[Scott Johnston]

Martin, thanks for writing in with your great question.  It’s not a simple one to answer though so much on the individual athlete that the best I can tell you is you’ll need to try it and see if it works for you.  In theory, I don’t see anything wrong with stacking 2 Z3 workouts into a day. The benefit is that you can have slow speed and high speed endurance training because training at 3mMol/L in each of these workouts will result in quite different speeds on these repetitions.  The only recommendation I might make in your example is to put the shorter faster workout in the morning with the longer somewhat slower eight minute repetitions in the afternoon/evening.

I hope this helps,

Scott