QT2.0 VO2 Max Block Comments

QT2.0 VO2 Max Block Comments

What This Phase Is Actually About

The VO2 Max training block exists for one specific reason:
your top-end capacity has become the limiter.

By the time we enter this phase, you are typically in a very Aerobic physiological state. Your Critical Power or Critical Speed is occurring at a very high percentage of your power or speed at VO₂ Max. In other words, your ceiling is too close to your roof.

That sounds good - but it creates a problem.

If the roof can’t move, the ceiling can’t rise.

This block is about creating room again.

1. Muscle Fiber Utilization

Polarized work: roof and foundation

VO₂ Max blocks are intentionally polarized.

Near the Roof

We do focused work:

  • Above threshold

  • Near VO₂ Max

  • At intensities that demand full aerobic utilization and recruit higher-force fibers

This work:

  • Trains the body to use Type IIX fibers aerobically

  • Improves oxygen delivery and uptake at very high outputs

  • Pushes directly on the roof of the house

The goal is not anaerobic power for its own sake. It’s expanding the aerobic contribution of fibers that normally fatigue quickly.

At the Foundation

At the same time, we continue to:

  • Reinforce Type I (slow-twitch) fibers

  • Maintain and slightly expand the foundation of the house

This matters because:

  • A higher roof still needs a foundation that can support it

  • Polarization prevents erosion of durability while intensity rises

This is not random intensity - it is deliberately balanced stress.

2. The Athletic Architecture Model

Lifting the roof so the ceiling can grow

Using the house model:

  • Ceiling = Critical Power / Critical Speed

  • Roof = Power or Speed at VO₂ Max

When we enter a VO₂ Max block:

  • The “physiological attic” is no longer an attic

  • It is closer to a crawlspace

  • And that crawlspace is limiting future gains

At this point, continuing to push threshold work won’t meaningfully raise Critical Power or Speed. The system has become too efficient relative to its top-end capacity.

So the goal shifts:

  • Apply pressure directly to the roof

  • Lift it upward

  • Restore vertical space so the ceiling has room to move later

This is not about refining efficiency. It’s about expanding capacity at the top.

3. Quality, Duration, and Fatigue Accumulation

Quality above all else

Because intensity is high:

  • A large portion of training stress comes directly from intensity, not duration

  • Fatigue dulls the very adaptations we are trying to create

So during a VO₂ Max block:

  • Workout quality is aggressively protected

  • Fatigue accumulation is strictly limited

  • Sessions must be entered fresh enough to push physiological limits

This means:

  • Shorter sessions overall

  • More recovery relative to stress

  • Little tolerance for “junk fatigue”

As a result:

  • CTL growth is modest or flat by design

  • This is not a volume-building phase

  • Progress is measured by capacity, not load

If CTL isn’t rising much here, that’s not a failure - it is part of the plan.

The Big Picture

The VO₂ Max block is about reclaiming headroom.

We lift the roof so that:

  • Future threshold work can be effective again

  • Sustainable performance has space to rise

  • The system doesn’t stall at a false ceiling

If Base/Durability builds the foundation, and Build/TH tightens the structure,
VO₂ Max restores vertical space.

That’s its job in QT2.0.