Most marathon runners have heard, at one point or another, the famous Yasso 800’s workout. It is presented usually as a predictor workout for a marathon. The workout itself is pretty simple: 10x800m where the 800m intervals (and subsequent rest intervals) are equal to your marathon finishing time.
Example: If your goal is to run a 3-hour marathon, you should be able to run each 800m interval in 3:00, with a rest/jog time of 3:00 also. Repeat 10x and you’re ready for that marathon. Nice and neat, BUT..
I think Yasso 800’s are a poor predictor. And here’s why!
TOO AMBITIOUS
I remember years past where I could just crush this workout. 2:45, 2:40, 2:30’s, some even lower. But my marathon fitness was nowhere close to those times (and races showed it!). I’ve heard from others too that have said it predicts just way too fast! Relying on this too much may cause you to set out too fast in a marathon and suffer for it.
NOT SPECIFIC ENOUGH
Usually, race predictor workouts involve running at the pace of the race. And it will stress you in a way similar to the race. Running some fast 800’s will not do either of those things.
TOO MUCH REST
The pace of Yasso 800’s lines up with a VO2 max workout but I think it’s just too much rest between intervals to give a good endurance stimulus. I’d rather subtract about a minute from it (so 3 minutes on, 2 minutes off in my example). Even then though, that still just makes Yasso 800’s a solid VO2 Max workout, not a race predictor.
DO THIS INSTEAD
Use a long run effort that includes marathon pace in it towards the end. How does the pace feel at the end of it? Do you feel like you could continue for X miles? I can literally still FEEL some of these workouts from past cycles because they instilled so much confidence!
In Bart Yasso’s defense, I believe he said he never intended the 800’s to be a tried and true predictor. It seems closer to a VO2 max work out with extended rest which may work for you depending on the rest of your training. Just please stop using it as a predictor!
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