[Scott Johnston]

So sorry to have missed this question.  By now you are already closing in on your race.  But hopefully this will help you next time.   Subbing 30-30s for the uphill Z3 work makes sense because this event is shorter and flatter.  The benefit of the 30-30s is that they allow you to recruit higher force fibers and give them an aerobic stimulus.  This will lead to an increase in running economy.

 

Sorry again and good luck in your race,

Scott