VO2 What?

In the world of endurance, it seems that you cannot discuss fitness without discussing VO2 max. Ask any endurance athlete about it, and you will hear epic stories with names like Indurain, and LeMond. Many of you, however, may find yourselves wondering what exactly VO2 max is and why is it so important. To better understand this concept; let’s take a little trip back to school, specifically back to physiology class. According to the Essentials of Strength Training and Conditioning textbook, VO2 max is the maximum amount of oxygen in millilitres one can use in one minute per kilogram of body weight (ml/kg/min). In other words, maximal oxygen uptake (VO2 max) is the greatest amount of oxygen that can be used at the cellular level for the entire body. VO2 max has been found to correlate well with an individual’s degree of physical conditioning and has been accepted as an index of total body fitness. Numerous studies show that one can increase his/her VO2 max by working out at an intensity that raises the heart rate to between 65 and 85 percent of its maximum, for at least 20 minutes, three to five times per week. The estimated mean value of VO2 max for male athletes is about 3.5 liters/minute and for female athletes is about 2.7 liters/minute.

Now that we know what VO2 is, we can now answer the question, “Why is it so important?” For the endurance athlete, VO2 has long been considered the Holy Grail of fitness. The common rationale is the better one can utilize oxygen, the higher the level one can perform in endurance events. Is this, however, really the case?

Although VO2 max is an important component of any endurance program, I have both good and bad news for those of us who have may not have chosen the right parents! The bad news is that according to Exercise Physiologist Neal Henderson, Coordinator of Sport Science at the Boulder Center for Sports Medicine in Colorado, VO2 is approximately 80 percent genetic. Other estimates put this number anywhere between 30 to 60 percent. Whatever the number is, one thing is certain; there is a genetic ceiling for VO2. The good news is that VO2 is trainable. Unfortunately, if Neal Henderson’s 80 percent estimate is correct, and your VO2 is, for example, at 45ml/kg-/min (average), your best may only be 52 ml/kg-/min after a 20 percent gain (52 ml/kg-/min is considered to be good or just above average).

To put this into perspective, cross country skier Bjorn Daehlie measured at an astounding 96 ml/kg/min. The highest VO2 max ever recorded in a lab was 300 ml/kg/min! This, of course, did not belong to a human but rather a pronghorn antelope. How they got the antelope to run on the treadmill I’ll never know, but I promise I’m not making this up. Thoroughbred horses have a VO2 max of around 180 ml/kg/min, and Siberian dogs running in the Iditarod Trail Sled Dog Race sled race have VO2 values as high as 240 ml/kg/min. To add even more perspective, Olympic marathon winners and elite runners like Jeff Galloway, Alberto Salazar and Frank Shorter check in among the low to mid 70s.

The good news is, like the previously mentioned runners, although you may be at your genetic potential, there are many factors besides VO2 max that can also influence your success in endurance performance. Improving efficiency and economy of movement as well as raising your anaerobic threshold (AT) can lead to performance enhancements in the absence of increases in VO2. These three components can all be addressed through a functional strength training program. Now let’s take a closer look at each of these components.

Continuing on in our physiology lesson, now would be a good time to talk about lactate threshold (LT) and its relationship to VO2. Dr. Stephen Seiler of Masters Athlete Physiology and Performance says, “For the endurance athlete, a high VO2 max is like having an invitation to the big dance but having an invitation to the dance does not ensure you will dance with the prettiest girl.” If you want to dance with that girl, you are going to have to work on your LT! (And you thought it was big guns and washboard abs that attracted the girls.) LT, as pointed out in one of my previous articles (see Lactic Acid; The Good, The Bad, and The Ugly), is the point where the body produces more lactic acid than it can clear. Training LT will result in a decrease in lactate production at any given exercise intensity. Untrained individuals usually reach the LT at about 60 percent of VO2 max. This means that even if my VO2 is 70 ml/kg/min, which is an elite level, I can only use 60 percent of it, or 42 ml/kg/min (average), before my LT shuts me down. With training, however, LT can increase from 60 percent to above 70 percent or even higher. Elite endurance athletes typically have an LT at or above 80 percent of VO2 max. Although most endurance athletes usually train LT in the pool, on the bike or during the run, we have several protocols in the gym designed specifically to improve LT. Furthermore, because specificity of movement is very important when training LT, these protocols address both the lower and upper body (see Table 1 below).

Super Legs

Exercise	Repetitions	Notes
Speed Squats	20	20 reps in less than 20 seconds to parallel
Lunges	20 (10 per side)	Alternate legs, knee just off ground
Box shuffle/split jump	20 (10 per side)	Use 9” box
Squat jumps	10	Squat to parallel and no rest between jumps

Complete entire circuit without resting in less than 1:30

Last but not least, we can now tackle efficiency and economy of movement. The difference between efficiency and economy in an exercise setting is that, for a given energy consumption, economy is measured as movement velocity, while efficiency is measured as mechanical power output. What does all that mean? It means that efficiency and economy can be just as important as VO2 or LT. To better understand this concept, just think of the last time you were out for a group ride. Was it easier to pull at the front or sit in? Sit in, of course! Why is that? Because sitting in allows for more efficient movement and less exertion, which in turn will allow you to be more economical. Think of every joint in a given movement as an opportunity to leak power. The more joints involved in a movement, the more opportunity there is to leak power. The more stable the joint, the less power that leaks. The less power that leaks, the more efficiency in a given activity.

So how do these concepts apply to strength training? Frequently, I am asked to watch someone run on the treadmill and look at his gait. Instead, I ask him to perform 10 anterior reaches on a single leg. If this is difficult, that tells me his hips are not as stable as they could be, and his gait could not possibly be as good as it should be. The same goes for the shoulder joint. If you cannot manage a set of t-stabilization push ups with good form, then your swim stroke is not as efficient and economical as it could be.

Now for all of you skeptics out there, all I ask is for you to just try it out. Perhaps before you go to test your VO2 (no fun, by any means), you might first try taking a look at your anterior reaches or t-stab push ups. These alternatives I have presented are not meant to point out your shortcomings or embarrass you but rather to empower you. Rather than whining about genetics (though I still do), try testing your limits in some of the ways mentioned earlier. I assure you that you will find what my most successful clients have found, that through a comprehensive functional strength training program, economy, efficiency and lactate threshold can be improved, making maximal VO2 less important.

Some famous and not so famous athletes and their corresponding VO2 numbers:

References:

1. Baechle, Thomas and Earle, Roger. "Essentials of Strength Training and Conditioning." Human Kinetics Publishers; 2 edition (August 2000)