How to Do Yasso 800s

Use this workout to achieve your marathon goal time

Black woman running on track

Adam Hester / Getty Images

Yasso 800s are a popular workout among runners who are trying to achieve a specific marathon goal, such as trying to qualify for the Boston Marathon. The name "Yasso" comes from Bart Yasso, the former chief running officer at Runner's World magazine, who popularized this workout. It is a training regimen based on running multiple intervals of 800 meters.


The premise behind Yasso 800s is that running a series of 10 fast 800-meter intervals alternated with short rest periods will approximate the effort and speed of running a marathon at your target pace. This training protocol aims to help you develop speed, pace, and endurance.

Yasso 800s are best done on a track because it makes it easy to measure 800 meters, which is a distance of two laps on most standard tracks or approximately one-half mile. You could also do them on a treadmill since you'll know exactly how far and fast you're running.

You can run Yasso 800s anywhere, as long as you have a way to measure the distance and time you run.

How to Do Yasso 800s

You first need to know your marathon goal time in hours and minutes. Then, convert this time to minutes and seconds. For example, if your marathon goal is 3 hours and 30 minutes, your converted time is 3 minutes and 30 seconds. Once you have your time, follow the below training schedule:

  • Warm-up: First, do an easy warm-up of 5 to 10 minutes jogging and a few warm-up exercises.
  • 800-meter interval: Try to run 800 meters (approximately 1/2 mile) at your converted time (3:30 in this example).
  • Recovery: Jog or walk for the same amount of time (again, 3:30 in this example).
  • Repeat: Start with three or four repetitions per workout in the first week. Later, you will add more.
  • Cooldown: Finish your workout with 5 minutes of easy running or walking, followed by stretching.

For runners with a marathon time of 5 hours or more, 5 to 6 minutes of rest time between 800s is not recommended. This is too much recovery and will take a long time to complete. Instead, give yourself 3 to 4 minutes to jog between intervals.

Add Repeats

Continue with Yasso 800s workouts once a week. Aim to add one more repetition each week until you reach 10 repetitions per training session. The first few should feel pretty easy, and you may run under your goal time. However, as you add repeats, you'll notice that each interval starts to get more challenging, and you may have difficulty hitting your times.

If you're unable to hit your goal time (or faster) on your last repeat, stick to that number of repeats in the following weeks until you're able to complete all repetitions at your goal time. If you're having a hard time progressing past your goal time after a few repeats, you may want to reconsider whether your target time is a realistic goal for you.

Don't Overdo It

Don't make the mistake of assuming that doing Yasso 800s more frequently will increase your chances of hitting your goal time. Make sure you're slowly building up your repetitions and only do the workout once a week. More than once a week will be counterproductive. Not giving your body a chance to rest and rebuild can negate some of the effects of your hard work.

As with many speed workouts, overdoing it can increase your risk of injury.

Stick to Your Training Schedule

In addition to weekly Yasso 800s, you'll still want to do your regular marathon training, including weekly long runs. Additionally, even with the proper training, being able to complete 10 Yasso repetitions doesn't guarantee that you'll finish the marathon in your goal time—but it will give you a good shot at hitting your target.

A Word From Verywell

Your finishing time will depend on many factors, such as training, course terrain, and weather conditions. However, if you can't complete the 10 repetitions, it's probably a good indication that you're unlikely to hit your goal time. If that's the case, simply add a bit more time to your goal until you find the sweet spot—challenging but not unattainable—that's right for you.

1 Source
Verywell Fit uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Kreher JB, Schwartz JB. Overtraining syndrome. Sports Health. 2012;4(2):128-138. doi:10.1177/1941738111434406.

By Christine Luff, ACE-CPT
Christine Many Luff is a personal trainer, fitness nutrition specialist, and Road Runners Club of America Certified Coach.