon finishing time (see this Runner’s World article). The idea is to take the average time of your 800 splits and read the minutes and seconds as predicting your hours and minutes for a marathon finish. Some say this method under estimates your finish time and suggest adding about 5 minutes.
So, how did I do? Surprisingly well considering that I haven’t been doing any speed work and I didn’t do these on a flat track. I averaged 4:18.31. Even adding 5 minutes to account for under estimation and another 5 minutes in case I need to make a porta potty stop, it confirms my conviction that I should be able to finish somewhere around a 4:30 time if conditions are nominal on race day.
This is my last 50+ week of training with a 20+ mile run coming up on Saturday. After that, I’ll be dialing back the total miles just a little each week, but I do hope to continue doing some speed work and more hill running over the next 3 weeks. I just wish the Philadelphia Marathon was this coming weekend. I am so ready to run it now!