>> Wednesday, March 21, 2012
Runner's World featured this study on their website 2 days ago. It's a quick read, and the writer makes some interesting points.
How the Nocebo Effect Can Torpedo Your Training
By: Alex Hutchinson
We all know that placebo effects can influence your response to training. Heck, I sometimes think that 50% of successful training is convincing yourself to buy into the right positive beliefs about whatever it is that you're doing. But what about placebo's evil twin, nocebo?The nocebo effect is the negative effect which follows the administration of a nocebo, that is, of an inert pharmacological or procedural treatment, administered with or without deliberate damage intention. It represents the counterpart of the better known placebo effect, whereby a positive effect results from the activation of specific neural pathways by a sham procedure devoid of intrinsic therapeutic properties for the condition being treated.
That's from the intro of a new study in the European Journal of Applied Physiology, from researchers at the University of Turin in Italy. As they explain, the nocebo effect has been particularly well described for pain, as well as for other conditions like asthma and allergies, but it hasn't been explored much in the context of sports and training. So here's what they did.
With 70 volunteers, they conducted a series of experiments involving leg extension tests to exhaustion:Before starting the experiments, the researchers applied an electrode to the quadriceps of each subject and performed a test to determine the threshold at which they started to feel the jolt of electricity. Then the subjects were told that, during the experiment, their quads would receive an electrical jolt just below that threshold of sensitivity -- so they wouldn't feel it, but (they were told) it would "increase their sense of fatigue by adding an external cause of weariness." In reality, no electricity was applied during the experiments.
The first experiment was simple. They started with a baseline test, lifting 50% of their 1-rep max until exhaustion; then, in a separate session, they did it again with the "nocebo" electrode applied to half the subjects. Sure enough, while the control group increased the number of extensions from 31.0 in the first session to 35.4 in the second session, an increase of 14.9% (probably due to familiarity with the procedure rather than training effects), the nocebo group decreased by 4.6%. They expected that it would feel harder, so it did.
The second experiment was quite a bit more complicated. Its goal was to distinguish between the effects of expectation (we're told that a pill or electrode will make us better or worse, so it does) and conditioning (we learn to associate a pill or electrode with better or worse feelings, and respond accordingly, like Pavlov's dogs salivating at the bell). This experiment involved four different sessions, and included secretly increasing the weight that the subjects were lifting during the second and third sessions so it would feel like the nocebo electrode was really making things much harder. In the end (to cut a long story short), this extra conditioning didn't make the nocebo any more powerful than the simple expectation used in the first study.
So what does this tell us? Interestingly, it suggests that nocebo effects are, if anything, more powerful than placebo effects, since you don't need to be "conditioned" to get the full effect:[W]hen negative or potentially dangerous outcomes are involved, it may not be necessary to depend on first-hand experience, as during conditioning. Rather, human beings can rely on the evolutionary advantage provided by language, enabling them to integrate other people's experiences, as with verbal suggestions.
In other words, if someone tells you that something you're doing will make you slower, you'll believe it -- and in doing so, you'll make it true. This, of course, brings to mind all sorts of cliches ("If believe you can do it, you're right; if you believe you can't, you're also right"). But I think it's a message that is sometimes forgotten: when athletes begin to doubt themselves -- or their coaches -- it can spin into a self-fulfilling spiral of failure. I think that's a big part of the reason athletes who leave one coach to train with another often see such a big boost in performance: it's not just the positive beliefs associated with the new coach, it's also getting rid of the negative beliefs associated with the old one.
What do you think? I buy it.
Thoughts? I'll respond back to keep the dialog going.