Metabolic Testing

Big Tree Laboratory is Endurance Company’s performance headquarters. We perform metabolic and performance testing. 

Metabolic testing allows us to find your optimal training zones and monitor training adaptations as you progress through a training program. Eco currently offers a comprehensive metabolic assessment consisting of: Resting Metabolic Rate, Body Composition Analysis, VO2max Testing, Lactate Testing, and Performance Economy Testing.

Metabolic testing gives a very accurate snapshot of your current fitness. Results from a metabolic test can help determine you resting metabolic rate, fuel usage at varying intensities, and training zones.

There are four types of metabolic tests we administer

  1. Resting metabolic rate (how much energy you expend at rest, which is useful for weight management)
  2. Sub-max test (measure of your economy, or how much oxygen you burn at varying sub-maximal intensities)
  3. VO2 max test (amount of oxygen consumed when you are working at maximal effort)
  4. Lactate test (amount of lactate you produce at varying intensities)

Both the VO2 max test and lactate test are available for running (you are tested while you run on a treadmill) or biking (you are tested while you ride your bike on calibrated ergometer with power meter). Both methods allow the test administrator to adjust the intensity as the test progresses. The beauty of these tests is that you receive not only fully personalized training zones, but also pace, heart rate, and power at each training zone.

Finding your proper training zones is critical to maximize training and performance. Training in the proper zones:

Read THIS ARTICLE for more insight in to the importance of knowing your training zones.


The Metabolic tests consist of one or more of the following evaluations:

  1. Resting Metabolic Rate Test
  2. Sub-max Test
  3. VO2 max Test
  4. Lactate Threshold Test

We like to add body composition analysis to the testing to get a more complete picture of your physiology.

Resting Metabolic Rate Test
This test measures the amount of calories you burn at rest and what percent of these calories come from fat and carbohydrate. This is a useful test in determining daily energy needs and helping with weight management. You will sit quietly for 10-15 minutes while breathing through a mask which is attached to the metabolic analyzer.

Sub-Max Test 
The Sub-Max Test is a measure of your economy, or the amount of O2 you consume for a given workload. This is especially helpful for endurance athletes who wish to know their economy at race pace (i.e. marathon pace or ironman bike pace). This test provides a snapshot of your current economy (amount of O2 at a given speed or O2 needed to reach a given speed) and allows follow-up testing to measure economy improvements. For example, during your initial test, you may require 1800 ml of O2 to run at a 9:00 mile. After a couple of months of training, you may only require 1700 ml of O2 to run a 9:00 mile. This shows improved economy: you are running the same speed at less O2 requirement. The Economy Test is performed at the same time as the Lactate Test. Data we gather from during the Lactate Test is used to determine your economy.

VO2max Test
VO2max, or VO2peak is considered one of the most important measurements in fitness and performance. The VO2max tests measures the amount of oxygen you consume at your maximum workload. This test is performed either on a treadmill (for running VO2max) or on a rear wheel bicycle ergometer (for biking VO2max). Note that your running VO2max and biking VO2max will likely be different (running VO2max is higher). Often these variables are called the VO2peak when we talk about different modalities (bike versus run). Throughout the test, you will breathe through a mask that is connected to the metabolic analyzer. The test begins at a relatively low intensity. The intensity is incrementally increased so that you reach your maximum workload in about 6-9 minutes. The test is stopped when I determine you have reached your VO2max, but often the athlete likes to continue running/biking until they are unable to continue. The results of this test provide you with your current VO2max in absolute terms (liters ofO2 per minute [L/min]) and in relative terms (milliliters of O2 per kilogram per minute [ml/kg/min]) as well as velocity at vO2max (vVO2max).

Lactate Step Test
Lactate is a byproduct of glucose metabolism. We constantly produce lactate, even at rest. At sub-threshold levels, we are able to metabolize or ‘clear’ lactate as it is produced, thus keeping the blood lactate levels at a steady sub-threshold level. Once we begin to produce lactate at a rate faster than we can clear it, lactate levels begin to rise. A common misconception is that lactate causes the burn we experience as we surpass our threshold, but lactate itself is not harmful and is actually a good energy source for the heart and muscle! Blood lactate is a measure of our ability to metabolize glucose and provides a good way of determining when we rely on predominately anaerobic metabolism. Lactate threshold occurs anywhere between 70% – 88% of your VO2max. Typically, the more trained the athlete, the lactate threshold will occur at a higher percentage of the VO2max.This test is performed on either the treadmill (for running) or on a rear-wheel bicycle ergometer (for biking). You will breathe through the mask connected to the metabolic analyzer. The test begins at a relatively low intensity. The intensity is increased in 4-minute stages. Near the end of each 4-minute stage, data is collected: pace/speed, power (if on the bike), heart rate, perceived exertion, O2 and CO2 levels in expired air, and blood lactate. Blood lactate is collected via needle prick on the tip of your finger. A drop of blood is placed on the lactate analyzer to provide a measure of blood lactate. You continue through 4-minute stages until appropriate blood lactate numbers are reached. You will not go to maximum effort during this test.

Body Composition Test 
Body composition will be measured by two methods: 1) skin folds – various sites on your body will be lightly pinched and measured. The results are plugged into an equation to provide an estimation of your body fat. 2) Bioelectric Impedance Analysis (BIA) – four electrodes are placed on the hands and feet. The device sends a electrical current throughout the body (you cannot feel this electric current!). Data from this test will be plugged into an equation which provides an accurate estimation of body composition. In addition to these two methods, height, weight, waist circumference, and hip circumference will be measured. You will receive your current body fat percentage as well as your height, weight, and Body Mass Index (BMI), and waist and hip circumference. All of these measurements are useful in overall health and for tracking body composition and training changes.

What do you get?
After completing all five evaluations, you will know your Resting Metabolic Rate, Body Composition (body fat percentage, BMI, height, weight, waist and hip circumference), VO2max, velocity at VO2max (vO2max), Lactate Threshold, and Economy at varying intensities. Along with these data, you will receive a detailed breakdown of your training zones as well as detailed explanation on using these zones in your training. A sample of a run training zone chart is below:

Check out THIS ARTICLE to learn about ECo terms for the zones.

Note: other paces like ½ marathon and marathon pace will be provided, but, as will be discussed during the test results explanation, may not be optimal zones to consistently train at.

How can YOU get tested?

ECo’s Metabolic testing involves anywhere from one to five evaluations during one or two lab visits. You can pick one test or choose a combination of tests.

If you pick the complete testing package, the visits would be on back-to-back days, or within the same week. Your resting metabolic rate, VO2max, and body composition will be evaluated on the first visit, while your lactate threshold and economy will be evaluated on the second visit. Each visit will take approximately one hour.

What does it cost?

If you don’t want all of the tests, you can pick some of the tests. The disadvantage of only doing the VO2max or Lactate Test is that the training zones are not as optimized as if both tests are performed.

Contact us to set up an appointment.