Running Yasso 800’s on a Bright Blue Track

He traveling with me needs the best blood, thews, endurance

— Walt Whitman, Song of the Open Road

As someone who loves to explore forest trails, I nonetheless spend a fair amount of time at the local track.  I’m always trying to run a little bit faster, and I love to make progress.

One of my favorite track workouts is called the Yasso 800.  It consists of ten 800-meter (or 1/2 mile) intervals, with 400-meter (1/4 mile) jogs for recovery in between.  The name was coined by Runners World editor Amby Burfoot in an 1994 article after he heard his colleague Bart Yasso claim that the drill would predict his marathon time.  It’s simple, Bart explained:  the average time for the 800-meter intervals in minutes and seconds would predict his marathon time in hours and minutes.  For example, an average interval time of 2 minutes 50 seconds would correspond to a marathon finishing time of 2 hours and 50 minutes.  The relationship could be thrown off by heat, wind, or hills, but the intervals had proven a reliable indicator, at least in Bart’s own experience.

Amby Burfoot claims to have interviewed one hundred runners and found the correlation held steady across a range of widely differing abilities.  He liked the Yasso 800s for their simplicity.  As he wrote in the 1994 article:

Anyone who has been running for a few years, and in particular trying to improve his or her marathon time, knows that training theory can get quite complex. You’ve got pace, you’ve got pulse, you’ve got max VO2, you’ve got lactate threshold, you’ve got cruise intervals, you’ve got tempo training, you’ve got enough gibberish to launch a new line of dictionaries.

Some people have questioned the theoretical validity of the Yasso 800s.  Others argue there are better ways to train for a marathon.  Nonetheless the Yasso 800s have become a popular drill for many runners — including myself.

As Bart explains in his memoirs, having a popular workout named after you is both a blessing and a curse.  The 800s don’t work miracles, after all, you still have to do long runs, hill workouts, and tempo runs.  And you have to do all ten intervals.  Bart recounts the story of a runner who thought he could run a single 800-meter interval (instead of ten) and use that time to predict his marathon performance:

He went out too fast, and crashed and burned. He blamed me for his poor finish. “They should be called the asshole 800s,” he told me, red-faced.

So come with me, and let’s go run the Yasso 800s, all ten of them.

It’s a beautiful day in late May.  The track where I run is a startling blue.


Warm-up starts at a slow trot.  The wind gusts out of the north.  I can feel my legs are still sore from a recent race, particularly in the left groin.  Taking these two factors into account, I back off my target pace by 5 seconds per mile.

The warm-up moves to short sprints that accelerate towards target pace.  As I pick up speed, I lean a little forward, my feet begin to kick up behind me, and I reach my knees another inch or two to widen the stride.  Glancing at my GPS watch, I see I’ve reached target pace and ease off.  It’s taken two and one-quarter miles to get ready just to start the Yasso 800s.

Starting is never easy!  Completing ten of these intervals is a daunting prospect, and from a standing start, it’s hard to wrap my head around the task.  Let’s say I could get three done — why then, I’d be half-way to six –which would just a little over half-way to the full ten and thus a good intermediate goal.  Of course, the second half will be tougher than the first, but I make a point not to think about that.

Besides the enormous effort, there’s also the risk of injury.  I must be mindful of this.


There’s nothing else to think about, and suddenly I’m off on the first 800-meter interval, accelerating on the first straight-away to a pace well below target.  I’m monitoring form, and everything feels good, even the sore groin muscle seems to have loosened up.  Now the first turn is upon me, and this brings me straight into the wind.  I lean forward a little more and put in extra effort, but exiting the turn, the watch shows me falling behind pace.  I reaccelerate into the straight-away and get back on plan.  On the next turn, I make a point not to look at the watch, remembering that its accuracy degrades around curves as it takes a reading only once per second, in effect cutting off some of the distance.

The track is 400 meters long, so I need to circle it twice to complete my first 800-meter interval, and now it’s time to catch my breath on a slow recovery lap.  If I can get a second interval done, I’d be one-third of the way to that intermediate goal of six.

The second intervals starts out quickly again, and this time I battle through the wind on pace.  However, the left hamstring feels a little sensitive.  I had strained this muscle last fall, and perhaps it’s just a residual ache.  If it develops into a problem, I’ll have to abort the workout.

The third intervals goes smoothly, as I sustain a steady effort, and on the fourth, I feel slightly triumphant, with the half-way point suddenly within reach.  A young college student is sunning herself on the side of the track.  On one lap she’s lying on her stomach, on the next, she’s rolled over on her back and talking on the phone.  The wind veers around to the west, flustering me on the straight-away, then it shifts back to the north.

For the fifth interval, I just want to sustain a steady pace.  The left hamstring continues to feel sensitive.  I’m checking my watch every few seconds.  As I get to the end of this interval, I’m breathing hard, but not yet fully depleted.  On the recovery jog, the hamstring feels a little heavy.

I’m on the sixth interval now and suddenly I’m thirsty.

On the seventh interval, I check my heart rate: it’s ranging from 168-170 beats per minute, or right at 100% of my age-based predicted max, and just about where it was last time I ran the Yasso 800s.  When I race a mile, my heart rate peaks at 174 beats per minute.

With three intervals left, I ought to be able to fight through to the end, no matter how deep the fatigue.  But the hamstring remains sensitive.  A group of joggers enters the track, bouncing along at a slow pace, talking, laughing.


The blue track passes beneath my feet.  Each lap follows the same pattern:  a fast start, the gusty headwind on the first turn, then the effort to stay steady.  I’m constantly checking the watch: if I’m drifting back, I put in more effort, if I’m ahead of pace, I dial it back.  My thoughts drift.  I look at the watch and see with alarm that I’ve slowed twenty seconds above target pace  — but it was only for a moment.

The joggers are sitting in the grass and stretching, chatting, smiling, and enjoying the sunny afternoon.  The watch flips back and forth, roughly +/- 5 seconds per mile around target pace.

It’s the last interval.  The joggers are gone.  I start out fast, leaning forward, feet striking on the outside edge, then kicking back, core muscles engaged, and then it’s into the turn and the wind and the straight-away.

That evening when I download the data from the watch, I find that the splits were very consistent, all within 2-4 seconds of target pace — and about 5 seconds faster than the last time I ran the Yasso 800s.

If I stick with this drill, I feel I could get a little bit faster.  Thanks Bart!

Maybe you’d like to try it?

yasso 800's

Heart rate (beats per minute) for 10 x 800 meter intervals, peaking at around 170 bpm


yasso pace
Pace in minutes per mile for 10 x 800 meter intervals


Running Yasso 800’s on a Bright Blue Track

4 thoughts on “Running Yasso 800’s on a Bright Blue Track

  1. Only once in my marathon training I did the Yasso. Didn’t feel it benefit me. Although I have been a slow 5k runner my marathons (when joints healthy) were around 4 hours. I felt that a weekly steady track workout helped, but not the Yasso. Mile repeats helped me more

    Liked by 1 person

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