What are Yasso 800s?
Yasso 800s are one of the best-known marathon workouts in the world. They were popularised in Runner’s World in 1994 by Bart Yasso, the magazine’s long-time “Chief Running Officer”, who noticed a curious pattern in his own training: the time in minutes and seconds he could hold for a set of 800 m repeats matched his marathon time in hours and minutes.
Example: a 3:45 marathon goal → 800 m repeats in 3 minutes 45 seconds
Recovery: jog for the same time as each repeat
Yasso 800s chart
800 m targets for common marathon goals, with the per-lap split on a 400 m track and the pace per km the repeats represent. Compare that with actual marathon pace to see how much faster the workout is.
| Marathon goal | 800 m time | 400 m lap | Repeat pace /km | Marathon pace /km |
|---|---|---|---|---|
| 2:30 | 2:30 | 1:15 | 3:08 | 3:33 |
| 2:45 | 2:45 | 1:22 | 3:26 | 3:55 |
| 3:00 | 3:00 | 1:30 | 3:45 | 4:16 |
| 3:15 | 3:15 | 1:38 | 4:04 | 4:37 |
| 3:30 | 3:30 | 1:45 | 4:22 | 4:59 |
| 3:45 | 3:45 | 1:52 | 4:41 | 5:20 |
| 4:00 | 4:00 | 2:00 | 5:00 | 5:41 |
| 4:15 | 4:15 | 2:08 | 5:19 | 6:03 |
| 4:30 | 4:30 | 2:15 | 5:38 | 6:24 |
| 4:45 | 4:45 | 2:22 | 5:56 | 6:45 |
| 5:00 | 5:00 | 2:30 | 6:15 | 7:07 |
| 5:15 | 5:15 | 2:38 | 6:34 | 7:28 |
| 5:30 | 5:30 | 2:45 | 6:52 | 7:49 |
| 5:45 | 5:45 | 2:52 | 7:11 | 8:11 |
| 6:00 | 6:00 | 3:00 | 7:30 | 8:32 |
Goal links open our full pace chart for that marathon time where one exists.
How to run Yasso 800s
- Warm up with 10–15 minutes of easy running and a few strides.
- Run 800 m (two laps of a track) at your target time.
- Jog for the same amount of time to recover — 3:45 of jogging after a 3:45 rep.
- Repeat. Start with 4 reps about 10 weeks out and add one each week, reaching 10 reps roughly 10–14 days before race day.
- Cool down with 10 minutes of easy running.
Do Yasso 800s actually predict your marathon?
Honestly — not very well. The rule has never been validated in a scientific study, and it relies heavily on anecdote. The repeats are run well faster than marathon pace (often around 5K pace), so they mostly test your speed and VO2max. The marathon, on the other hand, is decided by endurance, long runs, fuelling and pacing.
A useful sanity check: 800 m repeats in 3:45 are 4:41 per km — close to the 5K race pace of a runner who races around 23 minutes. The race time predictor puts a 23:15 5K at roughly a 3:42 marathon if endurance matches speed — so for this runner the Yasso rule happens to land close. But many runners with the speed and without enough long runs and weekly mileage end up well slower on the day.
Use them as a workout, not a crystal ball. Yasso 800s are an excellent, time-efficient interval session. Confirm your marathon goal with a half-marathon race about 4–6 weeks out, then set race pace with the marathon pace calculator.
Variations
Shorter recovery
Advanced runners sometimes cut the jog recovery to half the rep time to make the session more marathon-specific.
Treadmill Yassos
Set the treadmill to 1 % incline and run 800 m at the matching speed; see the treadmill pace calculator.
Magic Mile
Jeff Galloway’s single-mile time trial is another quick predictor — try the Magic Mile calculator.
Last reviewed: September 2026 · Health disclaimer