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What the interval?

The other day we had a workout with 100m sprints and rest built into the workout.  I noticed that attendance was a little low that day, and for the people who did come, we were met with lets say a lackluster response to the workout.

I wanted to take a second and talk about the importance of interval training and why you should do it, and do it more often.

I will spare you a ton of deep exercise physiology discussion but you should know that the body derives energy through three primary systems.   The first system doesn’t produce lactic acid and is called the phosphogenic system.   The second produces lactic acid as a by product and is called the glycolytic system.  In both of these systems  they don’t use oxygen.  The last system is aerobic which means it uses oxygen.

Which system you use depends primarily on two things the intensity of the effort and the sustained duration of the effort.  Using a phoshogenic system is quick burning and high octane.  It’s used for any effort that goes from nothing up to around 10 seconds.  Any effort that passes 10 seconds begins to enlist the glycolytic system, and this system is used up to and around 2 minutes of sustained effort.  After that the aerobic system kicks into gear.  The aerobic system is kind of like using diesel fuel slow to burn but can burn forever.

Are you eyes glazed over yet?  I know what does this have to do with sprints?

When we sprint something like 100m for most people it was an effort that lasts anywhere from 10 seconds (world class sprinter to somewhere less then 2 minutes).  This puts your energy production squarely in the gylcolytic system.  By doing the hard effort and resting the amount of rest we allotted you are training your body to produce a max effort for longer and then recovering to do it again.

Now let’s back it out a little bit.  Producing a hard effort and then recovering does that sound familiar?  Maybe something like Fran which for the elite athletes runs around 2 minutes?  What about a workout like Helen which has a hard effort of KB swings and pull ups and then a recovery run?  Sports anyone?  Basketball, hockey, all the bat sports, tennis…… all these sports require quick bursts and then a recovery.  One can make a strong argument for football as well.

BUT let’s take it one step further….. let’s say you were walking down the street and someone jumps out to grab you…. You better believe you want to be able to provide a sustained burst of speed……. Or maybe he does grab you and you are in a fight for your life, you better be able provide an explosive effort that lasts at least two minutes and hope you can recover from it.

So the next time we have sprints embrace it…. They’re important.

And  oh yeah they’ll also make you a better and faster runner but that’ll be another discussion. 🙂

7-17-14 WOD



1 x 8; 1 x 8+

Met Con:

Thrusters x 20

Burpees x 20

Double Unders x 20 or 100 singles

3 rounds for time


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