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Yasso 800s

What are Yasso 800s?

Definition of Yasso 800s
Yasso 800s are a specific speed workout that can predict your marathon finish time. Developed by Bart Yasso, Chief Running Officer of Runner’s World, Yasso 800s are run on a track. Specifically, they’re 800m (1/2 mile) repeats.

For the workout, you run 10x 800m at a pace “equal” to your goal marathon finish time. Say you want to run a 3:40 marathon, your Yasso 800 pace would be 3 minutes and 40 seconds per 800m repeat. If you can hold that pace for 10 Yasso 800s, you can theoretically run a 3:40 marathon (assuming you do your long runs and follow a marathon training plan). In between each Yasso 800, recover by jogging for the same amount of time each 800 repeat takes – in our example that would be 3 minutes and 40 seconds.

When to do Yasso 800s
Some marathon training plans call for Yasso 800s every few weeks or so. Bart Yasso himself does them every week of marathon training. The first week, he starts with four Yasso 800s, the next week he does five, the following week he does six, until he works his way up to 10 Yasso 800s. He then does 10 repeats for the rest of training. Yasso says the last Yasso 800 workout should be at least 10 days before your marathon, but ideally 14- 17 days prior.

Pace goals of Yasso 800s
The pace of Yasso 800s coincides directly with your marathon goal pace. However, many training plans don’t call for Yasso 800s. Instead, they may call for other speed interval workouts.

Training method Recommendations
Hal Higdon Higdon’s marathon advanced marathon training plans call for Yasso 800s every 3 weeks.
Jeff Galloway Galloway’s plan does not call for Yasso 800s or any speed workouts.
FIRST The FIRST program doesn’t include Yasso 800s. Rather, FIRST requires speed repeats of 400m, 800m, 1200m, and 1600m throughout training. The 800m repeats are run at 10k pace minus 45- 50 seconds.
Hanson method The Hanson method doesn’t include Yasso 800s. The Hanson method says speed intervals should last between 2- 8 minutes each and should be run at 80- 95% of VO2 max.
Pete Pfitzinger Pfitzinger’s marathon training plan doesn’t include Yasso 800s. Instead, he calls for intervals done close to VO2 max or 5K pace.
Jack Daniels Daniels’ plans don’t specifically mention Yasso 800s, but they call for interval runs at 98- 100% of maximum heart rate.
Greg McMillan McMillan says Yasso 800s are an excellent predictor of your marathon finish time, but plus 5 minutes. So, if you can run 10 Yasso 800s at a 3:20 pace, your marathon time will be closer to 3:25. He recommends doing 2-3 Yasso 800s workouts during marathon training.

Yasso 800s in a nutshell
Yasso 800s are for experienced runners with a specific marathon time goal. Doing these repeats throughout training can help determine if your marathon goal is realistic or not. If you’re a beginner running your first marathon, Yasso 800s likely aren’t for you.

RELATED: Check out our full series on the different types of runs

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Written by Jen Matz.