Session 3: The dreaded Norwegian 4x4s. This is going to work our Vo2 Max…..to the max! We’ll start with an 18 minute warm up to get ourselves ready, and then go straight into the first of the four intervals. 4 minutes at 110% of FTP, 4 minutes easy, repeated 4 times. Don’t forget, if you’re finding it too hard or too easy, you can decrease or increase the intensity using the In-Game Action Bar + and - icons.