Alex Yee completes Yasso 800s with average 2:14

Doing some track intervals during marathon training is a great way to break up the boredom of endless training. As someone who didn’t grow up running I looked forward to the track. I liked running a little bit faster for the variety. Yassos are probably more likely a negative predictor. If you can’t meet your arbitrary target doing them you aren’t likely to run that marathon time.

I didn't mean being in 800/1500 shape and doing the Yasso 800s.

But if you were an 800/1500 athlete, the odds are you're speedier than most marathoners. The odds are you're naturally anaerobically strong. The odds are that you gravitate towards that type of work. When I did marathon training after being a middle distance runner, I lost some speed. But I was still way faster than most and I still would have way overperformed on these 800s vs reality, due to my speed and anaerobic strength.

+/-5% is a lousy predictor.

They don't. I did this magic Yasso workout a few times long ago in buildups and found I could run the 800s, as prescribed, far faster than I could run a marathon, like 20 seconds per rep. (With the last few fastest.) But I'm more of a fast-twitch runner, so I like track workouts. 800s are nothing compared to an 18-miler. The fact that I could run the 800s fast was, in fact, not a great sign for a marathon; I still had too much 'speed' in my legs.

It's basically a 10k specific workout, so why would it be any better at predicting his marathon time than his 10k best?

I'd argue it's much worse, because effective training is not all-out, and so it's very easy for people to manipulate the session by running it too hard. At least with a 10k race we know it was all-out.

Skuj 100s - is that where you run 50 x 100 without a recovery?

That's a very accurate predictor session. The most bigliest accurate predictor.

Why would you divide the number of 800s in a marathon by the number of minutes in an hour?

Just a few examples to illustrate this:

-2:10 average -> 2:10 marathon but 5% range = 2:03:30-2:16:30

-3:00 average -> 3:00 marathon but 5% range = 2:51-3:09

-4:00 average -> 4:00 marathon but 5% range = 3:48-4:12

If you think you are a halfway decent coach and you can’t tell if your runner is in 2:04 or 2:16 shape maybe you are actually just a Runfluencer.

Exactly this. Using VDOT charts/calculators, your time for an 800 run at 5k pace expressed in minutes:seconds is roughly (and coincidentally) your VDOT equivalent marathon finishing time expressed in hours:minutes.

Don't hate Bart Yasso for noticing the coincidence between his 10×800s and his Marathon fitness.

2:14 would be a disappointing result for him

Yasso 800s are not a marathon predictor. Bart Yasso even says this himself. He just noticed a loose correlation between the times. They're also not a great marathon workout.

What? where are you pulling this from. And +/- 5% for a 2:15 would mean a range of 2:08-2:22. How can that be considered at all accurate.

It works a little in figuring out how much latent "speed" a runner has. Runner A runs 60 miles a week and his easy pace is 7:30 but he is a former track runner very comfortable at much faster paces. So he does the Yassos in 2:50. Runner B runs 60 miles and his easy pace is 7:30 but he never ran track and never really runs below 6:00 pace. He does the Yassos in 3:05. "Hobby Joggers" often struggle to run at faster paces beause they never do it.

I ran 2:18:59 (5:18/mi) at CIM last year, yet 10×800m at 2:19 would be impossible for me. That's sub 4:40/mi for 8k of work, meanwhile my 5k pace is still 4:50/mi.

I rarely did intervals shorter than 1000m in the months prior to my marathon PB, & rarely dipped under 5:00/mi, except for hills sprints & strides. Some people are just built different, I can maintain pace very close to my threshold (roughly 5:05) for the marathon, yet as soon as I get under 4:50 pace, my muscles tighten immensely & can't push any faster. This may be due to the heavy mileage I was enduring.

Point is, I would've been lucky to do 10×800m any faster than 2:25 during the peak of my training block, yet still easily broke 2:20 for the marathon.

Alex Yee could likely break 2:10 or faster if he has a similar physiology to me. (Very light & efficient)

It's not that marathon training makes it hard for trained marathoners to rip 800s at VO2 max pace.

It's that a LACK of marathon training means most weekend warriors can't run a marathon remotely in keeping with what their VO2 max would predict.

They don't.

Pretty much any high school runner can do 8x800 at 3:00 on equal rest. That is 18:45 5k pace.

Meanwhile, a small fraction of these runners could even finish a marathon, let alone break 3:00.

Good post.

8x800 aiming for the fastest possible times, on equal time rest, is quite obviously a VO2 max paced workout.

That is, a runner's performance in this will be determined primarily by the VO2 max, with smaller roles for pure speed, lactate threshold, aerobic threshold, and muscular/biomechanical endurance.

A marathon performance relies much less on VO2 max, and much more heavily on LT, AT, etc.

Essentially, for most runners who aren't aerobic monsters (i.e. those coming up from shorter distances), Yasso 800s say something predict their marathon CEILING: what they can achieve if they optimize other fitness elements in line with the VO2 max that it actually reflects.

Good post.^

You don't seem to understand the conversation.

Nobody is saying that Yasso 800s are run AT YOUR MARATHON PACE. 😆😆😆

8x800 with 2:30 rest would be a decent workout at 5k pace. (Probably a better predictor of that than it is of marathon pace, in fact.)

Marathon pace for a decently balanced runner is, very roughly, 45 seconds slower than 5k pace per mile.

If you were in shape to run a 5k at 5:00/mile pace, ~15:30, then a reasonable expected marathon pace for you would be about 5:45/mile, or ~2:30 for the distance.

As a mid-distance runner, it's normal that it would be a reach for you to run a marathon as high quality as your 5k pace / VO2 max / Yassos would suggest.

themorningshakeout.com

Workout of the Week: Yasso 800s - the morning shakeout

Mario Fraioli

Yasso 800s are perhaps the most well-known speed workout amongst dedicated marathoners of all levels. The premise is pretty straightforward: If your goal is to run a marathon in, say, 3 hours flat, you should be able to do te...

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"The premise is pretty straightforward: If your goal is to run a marathon in, say, 3 hours flat, you should be able to do ten 800m repeats in 3:00 with a 400m jog for recovery between reps. A 2:45 marathoner would run their reps in 2:45, and so on and so forth. No doubt, running 10 x 800m in a split that corresponds with your goal marathon time—which actually works out to around your 5K pace, according to the Jack Daniels VDOT calculator—is a challenging workout, but it doesn’t actually tell you anything about your ability to run goal pace for a marathon. It’s simply a good workout."