How it works
800 m target = marathon goal time ÷ 60
The Yasso rule maps your marathon goal of H hours and MM minutes onto an 800 m repeat of MM minutes and SS seconds — in other words, divide your marathon time by 60 to get the 800 m time. A 3:30:00 marathon (12 600 seconds) becomes a 3:30 (210-second) 800; a 4:00:00 marathon becomes a 4:00 800. The pace figures come from that 800 time over 0.8 km. In training you build up to running ten of these 800s in one session with an equal-time jog recovery between them; if you can complete that workout at your target time a few weeks out, it is a strong sign your marathon goal is realistic.
Sources
- Yasso 800s Bart Yasso, Runner’s World — the Yasso 800s workout: 800 m repeats whose min:sec match the marathon goal’s hours:minutes.
- Interval training basis Repeat 800 m intervals at goal-derived pace develop the aerobic power and pacing needed for the marathon; the rule is a practical heuristic, not a physiological model.
- Recovery convention The classic protocol uses a jog recovery of equal duration to each 800 m repeat.
FAQ
What are Yasso 800s?
A marathon-prediction workout of repeat 800 m intervals. Bart Yasso noticed that the time runners could average for 800s — in minutes and seconds — tended to match their marathon finish in hours and minutes. So a goal of 3:30 marathon means running your 800s in 3:30.
How do I do the workout?
On a track, run 800 m (two laps) at your target time, then jog for the same amount of time to recover, and repeat. Build up over several weeks from 4–6 repeats to a peak session of 10 × 800, ideally completed two to three weeks before your marathon.
How accurate is the Yasso prediction?
It is a rule of thumb, not a precise formula. Many runners find it lands within a few minutes of their actual marathon when their endurance base is solid, but it tends to be optimistic if your long-run training is weak. Use it as a confidence check alongside a proper race-time predictor.
What recovery should I take between repeats?
The traditional protocol is a jog recovery equal in time to the repeat — so if you run a 3:30 800, you jog for about 3:30 before the next one. Keep the recovery easy; the goal is to complete all ten repeats at the target time, not to make the recovery hard.
Can I use Yasso 800s to set a marathon goal?
Yes — work backwards. Run a hard set of 800s, take your realistic average time, and multiply by 60 to estimate a marathon time. Combine it with your long-run fitness and a race-time predictor before committing to a goal pace.
Are Yasso 800s enough marathon training on their own?
No. They are one quality session in a balanced plan that also needs easy mileage and long runs to build endurance and fuelling. The workout sharpens speed and confirms fitness, but marathons are won on the aerobic base behind it.
The Yasso 800 rule is a popular heuristic, not a guaranteed predictor. Actual marathon performance depends on endurance, fuelling, pacing and conditions. General information for training, not medical or coaching advice.