VO2max isn't a genetic ceiling that you either have or you don't. It's the visible expression of seven underlying systems, and most amateur cyclists with low or stalled VO2max are dealing with one of these seven problems specifically. The good news is each one is fixable. The detail is in the 7 fixable reasons your VO2 max is low episode, and this article walks through each in turn with the specific intervention.
Most cyclists who think they've maxed out their VO2max haven't — they've maxed out the stimulus they're applying. Change the stimulus, fix the underlying limiter, and the number moves.
Reason 1: Insufficient aerobic base
The biggest hidden limiter. Cyclists try to push VO2max higher with hard interval work while the underlying aerobic capacity that supports the intervals is undertrained. The result is that the cyclist can't fully recover between intervals, can't sustain the intensity across multiple reps, and the adaptation stimulus is weaker than it should be.
When Professor Stephen Seiler was on the podcast — the detail is in the cycling fast at a low heart rate guide — his framework on this was direct. The aerobic base determines the capacity of the body's mitochondrial network, capillary density, and fat oxidation enzymes. These systems are the support structures for high-intensity work. Without them, VO2max intervals stress the body without producing the adaptation.
The fix is the same as the polarised training prescription. 80% of training time at properly easy intensity (Zone 1–2). Hold this for 8–12 weeks before expecting VO2max work to deliver. The cyclist who runs VO2max blocks on top of a thin aerobic base sees small short-term gains followed by quick plateaus.
Reason 2: Wrong interval formats
The amateur error of doing the wrong VO2max sessions. Two common variations:
Too short. 60–90 second intervals at high power. These hit anaerobic capacity rather than VO2max. Useful as a separate stimulus but they're not the VO2max work. VO2max intervals need 3+ minutes at intensity to push oxygen consumption to maximum.
Too easy. Intervals at 100–105% of FTP for 4 minutes is threshold work, not VO2max work. VO2max sits at 106–120% of FTP for typical cyclists. The intensity needs to push you toward maximum sustainable effort.
The evidence-supported formats:
4×4 minutes at 110–120% FTP, 4 minutes recovery. The classic format. Long enough to push oxygen consumption to maximum, enough recovery to repeat at quality. Most widely studied and most reliable.
5×3 minutes at 115–125% FTP, 3 minutes recovery. Slightly higher intensity, slightly shorter duration. Good for cyclists who can hold the higher power; produces similar adaptations.
30/30s — 30 seconds hard, 30 seconds easy, 15–20 minutes continuous. Different stimulus profile but well-validated for VO2max development. Often easier to execute mentally than the longer formats. Particularly good indoors.
Pick one format and run it for a 4–6 week block. Don't rotate between formats within a block — that fragments the stimulus.
Reason 3: Inadequate recovery between intervals
The cyclist who shortens recovery to "make it harder." This usually produces less adaptation, not more. The recovery between VO2max intervals needs to be sufficient to allow you to hit the same target power on the next interval. If interval 4 is 5% off interval 1, the recovery was too short or the intensity was too high.
The working principle: the goal is total time at VO2max intensity across the session, not maximum suffering. Four intervals at quality produces more time at VO2max than five intervals at compromised quality.
For 4×4 minute sets. 4 minutes recovery is the standard. Pedal easily, drop power to 50% of FTP or below, breathe deeply. If you can't hit the next interval at target power, extend recovery to 5 minutes.
For 5×3 minute sets. 3 minutes recovery. Same principles.
For 30/30s. The 30 seconds easy is the recovery. This format intentionally uses very short recovery because the intervals themselves are short.
Reason 4: Year-round intensity dilution
The cyclist who does VO2max work every week of the year. The stimulus becomes routine. The body adapts to the specific intensity range and stops driving meaningful improvement. After 8–12 weeks of continuous VO2max work, gains plateau and further work just maintains the stimulus.
The fix is block periodisation. Concentrate VO2max work into 4–6 week blocks separated by 8–12 weeks of other focus. The first block of the year might be in late base / early build, focused on lifting the ceiling. A second block might come mid-build, sharpening before key events. Between blocks, the stimulus is base aerobic work, threshold development, or other targeted limiters.
Dylan Johnson's training plan uses this block approach. His 2025 structure includes specific VO2max blocks separated by lower-intensity blocks. The principle is concentrated stimulus followed by absorption and a new stimulus. Continuous low-grade VO2max work doesn't work as well as periodic high-grade VO2max blocks.
Reason 5: Poor warm-up protocols
VO2max intervals need a fully recruited cardiovascular system at the start of the first interval. Cyclists who go from cold to first interval immediately produce poor first-rep quality, which compromises the whole session.
The working warm-up structure:
Minutes 0–10. Easy Zone 1 spinning, just turning the legs over.
Minutes 10–15. Build to Zone 2 / low Zone 3 progressively. Heart rate rising, sweat appearing.
Minutes 15–20. Two or three short sharp efforts of 30 seconds at VO2max intensity, with 90 seconds easy between. These wake up the cardiovascular system and the neuromuscular pathways.
Minutes 20–22. Easy spinning. Final settling.
Minutes 22+. First VO2max interval.
The 20–22 minute warm-up may feel excessive but it makes the difference between a session that hits the targets and a session where the first interval is 5% off. Indoor VO2max sessions particularly benefit from longer warm-ups; outdoor benefits from being able to roll the warm-up into the ride.
