Vo2Max Intervals

First week on the Base to Race XC MTB Intervals (low volume). I’m curious about the rationale of the Zone 5/VO2 Max: 3 minuters workout. It’s an hour and half long workout, and after a 5 minute warm-up, it called for a 37-minute high Zone 2 ride before going straight into the first of two sets of 2x3s Vo2Max intervals.

I completed the workout on the turbo and had to really empy the tank on the fourth interval. I don’t understand why there was a really long Zone 2 ride before the intervals, and I wondered if I couldv’e performed them even better with about half the Zone 2 duration.

Is this simply to challenge you more? Does this make up for not having many Zone 2 only rides in the XC-MTB plan?

When I was about half way through the Zone 2 effort, I kept thinking I’d really like to start the intervals and it seemed a little like I was wasting time. Anyway, I’d love to hear what the idea is behind this. Thanks in advance.

You may be missing the forest for the trees:


-37 minutes of Zone 2 fatigued you enough to have an impact on your ability to complete the workout

-You struggled to complete 4x3 minutes in Zone 5 (I didn’t check the workout, but I’m assuming the efforts were in Zone 5).

Your FTP is set too high, at least for the day/circumstances.

That may mean your FTP is set unrealistically high, or that your FTP was set outdoors and you struggle with the same power indoors.

30 minutes is the traditional amount of time to warm up before intervals. The extra 7 minutes was to make a nice round number for a 1.5 hour ride.