Do Increases in VO2max Cause Improved Performance?
If you are an experienced runner then you have likely heard it many times – VO2max limits performance and increasing VO2max causes improvements in performance.
This belief is both widely held and commonly promoted within the running community and has led to runners and coaches devising workouts specifically designed to increase VO2max. For example, Pfitzinger & Douglas, in their book Road Racing for Serious Runners, devote an entire chapter to training methods for improving VO2max and speed.(1) In the introduction to the chapter titled Training to Improve VO2max and Speed they write “Many serious runners know that improving VO2max, or aerobic capacity, is key to racing better.” and “In this chapter, we’ll show you why and how to improve the two main components of racing fitness that runners try to develop with hard workouts – VO2max and basic speed.” In their view VO2max isn’t just important, it is key to racing well. They spend much of the chapter explaining what VO2max is and prescribing workouts specifically designed to increase it.
Another example comes from Dr Jack Daniels in his book, Daniels Running Formula. He writes “To optimize VO2max, the runner must stress the oxygen delivery and processing system to its limit while performing the act of running. I assign a phase of interval training…to accomplish this goal.”(2) Dr. Daniels thinks VO2max is important enough that he assigns an entire phase of training to optimizing VO2max.
Runners and coaches aren’t alone in this belief; exercise scientists believe it too. The link between VO2max and performance is strong enough that physiologists have conducted research studies designed to identify training techniques that will maximize VO2max.(3)
Which, of course, brings us to an obvious question; what does the research have to say on the subject? After all, any physiological belief this strongly-held and generally taught must be supported by the research, right?
Actually, no, it isn’t supported by the research.
A review of the research (4) on this topic actually reveals that:
· “…in well trained athletes VO2max remains stable even when performance is shown to increase.”
· “…in these athletes the correlation between VO2max and aerobic performance can be poor.”
· “…although rarely acknowledged, in the small longitudinal studies that have linked changes in VO2max with changes in aerobic performance, the data have been unconvincing.”
· “…studies using chronic obstructive pulmonary disease patients, recreationally active subjects, and endurance-trained athletes did not observe a correlation between the magnitude of training-induced improvements in VO2max and aerobic performance.”
All of these quotes indicate that the link between VO2max and performance is not what many have long believed and promoted. The fact is that changes in VO2max and performance are not cause/effect as runners have been taught for so many years. The data does not prove that improving VO2max is what causes improvement in performance; in actuality, the data in support of that belief is slim at best.
In 2009 a group of scientists who knew and acknowledged that the data was equivocal decided to revisit this topic. They designed a study to settle the issue by having a relatively large cohort of previously untrained subjects undergo a supervised six week cycling program. By monitoring changes in performance and various physiological parameters, such as VO2max, they were able to provide definitive insights about the link between changes in performance and aerobic capacity.
The basic finding was this – “This study demonstrates that improvements in high-intensity aerobic performance in humans are not related to altered maximal oxygen transport capacity.”
In other words, changes in VO2max did not cause improvements in performance.
Yes, VO2max improved in the subjects. And, yes, performance improved too. But the changes are not related to each other. “The change in VO2max was not related to the change in time trial performance.”
Training does improve both VO2max and performance but these researchers “…demonstrated that these adaptations do not occur in proportion to each other and do not appear to be determined by the same physiological or biochemical parameters.” In others words, the physiological factors within the body that cause performance to improve are not the same factors that cause VO2max to improve. The things within the body responsible for VO2max improvements are not the same things within the body that cause performance to improve.
The practical implication of this research is this – training specifically designed to optimize VO2max may or may not be the best training to maximize performance. Since different factors are responsible for changes in VO2max and performance, then training to optimize VO2max may not fully train those factors responsible for maximizing performance.
Does this mean you should abandon training designed to maximize VO2max? No, it doesn’t. It means that coaches and runners should not have a goal to maximize VO2max. Instead the goal should be to maximize performance. They should ignore VO2max and focus on performance. There is no need to ever measure VO2max in an effort to evaluate the effectiveness of a workout or a program. The only standard by which to judge training effectiveness is performance.
1. Pfitzinger P, Douglass S, Road Racing for Serious Runners, 1999, Chapter 2
2. Daniels, Jack, Daniels Running Formula, 1st edition, 1998, page 39
3. Midgley A, McNaughton L, Wilkinson M., Is there an optimal training intensity for enhancing the maximum oxygen uptake of distance runners? Empirical research findings, current opinions, physiological rationale and practical recommendations. Sports Med, 35: 117-132, 2006
4. Vollard N, Constantin-Teodosiu D, Fredriksson K, Rooyackers O, Jansson E, greenhaff P, Timmons J, Sundberg C., Systematic analysis of adaptations in aerobic capacity and submaximal energy metabolism provides a unique insight into determinants of human aerobic performance, J. Appl. Physiol., 106: 1279-1286, 2009