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 to help you.
"The testing process was straightforward, easy to execute and easy to understand. I left with relevant numbers, and specific, actionable training recommendations based on my test results. leaving with specific training recommendations was a huge plus, many testing protocols simply spit out physiologic data."
Sam Bassetti
Professional Road Cyclist - Voler Apparel Factory Racing
WHAT WE TEST
What the lab measures — and what it means for your training.
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A foundational metabolic test for anyone who wants to start an exercise regimen, benchmark their progress, or refine an existing one. Using a unique exercise-testing protocol and clinical-grade instruments, we measure body composition, VO₂ max, anaerobic threshold, and FATmax. We then use these results to present you with insight into 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. If you're just getting started with data-driven training, this is where to begin. We test for cycling, running, or rowing. This appointment includes a 1-hour consultation for results interpretation and recommendations.
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 testing option. We measure body composition, VO₂ max, anaerobic threshold, and FATmax. Additionally, and what makes this different from the Fitness Assessment, we measure VLamax (your lactate production rate) and apply INSCYD analytics to the results. This gives you a more granular analysis 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, making it a better option than the Fitness Assessment for runners. This appointment type is for competitive and data-driven athletes who seek more in-depth results. We test for cycling, running, swimming (off-site), and rowing. This appointment includes a 1-hour consultation for results interpretation and recommendations.
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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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 economically you run. Small improvements in running economy have an outsized effect on performance, especially over longer distances. Results include a consultation on how to interpret, track, and improve your running performance.
Running Economy Metric (Performance Assessment add-on) $99
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Measures how many calories your body burns at rest and — more usefully — what fuel mix it's drawing from. Analyzing your respiratory gas exchange while at rest shows baseline caloric needs and how much of that energy comes from fat and carbohydrate. An InBody body composition scan is included. 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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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, segmental muscle and fat mass, and 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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Finds the exact exercise intensity at which your body burns the most fat — your measured 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-burning exercise zone, along with nutritional guidance to support it. Particularly useful for anyone whose body composition goals are tied to how they train. We test for cycling, running, or rowing. This appointment includes a 1-hour consultation for results interpretation and recommendations.
Maximal Fat Burning Assessment $299
Follow Up* Maximal Fat Burning Assessment $279
*within 6 months of initial test
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This test measures the concentration of sodium in your sweat — a number that varies enormously between athletes. Understanding your requirements and how they change with exercise intensity, duration, and environment can have a positive impact on performance 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.
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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 on-course field testing 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. Please contact us for more information and pricing.
TWO WAYS TO USE THE eLAB
Whether you train with us or on your own, the lab is where clarity starts.
Standalone Visits
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.
coaching Programs
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.
Stop guessing. start testing.
Located at 8 Madrona St., Mill Valley — right at the base of Mt. Tamalpais.
Open Monday–Saturday, 8:30am–6pm.
Interested in Field, remote or group testing?
"When I joined Endurance three years ago, I was an aging ‘weekend warrior’ simply looking for variety in my workout regimen. Tim then introduced me to the benefits of incorporating their lab science into my training, which took my fitness to a new level. Last summer, he used my testing data to design a training program that enabled me to enjoy the Death Ride… seriously. This weekend I rode in the Levi Gran Fondo. To say that l am a big fan of Endurance would be an understatement."
PT