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Juerg Feldmann

Fortiori Design LLC
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 #1 
Here a very nice article, who  explains extremely well the struggle we  all have in understanding the complexity of physiological testing. But as well it outlines  nicely the reluctance of established  centers and groups to let go the traditional idea of testing everybody and any sport  in their lab with a VO2 max test.
  A great idea to collect  data's for any  publication but  pretty worthless to help out in setting training intensities and  prediction in performance.
 Why would VO2 predict a performance.
 How the opposite a performance may predict the VO2 ??? Most likley hard to do.
 MOXY resp the   dynamic of  O2 in the working muscles can help us in the future to understand performance.
  Ideas like  an increase in SmO2 may create an increase in lactate or  a decrease in SmO2 may predict an increase in lactate has to be looked upon in a much more practical way.
  Isa it a contradiction or a physiological reality .?
 Is it the unseen real versus the unreal seen.
 Here some thoughts before we enjoy the article on VO2 max.

And keep in mind Dal monte's great work many years back, which simply got pushed under the table, as it  did not fit the reality of the time   .
 Example:
 You  create a hyperventilation ( for example moving  into altitude .) a untrained respiratory system will  create the hyperventilation by reducing TV and increasing RF. This  drop's the EtCO2 down easy under 30 in some cases.
 This shifts the O2 Dias curve to the left meaning great SpO2 values but  bad release of  O2 from Hb. Meaning with MOXY great SmO2 values.
. Due to this shift of the O2 Diss curve we have problem to release  O2  and will have by the same wattage a higher  need to  produce  or use ATP o2 independent   creating a H + production above and beyond we would have on sea level and  therefor triggering a higher CO2 production which than  triggers and even  bigger shift to the left and a lactate production  will show up with a lag  with values  not seen  at seam level.
 Result SmO2 high lactate high

 Now  in sea level no respiratory limitation so  O2 diss curve not influenced  so we use O2  in a  work and we will see a drop as  expected of SmO2  and a increase in lactate due to limitation of mussel activity rather  respiratory  system.
 This explains the results we see in the BPR team  when we  looked at LBP lactate reaction  and compared the different reactions with the SmO2.  See  the 2 exampels from the  Vernon Balance point team SmO2 reaction and lactate trends as one exampels of the  situations SmO2 and Lactate dynamic.
 
 Now here enjoy VO2 readings 

 

VO2 max: Not the gold standard?

Tony Leyland

In my article on exercise science in last month’s CFJ, I highlighted the difficulty of scientifically determining optimal training methods. Most often, it is coaches working hands-on using a trial-and-error methodology that actually push the science ahead. Eventually, scientists notice that most coaches are doing a particular thing with success and then design a study to determine why it is effective.

However, coaches’ practical, field-tested insights and clinical experience don’t necessarily translate into the realm of scientific testing and study design. I was recently contacted by a coach working with the Canadian National wrestling team. One of the wrestlers was competing in the 62 kg class, but the coaches thought that if he could drop down a weight class he would be able to medal at the Olympics. They wanted him to drop from 62 to 55 kg, but realized that he was, understandably, concerned about how he would perform after dropping over 11 percent of his body weight. So they wanted him to get a few weight-cutting practice trials in before he actually had to do it in competition. He was to act like it was a wrestling meet and cut down for weigh-in at 6 p.m., rehydrate overnight, and then go through some physiological fitness tests in the morning. They wanted to see how his body handled the cut-down and hopefully give him confidence that he could maintain fitness and perform normally while dropping that much weight. That is where I come in: they wanted me to conduct the morning fitness tests at my university.

The tests they wanted to use were a VO2 max test (aerobic capacity measured while working to exhaustion on a treadmill or stationary bike) and a Wingate test (a bike test designed to assess both anaerobic pathways). Not a good idea in my book, as those tests do not mirror the performance required by the wrester in his sport. They would not very effectively test the wrestler’s ability to perform at the tasks required for his event—which was the whole point of the experiment.

So why did they suggest tests that are clearly not the best to assess the athlete’s performance? I think it is because we all have a tendency to work with standards that are universally accepted. (Maybe this is why CrossFit is viewed with suspicion by some: it doesn’t put much stock in the standard tests for evaluating fitness. How can people compare CrossFit’s methods and results with others? How can they evaluate and quantify the fitness it produces? Nobody else uses tests called “Fran,” “Linda,” etc., to measure progress. The unfamiliar is always suspect.)

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VO2 max: Not the gold standard? (continued...)

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The VO2 max test on a treadmill or stationary bike measuring gas exchange is considered the “gold standard” of laboratory tests to assess VO2 max (the conventional measure of aerobic fitness), which is why the wrestling coaches wanted to use it for their athlete. But does it transfer to a wrestling match? Olympic freestyle wrestling bouts consist of three rounds of two minutes each. Wrestling is an exceptionally demanding sport using multiple lines of action (pushes, pulls, and static grips with both the arms and legs) and demanding both cardiovascular endurance and muscular stamina, so why not asses all these abilities in one test? You could do three two-minute rounds of one minute of thrusters and then one minute of pull-ups (like a Fran), or maybe three sets of two minutes of clean and jerks (like a Grace). This would tax the cardiovascular system as well as muscular strength, power, and endurance, and the athlete’s scores for each would measure changes in his fitness. You could also develop a continuous six-minute test similar to Fight Gone Bad that would cover many of these aspects and be indicative of the wrestler’s VO2 max. To break the testing into a VO2 max test (which would quantify how well he pumps blood to his leg muscles and the stamina of those muscles) and a Wingate test (which is a 30-second maximal-output bike test to assess phosphagen and glycolytic energy pathways) doesn’t adequately test the demands of the sport.

