What is a Physiological Assessment? (Part 1)

The human instinct to survive is one our most powerful instincts.  Our early ancestors had to be faster, stronger and smarter in order to ensure their own survival, having to hunt animals and make tools more efficient than other homo genera. Throughout time, this was the greatest measure of health and wellness of a species; the ability to survive.  Today, with significant advancements in technology, we are able to differentiate within our own species the ability to determine who the best at a given task is.  From standardized tests like the IQ or SAT, to entrance exams for school or the military, we are constantly compared to one another and then given a score based on predetermined criteria. In the fitness industry, we measure how “fit” a person is and to do so, there are multiple types of assessments and tests. A popular one being the VO2max test, which determines the maximum amount of oxygen your body can utilize, (and is typically used as an endurance performance indicator).  However, as you will see below, this test looks at the physiological potential of a person, and not what is actually happening within the body.    Many other factors are associated with performance, such as utilization of the oxygen within the muscles, the efficiency of the person’s movement or the amount of physiological and emotional stress they are under.  To get the whole picture, we need to change our focus from VO2max testing to a more comprehensive physiological analysis, so we can not only understand someone’s true potential, but know what is actually limiting us from getting there.

What is a VO2max Assessment?

One of the most specific measurements we have available to look at long distance exercise ability, or aerobic capacity, is the VO2max assessment. This is where you exercise in a laboratory setting, typically on a bike or treadmill, with the intensity of exercise increasing until you cannot continue.  A mask is placed over your mouth to measure the amount of oxygen your breath in and exhale out so that you can determine how much your body is consuming. The VO2max test can provide information regarding ones aerobic capacity, training intensity zones and anaerobic threshold.  The higher your VO2max value is, the greater capacity you have to use oxygen for fuel. However, capacity does not necessarily equate to performance, meaning a more thorough evaluation to determine the weakest physiological link is needed.

What is different about a Physiological Assessment versus a VO2max assessment?

When I started reading more about how the body operates and getting into some of the research, I came to realize that the current VO2max assessment, as I learned in school, only looks at part of the whole picture.  In regards to the human body, which is comprised of many systems, does it make sense to determine your aerobic ability by only viewing one part of your physiology? What about the muscles? How well you move? How does the heart functions? All these questions help to answer the question of : why the person with the highest VO2max doesn’t always win the race? It is these missing assessments that play a huge factor in the physiology makeup in an athlete or individual. 

For example, say you are coaching a 4X100mrunning relay team that isn’t performing well and it’s your job to find out what the problem is. Do you only look at their overall time to see where the problem is? If you do so, you find out that the team is slow, but you don’t know why they are slow? Where is the inefficiency coming from? A better approach would be to look at each individual team member to see if there is a problem? Is it their start? An inefficiency of the baton handoff? Let’s say you time the athletes individually noticed that one runner always has a bad start compared to the others.  Fixing that one issue would help the team (i.e. the whole system) run more efficiently. Which is why we need to address each physiological system individually, from the respiratory, cardiovascular and muscular systems, looking at how we transport, utilize and remove oxygen and other fuel sources. Not just assessing the overall capacity of the system as in a VO2max test.

From this philosophy came the term “Physiological Assessment”, to address the physiological system not only as a whole, but also as separate pieces, to determine how our body reacts to the increased demand of exercise as a whole.  Each system has its own ability to maintain homeostasis, our ability to regulate our internal environment. If we lose the ability to maintain a stable internal environment, it will result in decreased performance, even can lead sickness or injury.  For instance, when we are cold, our blood gets shunted to our vital organs, such as the heart and lungs, as they need to maintain normal function for us to survive. Our body automatically decides that our internal organs are imperative for survival compared to our limbs, which become cold and can possibly be permanently damaged, known as frostbite. We can apply this same principle to our training, by tricking the physiological system to better adapt to the stress we put on it to help maintain in homeostasis with increased demand on the body.

Through this understanding of physiology, we apply a stressor, in our case exercise, to see how each system regulates their environment and at which point they are not able do so.  Getting the whole 4x100 team to train harder will not solve the problem as you need to specifically address the start of the one runner. This is how the Physiological Assessment will help to make your training more efficient and effective.  By determining and fixing the problem, you will make the entire system perform better overall. This is a fundamental shift in our thinking and will provide more useful, detailed information for those who want to get that edge in their sport. Part 2 will go over each aspect of our Physiological Assessment, which is comprised of a movement screen, and a resting and exercise assessment.

Thank you for reading,

Greg Elliott