Identify weakness and train to cope

Trying to train to make an effective difference to Vo2 Max capability can be a hit or miss affair.
There is no guarantee whatsoever that your training will make a difference to your high end capability at staying the course but hopefully this workout will challenging enough to put you in good order.
Recommended 2 to 3 times per week frequency and not to be attempted if in any way feeling less than 100% as your intervals should be carried out to the letter,
If you train by using power numbers then that form of targeting will be of help to pace yourself than otherwise using the heart figures.


Incremented warm up of 12 minutes than short recovery followed by 2  x 2 minute intervals of 107% and 125% FTP respectively.
Repeated 6 times with periods of recovery in between to drop the heart rate fully.
Work session of 24 minutes with a TSS of 101. This is a high enough number to increase chronic training load on a weekly basis when combined with other work that is logged to make for a productive training block of 3 to 4 weeks.
First part of the interval should be ridden with a cadence 100 -110 if possible then go a bigger gear and drop cadence between 90 and 95.

If you feel you can cope with the demands then you can schedule in a fourth workout
With this workout , I am trying to elicit a training response that should match and hopefully overreach race conditions. 

The workout can be done either on a turbo or on the road with a hill of 2 - 3 % that can take you up to 2 minutes to do then if possible reverse and hit the downhill and flat in a big gear and lower cadence. Really try to spin up the legs during the climb to effect heart rate response fully. Continuing with the second 2 minute interval should bring you close to your maximum ability. 

The body fuels systems used in this workout are both the anaerobic and aerobic pathways.
I would emphasize the need to recover as much as possible between workouts.

This diagram


displays how muscle glycogen  is still used as we ramp up the intensity to the extent that glycogen depletion can be an issue after the workout to the extent if not fully recovered you may not complete the intervals correctly.

There is an 'endless' supply of FFAs (free fatty acids ) from adipose tissue and muscle triglycerrides but they will not cope on their own with the energy demand for our high intensity work. However, using up our 'fat' reserves can have the benefit of reducing our body fat to become leaner if that is a desire! 
The by product of our training is that it increases FFA uptake and oxidation and muscle triglyceride utilisation.