VO2 Max: Falling Short of The Hype-rventilation (full version)

The VO2 max test is considered by many (myself excluded) to be the gold standard human performance test. It has been largely popularized by a Gatorade add campaign that ran in the early 2000’s featuring beautiful female athletes and well branded male athletes performing maximal treadmill tests. Additionally, during Lance Armstrong’s long reign over the peloton it was well documented that Lance had performed a VO2 max test with a score of 86 ml/kg/min. Naturally an extremely high VO2 max became directly associated with elite aerobic performance. This week I will be posting the 4 reasons the VO2 Max Test isn’t all its hyped up to be. Topics I will address include:

1.       It’s difficult to know if you are actually measuring a subjects maximal oxygen consumption

2.       The VO2 max test downplays the importance of biomechanical efficiency

3.       The VO2 max test downplays the importance of having a high lactate threshold

4.       The formulas used to determine caloric expenditure are poorly validated

Max or Submax- That is the question

                When performing a VO2 max test it can be difficult to determine whether or not true, maximal oxygen consumption was attained. Historically VO2 max tests require the subject to run on a treadmill as long as they can and the amount of oxygen consumed in the last minute of the test is considered the VO2 max. This method often yields sub maximal scores. Physiologically there are four ways to determine whether maximal oxygen consumption has been reached.

1.       No increase in oxygen consumption with an increase in workload (plateau)

2.       Obtaining max HR

3.       RER > 1.1

4.       Blood lactate concentration above 8 mM

At least one of these must occur for a VO2 max test to be considered valid. One must be careful in measuring these criteria, particularly maximal heart rate. Simple formulas like (220-age yrs) are inaccurate and should be taken with a grain of salt.

Downplay of Biomechanics

All other things being equal VO2 max may be the greatest indicator of aerobic performance but all things are NEVER equal. Mechanical efficiency is a metric that attempts to quantify the amount of energy that is being used for mechanical work (running on a treadmill) verses energy given off as heat. With the rise in popularity of clinical testing, biomechanical analysis has fallen by the wayside. Athletes who are biomechanically efficient can “make up” for some of their physiological downfalls. Conversely athletes with elite physiological profiles can shoot themselves in the foot with poor biomechanics.

Downplay of Lactate Threshold

Lance Armstrong’s VO2 max data was incredible but that isn’t what set him apart as an elite cyclist. Lance Armstrong’s super power was his unparalleled ability to utilize fat to produce ATP. Lance Armstrong’s lactate transition occurred at 82 ml/kg/min or at 95% of his VO2 max. This allowed Lance to work at 95 percent of maximal output without fatigue or excess lactate accumulation. Lance relied on the human bodies nearly limitless fat stores to produce ATP rather than the extremely taxing glycoltic pathways.

These are my thoughts on maximal testing. Please comment or email me personally if you wish to discuss this topic. All thoughts, opinions and criticism are valued.

               

V02 Max: Downplay of Biomechanics

All other things being equal VO2 max may be the greatest indicator of aerobic performance but all things are NEVER equal. Mechanical efficiency is a metric that attempts to quantify the amount of energy that is being used for mechanical work (running on a treadmill) verses energy given off as heat. With the rise in popularity of clinical testing, bio-mechanical analysis has fallen by the wayside. Athletes who are biomechanically efficient can “make up” for some of their physiological downfalls. Conversely athletes with elite physiological profiles can shoot themselves in the foot with poor bio-mechanics.

Max or Submax- That is the Question

When performing a VO2 max test it can be difficult to determine whether or not true, maximal oxygen consumption was attained. Historically VO2 max tests require the subject to run on a treadmill as long as they can and the amount of oxygen consumed in the last minute of the test is considered the VO2 max. This method often yields sub maximal scores. Physiologically there are four ways to determine whether maximal oxygen consumption has been reached.

1.       No increase in oxygen consumption with an increase in workload (plateau)

2.       Obtaining max HR

3.       RER > 1.1

4.       Blood lactate concentration above 8 mM

At least one of these must occur for a VO2 max test to be considered valid. One must be careful in measuring these criteria, particularly maximal heart rate. Simple formulas like (220-age yrs) are inaccurate and should be taken with a grain of salt.

VO2 Max: Falling Short of The Hype-rventilation

The VO2 max test is considered by many (myself excluded) to be the gold standard human performance test. It has been largely popularized by the Gatorade add campaign that ran in the early 2000’s featuring beautiful female athletes and well branded male athletes performing maximal treadmill tests. Additionally, during Lance Armstrong’s long reign over the peloton it was well documented that Lance had performed a VO2 max test with a score of 86 ml/kg/min. Naturally an extremely high VO2 max became directly associated with elite aerobic performance. This week I will be posting the 4 reasons the VO2 Max Test isn’t all its hyped up to be. Topics I will address include:

1.       It’s difficult to know if you are actually measuring a subjects maximal oxygen consumption

2.       The VO2 max test downplays the importance of bio-mechanical efficiency

3.       The VO2 max test downplays the importance of having a high lactate threshold

4.       The formulas used to determine caloric expenditure are poorly validated

Four Tips for Better Academic Research Presentations

          Have you ever wondered how professors and other researchers are so good at making convincing presentations out of relatively insignificant data? Last semester I was in charge of a research study that yielded seemingly insignificant results. With my tail between my legs I presented the results to the professor that I work under. In about twenty minutes he re-ran the SPSS statistical reports and had signed me up to present at the ACSM regional conference.  As it turns out I had been approaching the data from the wrong angle.  I am currently in my final semester of graduate school and am finally beginning to pick up on a few “tricks of the trade”. 

1.      Don’t Be Afraid to Turn a Large Study Into Several Smaller “Cohort Studies”

For example, one could set up a product validation study with 100 random participants. If the results are classified as insignificant you could break up the data into cohorts like: post menopausal women, college aged men, college aged obese females etc. You may find that there is a strong correlation in one of these groups.

2.       Save the Pies for Dessert

Another presentation technique I have learned is the art of using graphs. Great researchers ALWAYS use the proper graph. Just because Microsoft Excel allows you to turn one group of data into any type of graph doesn’t mean proper graph selection is unimportant. Steven Phew is considered by many to be the world’s leading expert on graph selection and he has written numerous publications on graph types and color scheme optimization. In his most famous publication, “Save the Pies for Dessert” Steven cautions readers to not use pie graphs. Additionally, he suggests that 3D bar graphs are confusing and misleading.

3.      Thoughtfully Scale your Graphs

First, you must carefully determine how you will label your axes to convey your point to the audience.  After you have labeled your axes you must determine which units you will use on each axis. Then you must decide how you will scale your axes. The following graphs illustrate the importance of proper scaling.

(Indicates Insignificant Difference)

(Indicates Significant Difference)

4.      No Significance can be Extremely Significant

The purpose of most intervention studies is to “prove” that a given stimuli either positively or negatively effects a person. Generally when data that has no statistical significant is frowned upon. Don’t down play the fact that you have just “proven” that a stimulus has no measurable effect on a person. These results are still valid and could be useful. Great presenters are able to turn nominally important data into home run presentations.

ABOUT THE AUTHOR

            Will Hawkins is the President of Will Hawkins Consulting LLC a company that provides cutting edge research collection and presentation packages for health and wellness companies of any size. Learn more about his company at www.willhawkinsconsulting.com or email him personally at will@willhawkinsconsulting.com.