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2008 Boston Marathon Prep – 4 Weeks Out – Key Workout #2

Thursday morning was my second key workout of the week and it involved Yasso 800s on the treadmill. Yasso’s are one of the marathon predictor workouts that let you know if you don’t have the current fitness for your goal pace. The workout involves a set of 800m intervals completed at your marathon finish time in minutes/seconds versus hours/minutes. Ok, this is a bit confusing, let’s look at an example.

  • Desired marathon pace: 8:00 min/mile = 3:29:45 marathon finish time
  • Each 800 m interval would be completed at approximately 3 minutes and 30 seconds or at a 7 min/mile pace.
  • Recover for approximately 400m or 3 minutes and 30 seconds.
  • Repeat interval for a total of 10 sets.
  • If you are able to complete the 10 sets you may have the necessary fitness to complete your marathon at your desired pace. It is not a guarantee but does signify your goal is within reach.

I have never done this kind of workout before so I thought I would give it a try. Ignorance is bliss. Little did I know what I was getting myself into.

So my workout looked like the following:

  • My WAG finish time: 3:00 = 6:52 min/mile pace
  • Each 800m interval completed within 3 minutes at 6 min/mile pace.
  • Recover for 400m ( ~3 min)
  • Repeat for a total of 10 sets
  • I also set the treadmill incline to .5%.

After a one mile warm-up the Yassos began. When I got to the sixth or seventh set things were getting pretty tough. I was also concerned about my form getting a bit sloppy regardless of how hard I concentrated on keeping things smooth. I negotiated with myself to stop after 8 sets. By the eighth set I started feeling a bit out of control and did not want to injure myself or puke on anyone. I was done. I ran another 2.5 miles at an easy pace to finish off the workout for a total of nine miles.

So it appears I am not in 3 hr finish shape yet but I plan to give it one more go in two weeks. Will a set of 10 be in my future? I am not sure but it will be fun trying!

Happy Training!

About the author

David Hanenburg David Hanenburg is the passionate dirt-lovin' creator of Endurance Buzz and has been playing in the endurance sports world since 2000 after knockin' the dust off of his Trek 950 hardtail thanks to a friend asking to go ride some local dirt. In 2007 he ran his first ultra on the trails and fell in love with the sport and its people. For more information on David's endurance sports journey, check out the About page.

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