Reason 6: Breathing limitations
The under-recognised limiter for cyclists with strong legs but a "blowing up" feeling on VO2max efforts. The diaphragm and intercostal muscles fatigue before the legs, and the cyclist can't sustain the oxygen demand the legs require.
The detail is in the breathing for cyclists guide and the related respiratory training research from Dr Andrew Sellars. His French study showed 6% FTP gains over 48 weeks of structured respiratory training — and the gains transfer directly to VO2max capacity.
The fix is inspiratory muscle training. A resistive breathing device (POWERbreathe or equivalent) at 60–80% of maximum inspiratory pressure, 30 breaths per session, twice daily. Total time investment about 10 minutes. The adaptation builds slowly across 6–12 weeks.
For cyclists who feel their VO2max is breath-limited rather than leg-limited — common in cyclists who report "I can't get enough air in" during hard efforts — this addresses the actual limiter. The work doesn't replace VO2max intervals but compounds with them.
Reason 7: Stale stimulus
The cyclist who's been doing 4×4 VO2max intervals on the same route at the same pace for three years. The session is functional but stops driving improvement. The body has fully adapted to that specific stimulus.
The fix is varying the stimulus while preserving the principle. Same VO2max target intensity, different formats. Same total time at VO2max, different terrain. Same number of intervals, different durations.
Rotation examples:
- Block 1: 4×4 minute intervals at 110% FTP on a steady climb.
- Block 2 (8 weeks later): 5×3 minute intervals at 115% FTP on rolling terrain.
- Block 3 (8 weeks later): 30/30s on the indoor trainer.
The body experiences each block as a new stimulus because the specifics vary. The total VO2max stimulus is preserved; the adaptation continues.
What "good" looks like
VO2max ranges for amateur cyclists, with the caveat that these vary by age, training history, and individual genetics:
Male amateurs. 45–55 ml/kg/min is typical for recreational cyclists. 55–65 for serious club cyclists. 65–75 for competitive amateur racers. 75+ is exceptional and approaches pro territory.
Female amateurs. 40–50 ml/kg/min is typical for recreational cyclists. 50–60 for serious club cyclists. 60–70 for competitive amateur racers.
Watts at VO2max (often more useful for training):
- For male amateurs at 75kg: 320–400W is typical, 400–480 is good, 480+ is excellent.
- For female amateurs at 60kg: 240–300W typical, 300–360 good, 360+ excellent.
These are general ranges. Lab tests for VO2max are the most accurate measure; field tests using the relationship between FTP and peak 5-minute power are reasonable estimates. The 5-minute peak power is roughly 110–130% of FTP for trained cyclists, and corresponds approximately to VO2max power.
When NOT to chase VO2max
The aerobic base must be in place first. Cyclists with low Zone 2 capacity will see small gains from VO2max work before plateauing quickly. The base work that should precede a VO2max block is typically 8–12 weeks of structured Zone 2 work.
Avoid VO2max blocks during heavy life stress periods. The high cortisol environment of work stress, family stress, or sleep deprivation compromises the adaptation to high-intensity work. The same block in a calmer life period produces substantially better outcomes.
Don't run VO2max blocks back-to-back. The adaptation from one block needs time to consolidate before another block can produce further gains. 8–12 weeks between VO2max blocks is the working interval.
After major events. The recovery cost from race phase typically requires 2–4 weeks of light work before another VO2max block can be productive.
Block placement in the annual structure
Where VO2max blocks fit in a typical periodisation cycle:
Block 1: Late base / early build phase. 4–6 weeks of VO2max work after 8–12 weeks of base. This lifts the ceiling that subsequent threshold and race-pace work operates underneath. Typically February to early April for cyclists targeting summer events.
Block 2: Mid-build phase. Optional second block, depending on the rider and the event schedule. 4–6 weeks of refined VO2max work, often with different formats from Block 1. Typically late April to early June for cyclists targeting summer events.
Block 3: Pre-race sharpening. Very short block (2–3 weeks) immediately before peak phase. Short sharp VO2max efforts with reduced volume around them. This is more about neuromuscular sharpening than peak adaptation.
The 30-day fitness sprint protocol covered in boost your cycling fitness in 30 days is one application of a concentrated VO2max block within a longer training cycle.
What to do next
Start with the Plateau Diagnostic — four minutes, free, returns the one change most likely to move your numbers. For many cyclists who think VO2max is the limiter, the audit reveals the aerobic base under it is the real bottleneck. If VO2max is your specific limiter and you haven't run a focused block in 12+ weeks, slot one into the next 4–6 weeks. Use the 4×4 minute format at 110–120% FTP, one session per week, supported by polarised base work the rest of the week.
Set your zones via the FTP zone calculator so the 110–120% target translates to specific power numbers.
For specific protocol coaching, the Not Done Yet community at $195/month runs weekly sessions where VO2max-specific questions come up regularly — format selection, block placement, and how to combine VO2max work with the rest of the training year. For full one-on-one programming, the Roadman Method at $297-397/month builds VO2max blocks into the structured 12-month periodisation.
VO2max is trainable. The cyclist who's stalled isn't at their ceiling — they've just stopped applying the right stimulus or supporting it with the right base. Fix one of the seven reasons. The number moves.