
A bold claim you might say more likely to appear in an advert for a dodgy fitness supplement than a serious training blog but a recent observation noted in work from the group of Tim Noakes (http://bjsm.bmj.com/content/46/1/23.abstract) suggests that you may be able trick your brain in to releasing the brakes on your VO2max.
The group set out to test the theory that the bodys maximal oxygen consumption (VO2 Max), a key determinant of athletic ability, is limited by the cardiovascular system. Noakes however has long believed that it is the brain not the cardiovascular system that limits VO2 consumption during exercise, a theory know as the central governor theory.
By cleverly redesigning the traditional incremental VO2max test, where maximum O2 consumption is reached by gradually raising the intensity in set stages, they hoped they could trick the brain in to permiting higher than normal O2 consumption. They created a decremental test where exercise begins at a very high intensity and is reduced consecutively at defined points.
“We reasoned that if subjects knew beforehand that the test would become progressively easier the longer it continued, the possibility was that any biological controls directing the termination of exercise might be relaxed, thus allowing the achievement of a VO2max higher than that achieved with conventional [incremental test]“

Indeed when they subjected runners to a series of VO2 max tests including initial incremental then either incremental or decremental tests they found the decremental test gave significantly higher scores. This result supports the theory that it is not the cardiovascular system but possibly the brain that limits VO2max.
A report published at the same time using a closed loop test with self selected pacing confirms that traditional tests do not elicit true Vo2max(http://bjsm.bmj.com/content/46/1/59.abstract).
The remarkable thing with first study however was when they retested the subjects at the end with a final traditional incremental test they still maintained a higher VO2 max following a decremental test.

There was no increased performance associated with the increased VO2max presumably because it was elicited by biological trickery rather than hard training but that does not mean to say that having “unlocked” this extra VO2max it would not facilitate training to a higher level.
Should we all go a perform a decremental VO2max test now to unlock our unused aerobic potential? It is imposible to say but it would be interesting to follow these athletes to see if they can turn this increased VO2max in to increased performance.
Certainly the use of decremental high intensity intervals in training can be very effective but perhaps we just did not realise that there was a component of “brain training” involved. If you want to try this sort of training yourself a good place to start is with 4x3min where the first minute is extremely hard close to max, the second minute in at VO2 max and the 3rd minute is at threshold. These hard intervals require large amount of recovery ~4-5minutes but I promise threshold has never felt so easy.
If you want to try the decremental they used in the study I recommend you find a good sports scientist to supervise you as it is a highly demanding and complicated protocol that shouldn’t be attempted without support. It is also likely the stress of operating a treadmill yourself would negate the effect.