Yasso 800s. Say what?

I used to hate them, now I love them. No, not hill repeats, I still hate those, I’m talking about intervals.

For a couple of years I have been doing one intervals session a week, usually 5 x 1km with a minute walking break in between and about a 5 min warm-up and cool-down.

In the last 6 months I’ve been playing around with my Garmin’s workout functionality and been running 400s and 800s.

Today I did my first Yasso 800 session, a very specific kind of 800m intervals workout.

The theory behind Yasso 800s is that if you can run 10 intervals of 800m at 3:30 (with a 3:30 jog in between), you can run a 3:30 marathon. Or 4:30, or 4:00, or 2:30, etc. The first number being minutes and seconds, of course, and the second one hours and minutes.

I’m not running any marathons this year but I see no reason why my weekly intervals session can’t be the Yasso 800s – I like the idea of always being ready. Just in case an impromptu marathon pops up. You never know 😉

You’re advised to start with 4 intervals to begin with and add one every week. That’s if you use this kind of interval training in the 3 or so months before a marathon.

I did 5 today with the following times:

3:28
3:23
3:21
3:27
3:34

Since I’ve picked a nice round marathon goal time out of the air – 3:30 – the first split was spot on – 3:28 and pace of 4:21 min/km. To calculate these times/paces, use the Runner’s World calculator.

Second, third and fourth intervals were a bit too fast and the last one therefore too slow – 3:34.

I find it hard to look at the pace while sprinting, so in general I’m happy with the splits today. I will do 5 again next week and see if I can keep the pace steady at 3:28 or slightly faster. Then I will add one and see if I can keep the pace, etc. etc. etc.

Have you used Yasso 800s in your marathon training? Is it an accurate way of predicting a marathon time?