Best Running Tips :: Yasso 800

Special Workout : Yasso 800

Named after a Runner's World editor, this workout, the Yasso 800, gained quite a bit of popularity over the last few years.

So, how do you do this workout ?

During your marathon training you build up your 800 metre-repeats every week (from about four to ten).
Your goal is to run these 800 metre-repeats at a constant pace.

The time you spend running these 800 metres in minutes, is a prediction of how fast you can run your marathon in hours.

So, say you do your Yasso 800s at 3:30 min / 800 metres.
In between you recovery jog for the same amount of time (so 3:30 min).
Then your predicted marathon time is 3:30 hours.

Doing your 800 metre-repeats at 2:50 min / 800 metres (recovery jog for 2:50 min). Then your predicted marathon time is 2 hours and 50 minutes.

Almost too good to be true...
And yes, it often is.
I will explain why.
It is still a good workout though, so I will explain to you how to use it.

Why are Yasso 800s not very good at predicting your marathon time ?

Think about it. 800 metres compared to 26.2 miles.
A marathon is about 53 times more than 800 metres.
The difference is simply too big.
Even 10K's and half marathons are no good at predicting your marathon performance if you do not properly prepare for the marathon.
The marathon requires a sufficiently developed aerobic base.
An 800 metre is mostly anaerobic.
You can't expect an anaerobic training result to be indicative of your aerobic running race !

You will find that using these 800 metre-repeats as a predictor, you will often not reach your marathon goal time, but you will be ten to fifteen minutes slower.
There is simply a lot more involved in running a three hour marathon than being able to run ten 800 metre-repeats in three minutes.
It's nice. It's gimmicky. But unfortunately it's not that simple.

Is there no value in the Yasso 800 as a predictor ?

In several forum discussions I have seen runners claiming that the Yasso 800s do predict your marathon time if during all 800 metre repeats your heart rate stays at the same level.
If it creeps up during the workout you will probably not be able to run your race at the predicted time.
I have not tried this out myself.

Another possibility I see is using this workout as a predictor of half marathon performance.
What do you need to do ?

Decide on your goal for your half marathon race

Find the equivalent marathon time using this race conversion calculator filling in your half marathon time as "the race you ran" and work out the corresponding marathon time.

Then use this time in hours to deduct the time in minutes of your Yasso 800s

An example to try out with the race conversion calculator if it is unclear :

Want to run a half marathon time of 1:35 ?

The equivalent marathon time is 3:18:04

So, your Yasso 800s should be 3:18 mins in length.

Are Yasso 800s a good workout ?

Yes, quite so. There is nothing wrong with doing 800 metre-repeats. But studies have shown that the optimal interval lasts for about five minutes.
Most runners can go quite a bit further than 800 metres in five minutes.
So, 800 metre-repeats are generally too short.
But, I still like to do them occassionally.
At least if I am at a track.
I have done them "in the wild" as well.
But the obvious problem is then to get an exact 800 metre run done. Every time. So your in-between recovery jog needs to be finishing at the exact right spot at the exact right time.
And that's just a bit too inconvenient.

So, I normally stick to running my intervals based on time and quite a bit further than 800 metres.

But that's me. Feel free to use Yasso 800s as an interval workout.
But be a bit careful with using the Yasso 800 as a lead indicator of marathon performance. And with dedicating a good chunk of your marathon preparation time to this particular workout.

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