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Time to Test?

Physiologic testing is one of the most valuable and undervalued tools available to athletes. Objectively characterizing one’s fitness can provide the data necessary to create a training program which is the most effective and efficient possible. Whether you are a professional or recreational athlete, training efficiency is massively important! If you spend ten hours per week training, you would hope to get the maximum benefit from every one of those ten hours. The same holds true if you spend thirty hours per week riding or running. Everyone’s time is limited, and no one wants to waste that time on ineffective training.

If you have undergone testing in the past, then regular retesting serves to objectively evaluate your training plan, your progress, and whether changes need to be made. If you’ve not tested previously, then setting a baseline is invaluable for moving forward in the most efficient manner.

So, what should you be testing? And is it safe to do this testing during a pandemic?!?

Endurance athletes are often familiar with the concepts of VO2max and lactate threshold. Let’s quickly look at each of these and the manner by which we measure them.

VO2max - This is the maximum volume of oxygen (fuel) that the body can inhale, circulate, and then effectively use at the muscular level. I like to tell my patients that this is how we measure “the size of the motor.”

Lactate threshold - This is a complex topic that we are going to keep simple for these purposes. When muscles work and produce force, lactate is produced. The harder you work, the more lactate is produced. While being produced, the body also consumes lactate as a fuel for further energy production. It’s a pretty elegant system! At a point, you produce more than the body can effectively clear or utilize. That is when lactate begins to accumulate and an athlete’s failure is imminent. The point at which this happens, and the various kinetics around this process, serve to define a person’s fitness. If we continue the “motor” analogy, lactate threshold is kind of like the “red line” on your body’s tachometer.

Body composition - This one is simple! Body composition is a measurement of how much lean mass you have, as compared to fat. No one wants their fat mass to be high, but we also have to worry about it being too low. This is an important balance to achieve, for both health and performance.

VO2max is traditionally measured by wearing a mask which captures and measures the gasses you breath in (oxygen) and out (carbon dioxide), as well as the rate at which this happens. Quite candidly, in this time of respiratory viral pandemic, I would not be too keen on doing such a test. While the testing apparatus can be cleaned, it’s just not something that appeals to me when evaluating whether to undergo an elective test such as this.

Lactate is measured with a simple finger-stick blood sample. Sometimes the earlobe is used as well. Either way, this is a more controllable process which requires no reusable masks or filters. I also consider lactate metabolism to be more useful and actionable than VO2max when evaluating a person’s fitness. Some lactate measurement actually allows for estimation of VO2max though, so it’s possible to look at both metrics through one test.

Body composition is measured in numerous ways. DEXA is the gold-standard for this measurement, and it only requires a patient to lay on a table and be scanned. This process allows for easy cleaning of equipment and very low risk of viral transmission.

With all of that in mind, my preference for athletes at the moment is to undergo lactate testing and DEXA scanning to evaluate their current fitness. If testing protocols are carried out in a reasonable manner and equipment cleaned (which should not be novel to this pandemic!), it is a low risk way to gather this data.

Throughout my years of doing this, many athletes have preferred to wait and test when they are at their fittest. While I understand this mentality (which I call the “video game effect”…trying to see what their best score would be), that’s not very helpful when trying to prescribe the most efficient and effective training program. In fact, I much prefer to obtain a baseline to see where we are starting. We can still measure later to get that “high score”, but obtaining numbers early is crucial.

During the pandemic, some athletes have doubled-down on training and fitness. Some have let things slide as races and events are canceled left and right. Regardless of how you may have spent the past few months, there’s no time like the present for gathering the data which will help you move forward most efficiently. Whether your goal is race performance or simply improving your overall health, having a road map is crucial as you move forward. A map without a starting location is pretty useless though. Baseline testing provides you with that information so that you and your coach can plot your path to success.


Dr. Kevin Sprouse is trained and certified in both Sports Medicine and Emergency Medicine. He serves as the Head of Medicine for EF Education First Pro Cycling and works with elite and professional athletes across numerous sports and disciplines at Podium Sports Medicine. Dr. Sprouse’s unique experience and expertise are sought by high-performing athletes, executives, and health-conscious individuals across the country and around the world.