endurance lab
The elab is where your training starts.
Most athletes train on guesswork — zones estimated from a formula, fueling figured out mid-race. EPTC's eLab changes that. Before you train, you test. And what we find shapes everything: your zones, your pacing, your nutrition, your coaching plan.
WHY TESTING MATTERS
Knowing your VO2 max is useful. Knowing your lactate threshold is useful. But knowing how both interact with your race goal, your training history, and your fueling habits — that's what actually moves the needle. That's what EPTC's exercise physiologists do with your data.
WHAT WE TEST
What the lab measures — and what it means for your training.
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A foundational metabolic test for athletes who want to stop training on estimates. We measure your VO₂ max, anaerobic threshold, FATmax, and training zones using a graded exercise test on a bike, treadmill, or rower. You'll leave with a complete picture of your aerobic fitness, how your body uses fat versus carbohydrate at different intensities, and training zones that are actually calibrated to your physiology — not a formula. If you're just getting started with data-driven training, this is where to begin.
Fitness Assessment (GX test) $299
Follow Up* Fitness Assessment (GX test) $279
Sweat Test & Fitness Assessment $449
*within 6 months of initial test
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Our most complete metabolic test option. In this protocol, we measure body composition, VO₂ max, FATmax, and anaerobic threshold. What makes this different from the Fitness Assessment is that we also measure VLamax (your lactate production rate) and apply INSCYD analytics to the results. From this, you get a better understanding of how your body functions during exercise, training zones calibrated to your physiology — not based on a formula, and how best to use those zones for optimal return on your training time. In most cases, no headgear or face masks are required. This appointment type is for competitive and data-driven athletes who seek more in-depth results. Testing can be done using a bike, treadmill, or rowing erg.
Performance Assessment (INSCYD test) $389
Follow Up* Performance Assessment (INSCYD test) $359
Multisport: Performance Assessment (INSCYD test) 10% discount
*within 6 months of initial test
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A quick, non-invasive test using InBody bioelectrical impedance analysis. What you get is more useful than a weight reading: body fat percentage, lean muscle mass, and segmental muscle and fat mass, visceral fat score, tracked over time so you can see what's actually changing with training or overall nutrition and lifestyle changes. Useful for any individual monitoring body composition through a season, or anyone who wants a more honest metric than weight alone.
InBody Test $59
InBody Test Follow Up* $39
*within 6 months of initial test
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Measures how many calories your body burns at rest and — more usefully — what fuel mix it's drawing from. By analyzing your respiratory gas exchange while at rest, we can tell you your baseline caloric needs and how much of that energy comes from fat versus carbohydrate. Includes an InBody body composition scan. Valuable for dialing in nutrition, understanding how your body responds to training load changes, or building a fueling and nutrition strategy that's specific to your metabolism rather than a generic formula.
RMR test $199
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Lab-quality metabolic data, without the lab visit. Using INSCYD's Power-Performance Decoder, we can run a full performance assessment remotely using data from your existing power meter, GPS watch, or heart rate monitor. We also offer field testing on course and group sweat sodium testing for teams and clubs. A practical option for athletes who can't make it in regularly, coaches working with a squad, or anyone who wants to test in their actual training environment.
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Finds the exact exercise intensity at which your body burns the most fat — your personal FATmax. During the test, we track how your fuel usage shifts between fat and carbohydrate as intensity increases, identifying the precise zone where fat oxidation peaks. The result is a personalized fat-burn zone you can train in, along with nutritional guidance on how to support it. Particularly useful for anyone whose body composition goals are tied to how they train.
Maximal Fat Burning Assessment $299
Follow Up* Maximal Fat Burning Assessment $279
*within 6 months of initial test
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This measurement can be added to a Performance Assessment visit to see how much oxygen your body requires to run at a given speed — and by extension, how efficiently you're turning energy into forward motion. Small improvements in running economy have an outsized effect on performance, especially over longer distances. We assess both aerobic and anaerobic contributions at submaximal speeds, and factor in biomechanics, body composition, and neuromuscular strength. Results include a personalized plan to improve your efficiency, and a baseline for retesting as your form and fitness evolve.
Running Economy Test (Initial Test & Consultation) $249
Follow Up* Running Economy Test $199
*within 6 months of initial test
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The test measures the concentration of sodium in your sweat — a number that varies enormously between athletes. Knowing your requirement can have a direct impact on performance, cramping, and recovery. If you've ever wondered why generic hydration advice doesn't seem to work for you, this is usually why. You'll receive a personalized hydration strategy with specific guidance on fluid and electrolyte intake before, during, and after exercise.
Sweat Test $199
Sweat Testing Buddy Rate (2 people) $369
When combined with either a Fitness or Performance Assessment appointment, $150
Group Sweat Testing (3+ people) is available onsite or remotely at a location of your choice.
TWO WAYS TO USE THE eLAB
Whether you train with us or on your own, the lab is where clarity starts.
Standalone testing
Come in for one assessment or a panel of tests. You'll leave with your data and a one-on-one consultation to understand what it means. Some athletes use this to calibrate their self-directed training. Others return seasonally to track progress.
Testing as the start of coaching
Every EPTC coaching program begins with lab testing — it's not optional, and that's intentional. Coaching without testing is guesswork. If you're considering working with a coach, a lab assessment is how that relationship starts.
Not sure which is right for you?
Located at 8 Madrona St., Mill Valley — right at the base of Mt. Tamalpais.
Open Monday–Saturday, 8:30am–6pm.