Cardio Fitness
Most people have never had their cardiorespiratory fitness measured. We test it and build a program around it.
VO2 max is one of the strongest predictors of all-cause mortality. We measure it with a metabolic cart, set evidence-based targets by age and sex, and coach a Zone 2 training program designed to move the number. Then we retest to confirm it worked.
How this protocol works
This isn't just testing. It's a coached cycle designed to get you where you want to be.
What we measure
VO2 max
How long you'll live, in one number
Maximum oxygen uptake, measured with a metabolic cart and a submaximal ramp protocol. Not estimated from a watch. This is one of the strongest predictors of all-cause mortality, and most people have never had it tested.
Zone 2 benchmark
Monthly progress tracking
Same workload, same modality, every month. This tracks your aerobic improvement over time without requiring another VO2 max test. Your team reviews trends and adjusts your program.
Resting HR & HRV trends
Recovery and training readiness
Wearable-derived resting heart rate and heart rate variability, tracked over weeks. Declining resting HR and rising HRV indicate cardiovascular adaptation. Sustained drops in HRV flag overtraining or external stressors.
What’s different after this protocol
You know your VO2 max — not an estimate from a watch, but a lab-measured number that places you against population norms for your age and sex. You know whether your aerobic fitness is protecting you or putting you at risk.
You’ve spent a full training cycle on a Zone 2 program built around your thresholds, with monthly benchmark sessions tracking whether your aerobic capacity is actually improving. Your team monitors resting heart rate and HRV trends to confirm your body is adapting.
At the end of the cycle, we retest VO2 max with the same metabolic cart protocol. The number either went up or it didn’t. If it moved, you know the program is working. If it didn’t, we figure out why and rebuild for the next cycle.
What this protocol delivers
- Your VO2 max measured by metabolic cart, with your percentile ranking for age and sex
- A Zone 2 training program built for your tier, equipment access, and schedule
- Monthly Zone 2 benchmark sessions tracking aerobic improvement over time
- Resting HR and HRV trend monitoring via wearable data
- Coached training with regular check-ins
- A full VO2 max retest showing what changed
- Integration with Strength & Power and Stability & Mobility when running in parallel
”Do you exercise?” is not a fitness assessment
At your annual physical, your doctor asks if you exercise. You say yes. They check a box. That’s it.
But “I exercise” says nothing about your cardiorespiratory fitness. Low VO2 max carries a mortality risk comparable to smoking. A person in the bottom 25th percentile for their age has roughly 4x the all-cause mortality risk of someone in the top quartile.
The problem: nobody measures VO2 max outside of a research lab. Your Apple Watch estimates it (and gets it wrong more often than not). Your gym tracks your pace. But nobody has put you on a metabolic cart, measured your actual oxygen uptake, and built a training program around the result.
You wouldn’t manage your cholesterol without a blood test. Why would you manage your cardio fitness without measuring it?
The plan: Zone 2 training cycles
Assessment, program, coached training, retest. Your team runs the same VO2 max protocol at the start and end of each cycle, so the number either moves or it doesn’t.
See how a cycle runs
VO2 max assessment. Your team measures VO2 max with a metabolic cart and submaximal ramp protocol. Based on your percentile ranking, you’re assigned a cardio tier. Your Zone 2 heart rate range and training targets are set from the test data — not from an age formula.
Program delivered. Your team delivers a Zone 2 training program matched to your tier and equipment access. The program specifies modality (bike, row, run, swim), session duration, weekly frequency, and heart rate targets. Zone 2 is the foundation. Higher-intensity intervals are added for Development and Performance tiers.
Coached training. Monthly Zone 2 benchmark sessions track aerobic improvement without requiring another VO2 max test. Your team monitors resting HR and HRV trends from your wearable. When trends stall or drop, your program is adjusted.
Full retest. Same metabolic cart protocol. VO2 max is compared to your baseline. The next cycle is planned based on where you landed.
We match the program to where you are
Three tiers. Foundation (Tier 1) builds a base — consistent Zone 2 sessions at the right intensity. Development (Tier 2) adds structure and volume for members who train but without measurement. Performance (Tier 3) pushes VO2 max higher with interval work and periodization.
[CLINICAL INPUT NEEDED: Specific VO2 max percentile thresholds for tier assignment by age group. Graduation criteria for tier progression. Session cadence and volume prescriptions per tier.]
Common questions
Is this protocol right for me?
A few patterns fit. You exercise regularly but have no idea whether what you're doing is improving your cardiorespiratory fitness. You've never had your VO2 max tested and want to know where you stand relative to your age group — not an estimate from a wearable. You're over 40 and want to protect the aerobic capacity that declines roughly 10% per decade without intervention.
How does this work?
We test your VO2 max with a metabolic cart, assign your cardio tier, deliver a Zone 2 training program, coach you through it with regular check-ins and wearable data review, and retest to confirm your numbers moved.
Do I need to complete other protocols first?
No. Cardio Fitness can be your first protocol after The Foundation. Your cardiovascular data also informs exercise prescriptions in other protocols.
I already do cardio. Is this different?
Probably. Most people train at intensities that feel productive but don't build Zone 2 base. We measure your actual thresholds, build a program around them, and track whether your aerobic capacity is actually improving over time.
How does this relate to Strength & Power and Stability & Mobility?
Cardio Fitness targets cardiovascular endurance — VO2 max, Zone 2 output, aerobic efficiency. Strength & Power targets force production and muscular capacity. Stability & Mobility addresses movement restrictions. Many members do all three, sequenced by their clinical team based on assessment results.
What does this cost?
Included in Protocol membership: $695/mo, or $7,500/yr prepaid (save $840). The Foundation Assessment is the on-ramp: $1,500 standalone, included with annual membership.
From the Protocol blog
VO2 max is the number that predicts how long you'll live. Have you ever had it measured?
Not estimated by a watch. Measured by a metabolic cart, interpreted by an exercise physiologist, and used to build a training program that moves the number.
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