McMillan Custom Marathon Plan: Week 12 Day 4

Ah, tough workout tonight and I wasn’t sure how my sore shin would hold up. Luckily it turned out to be ok (although I’m not sure what I’ll wake up to tomorrow morning….)

After an almost 30 minute warm up, it was time to perform one of favorite track workouts; the Yasso 800s. For those who’ve never tried them they are a great marathon prediction workout pioneered by Bart Yasso.

From the McMillan Running web site:

The theory behind Yasso 800s is that your time in minutes and seconds for a workout of 10 times 800 meters (two laps of the track) with equal recovery time is the same as the hours and minutes of your marathon time. For example, if you can run 10 times 800 meters in three minutes and 20 seconds with three minutes and 20 seconds recovery, then this predicts that you can run three hours and 20 minutes for your marathon. Run 2:40 for the 800s and you can run 2:40 for the marathon.

My experience, though, is that Yasso 800s predicts about five minutes too fast for most marathoners. Using the example above, my experience has been that 10 times 800 meters in 3:20 with 3:20 recovery yields closer to a 3:25 marathon for most competitive runners. Because this workout is easy to do, I try to include it two or three times in a marathon training cycle. It not only provides a good predictor of marathon pace but allows you to chart your increasing fitness – a big confidence builder.

I’ve tried the Yasso 800s several times in the past, but never this far in advance of a marathon. From what I recall, the Yasso’s were a fair indicator of my marathon finish time so I was interested to see what I could run tonight.

Track work for me is always a struggle. I never feel totally fluid on the track and always seem to be lumbering along rather than gliding down the back straight. Oh well, it’s all for a good cause so off I went for Yasso #1 which I completed in a surprising 2:48; not too bad at all.

After an equal recovery time in which I jogged about 500m, I took off on #2. This one was a bit more difficult but I managed another 2:48. The wind appeared to kick up a notch or two (perfect timing), but I stayed positive and after a 500m recovery jog accelerated into #3. Somehow I managed to run the third 800m slightly faster in 2:47, but by now I was thirsty and breathing hard.

Next time I’m due to do a track workout, please remind me to take a water bottle. It seems every time I convince myself I’ll be fine, but half way through the workout I’m gasping for a drink. I guess I’ll never learn.

Anyway, on to #4 and in the back of my mind I expected to slow to a 2:49 or possibly a 2:50. My shins weren’t really bothering me, but my legs were slightly fatigued. Again I surprised myself with an even quicker 2:46 and reminded myself there were only 2 more 800s left to run.

500m later and still breathing hard, I took off for #5. I wanted to maintain the same pace but also wanted to save a bit for the last interval. My time at the 400m mark was 1:23 and with a little extra effort I matched the first lap and finished with another 2:46.

This time I treated myself to a 30 second walk before starting a slow jog before the final 800m. My mouth was so dry and legs heavy, but I gave it my all for 2 laps and crossed the line in 2:44; the fastest interval of the night to give me an average 2:46.5 for the 6 Yasso’s.

Not sure how good a marathon predictor this workout will turn out to be, but with 8 weeks still go I’ll be looking for an improvement next time I run it. Looking back through my running logs it appears that this is my best group of 800m repeats I’ve ever done, so naturally I’m very pleased and hoping my legs feel good tomorrow morning. We’ll see….

For the record:

Distance: 10 miles
Time: 1:11:00
Pace: 7:06 per mile