October L3/4 Vo2Max Building Intervals

We have discussed in pervious posts that it's not always how hard you can do your intervals that will increase your fitness but how much on-time you log.  This is the principle behind these L3/L4 intervals; Maximize L4 on-time to greater increase Vo2max capacity. 

SESSION: 
6 minute intervals (2 min L3, 4 min L4) w/ 3 minutes recovery 

TERRAIN: All uphill 

MODE: Bounding or rollerskiing 

WARM UP:
15 minutes easy 
5 minutes L2
5 minutes easy with accelerations
5 minutes dynamic stretching 
(can also use morning mechanics skate or classic as part of your warm-up routine) 

INTERVALS:
The first two minutes of the 6 minute interval should be targeted on a controlled L3 pace. After two minutes, up the intensity and do four minutes L4 (race pace). 
All uphill terrain is ideal. Use an all-body mode. 
There should be a distinct change in pace and intensity while switching from L3 to L4. (in other words we want to go harder but ALSO faster) 

GOALS: 
This workout might seem overly complicated but we are essentially just tacking on 2-minutes of L3 before doing a standard 4-minute L4 interval. Why? because we want to maximize our on-time this time of year to build aerobic capacity. By starting a 4-minute L4 interval already at threshold we are maximizing our effort in that zone. 

At this point in the training season we should also have done enough intervals to have a distinct L3 and L4 zone and should be able to distinguish those paces. If after the 2 minutes of L3 you can not up the pace chances are you were not below threshold. We want to practice district pace changes between the 2-minutes L3 and 4-minutes L4.