If you wanted to assess other energy systems separately, you could test the phosphagen system with a maximal sprint (say, 60 meters) or, if you wanted a very short-duration power test, you could use a vertical jump or clean and jerk. As for the glycolytic system…well, I think any self-respecting CrossFitter could think of something extremely intense using multiple muscle groups that you could sustain for only 90 seconds before collapsing in a heap on the floor.

When I discussed these issues with the wrestling coach, I got a very positive response. It made a lot of sense to him (as did the thought that he wouldn’t have to pay for expensive tests). Also he now has complete control on the timing of the test and he can repeat it more frequently than relying on my university to conduct the test.

Athletes are competitive by nature and love to challenge themselves, so I frequently get calls asking me to measure VO2 max and body fat percentages. As with the wrestling coach, I usually tell people to save their money. There is no need for expensive tests to measure these variables and there is good science to prove you shouldn’t. I’ll talk about percent body fat at another time but this month I want to focus on VO2 max.

VO2 max is a measure of your body’s ability to take up and utilize oxygen. VO2 max is measured by determining the amount of oxygen in the inspired air and the expired air. The difference is the amount of oxygen used by the body. This is usually done by analyzing inspired and expired gases while having the subject run on a treadmill with ever-increasing speed and/or incline until exhaustion.

At sea level, the most important physiological factors that determine VO2 max in a given person are:

the ability of the heart to pump blood

the oxygen-carrying capacity of the blood (hemoglobin content)

the ability of the working muscles to accept a large blood supply (amount of capillarization within a muscle)

the ability of the muscle cells to extract oxygen from the capillary blood and use it to produce energy (number of mitochondria and aerobic enzymes)

Delivery of oxygen to the blood via the lungs is important, but at sea level it is not a limiting factor. Most people can get adequate amounts of air into the lungs. The last two points in the list above are really why I thought that a running or biking VO2 max test for the wrestler wasn’t a good idea. A runner may have a large stroke volume (amount of blood pumped by the heart per beat, #1 above) but if you put him on a bike, his VO2 max measurement will come out lower than when he is tested on a treadmill. Similarly, a cyclist will not do as well on a treadmill. This is because of the difference between systemic adaptations to the training impulse and peripheral adaptations. Both runner and cyclist have large stroke volumes but the runner’s quads cannot accept as large a volume of blood and extract oxygen as efficiently as the cyclist’s quads. Likewise, the hamstrings and especially the ankle extensors (gastrocnemius and soleus) of the runner are able to receive larger amounts of blood and extract oxygen more effectively than those of the cyclist. So VO2 max is specific to what you are doing. In truth, there is no single, movement-agnostic

VO2 max. There is a “running VO2 max,” a “cycling VO2 max,” a “thruster VO2 max,” etc.

The highest VO2 maximums recorded are for cross-country skiers, as they utilize the most muscle tissue in their event. I wonder what the VO2 max of an elite CrossFit athlete would be while doing thrusters. You could have a series of barbells set up with different weights and increase the weight being thrusted every three minutes until the athlete couldn’t sustain that power output (similar to increasing the speed and/or inclination of the treadmill). Not an easy test to administer, but it is interesting to consider. The VO2 max recorded would undoubtedly be a very high value.

Another important point to keep in mind about measuring athletic performance is that there is daily variation in our physiological parameters. If you measure your heart rate upon waking each morning, it will vary from day to day. So will the maximum heart rate you can achieve on any given day. It has been reported that there can be up to an 8% variation in the VO2 max due to this natural daily variation (we are not robots responding to stimuli exactly the same way every time). So why pay for one VO2 max test when you are trying to determine change? You need at least two measures. But even two tests aren’t ideal, as the difference is likely to be affected by daily variation and other factors such as hydration, nutrition, and environmental temperature, rather than changed VO2 max per se.

So the best thing is to have simple tests such as a 5k run that you can easily repeat six or seven or more times a year. If your time improves consistently, you know your running VO2 max has improved. Over the year and multiple tests, variation due to factors other than improved running VO2 will cancel out. This is why it is so easy to test yourself while following CrossFit: the benchmark workouts become the standardized tests. You might not hit a PR every time, but you will see which direction you are heading in and how steep the trend curve is.

If you actually want a specific numeric measure of your VO2 max (in ml of oxygen utilized per kg of body weight per minute), you can run a 1.5-mile test (6 laps of a standard 400-meter track) or run for as far as you can on the track in 12 minutes. The links below will take you to calculators that will estimate your VO2 max based on your results:

Sure, there are errors in these predictions compared to a test that actually measures the O2 content in your inspired and expired breath (the gold standard of testing, remember), but they are free and repeatable whenever you can find a 400-meter track and a stopwatch.

Not a runner? Test yourself at 150 wall-ball shots for time. If over the year your time decreases, your VO2 max for wall ball has improved. And that is good to know. However, you must be able to sustain any movement you want to use to test VO2 max continuously for about 6 minutes or more. If wall ball with a 20-pound ball overloads your arms so that you have to break sets and rest, it wouldn’t be the best choice for evaluating VO2 max. Using a lighter ball (and maybe even adding to the number of shots) so that you can work continuously for 6 minutes or more would make it work as a test of your wall-ball VO2 max. So for anyone thinking of getting an expensive fitness test done, don’t bother. Spend your money on useful things, like the CrossFit Journal or another medicine ball or another set of rings so your friends can join you in actually improving your fitness rather than worrying about how to quantify it.

 

Tony Leyland is Senior Lecturer at the School of Kinesiology at Simon Fraser University in Vancouver, Canada. He has taught at the university level for 24 years and has been heavily involved in competitive sports such as soccer, tennis, squash, and rugby as both an athlete and a coach for over 40 years. He is a professional member of the National Strength and Conditioning Association, a Canadian National B-licensed soccer

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