Yasso 800s is a popular speed workout for distance runners, named after its creator, Bart Yasso, the former Chief Running Officer at Runner’s World. The workout consists of running 800-meter intervals at a pace that corresponds to a runner's goal marathon time. For example, if a runner's goal is to complete a marathon in 3 hours, they would aim to complete the 800-meter repeats in 3 minutes.

The workout is typically performed as 10 x 800m repeats, with a recovery jog between each interval. Yasso 800s are often used as a benchmark workout to improve speed-endurance and as a simple, yet challenging, speed workout for marathoners and other distance runners. While Yasso 800s are a popular workout, some coaches and experts caution that it may not accurately predict marathon finishing times and that it is not a specific marathon fitness workout. Therefore, it is important to use Yasso 800s as part of a well-rounded training plan and not rely solely on this workout for marathon preparation.

Yasso 800s is a workout method that helps runners estimate their marathon time. Created by Bart Yasso from Runner's World magazine, it involves running 800-meter intervals at a specific pace. The time it takes you to run these intervals is thought to roughly predict your marathon finishing time in hours and minutes.


  1. Workout Structure: Start with a warm-up jog of 1-2 miles, then do a few strides. After that, run 4-10 intervals of 800 meters each, based on your fitness level. Between each interval, take a recovery jog.
  2. Pace Calculation: Your pace for each 800-meter interval should match your target marathon time. For instance, if you aim to finish a marathon in 4 hours, try to run each 800-meter interval in 4 minutes.
  3. Benefits: This workout can boost your endurance and speed. It's also useful for getting an idea of your potential marathon time.
  4. Limitations: Remember, Yasso 800s isn't perfect. Your actual marathon time can be influenced by various factors like weather, the course's elevation, and your nutrition strategy.

In summary, Yasso 800s is a helpful workout for runners training for a marathon. It assists in improving speed and endurance and gives a rough estimate of your marathon finishing time. However, it's important to consider other aspects of marathon preparation for the best performance.


The purpose of Yasso 800s in marathon training is to improve speed-endurance, enhance the body's ability to perform at goal marathon pace, and provide a benchmark for tracking progress. This workout involves running 10 x 800-meter intervals at a pace that corresponds to a runner's goal marathon time. The benefits of incorporating Yasso 800s into marathon training include:

  1. Speed-endurance: Yasso 800s help improve the body's ability to maintain a steady pace over long distances, which is crucial for marathon running.
  2. Pace Management: The workout helps runners experience the demands of marathon pace, allowing them to better manage their pace during the actual race.
  3. Benchmarking: Yasso 800s can serve as a benchmark workout to track progress over time, providing valuable insights into the runner's improvement and fitness level.
  4. Simplicity: The workout's simplicity makes it an easy-to-follow option for runners, who can perform it regularly to improve their running speed and endurance.

However, it is essential to note that Yasso 800s may not accurately predict marathon finishing times, and they do not specifically target the demands of marathon racing. Therefore, Yasso 800s should be used as part of a well-rounded training plan, complementing other marathon-specific workouts and long runs.