Last month’s issue of the British Journal of Sports Medicine contained eight different studies that, in various ways, offered support for Dr. Noakes’s still-controversial views. The most significant was a study led by Mr. Beltrami, with collaborators in Norway, Britain and Australia, that turned the standard incremental VO2max test on its head and used a “decremental” test instead.
Mr. Beltrami’s 26 volunteers started by performing a conventional incremental VO2max test. Then, on a separate day, half of them repeated the incremental test while the other half performed a decremental test. After a brief warm-up, the decremental test ramped immediately to a speed higher than the maximum speed reached in the previous incremental test. After about a minute – just before the subjects were about to fall off the back of the treadmill – the speed was decreased by one kilometre an hour. This process was repeated over and over, with the speed being lowered just before the subjects reached failure.
In the group that did two incremental tests, VO2max scores remained the same; but in the decremental group, VO2max scores increased by an average of 4.4 per cent. In other words, the subjects were suddenly able to transport more oxygen to their muscles, simply because the test structure was altered – a clear indication that it wasn’t a fundamental property of the heart, lungs or muscles that created the initial plateau.
The researchers reasoned that, since the subjects knew that the decremental test would become progressively easier, their brains would be less likely to pre-emptively apply the brakes in self-defence. Since emotional stress can affect blood flow and metabolism, that knowledge alone could alter their physiological response to exercise.
There was one further surprise: When the subjects did a final incremental VO2max test at the end of the experiment, the group that had previously performed the decremental test maintained their new higher max – a result that left even Mr. Beltrami puzzled. Whatever additional exercise capacity was unlocked by the novel decremental protocol somehow persisted.
For now, the study raises more questions than it answers. But it suggests that some of the limitations we encounter during hard exercise may actually be self-fulfilling prophecies – and that knowing your VO2max is less important than believing that you can go a little faster or a little farther.
Ote Alex Hutchinsonin
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