Believe it or not: expect to perform well to perform well!

How do you determine whether a sports supplement or any other sports product will significantly enhance your performance? You might think that performing some kind of performance test – for example a time trial – with and without that aid would give you a definitive answer. However, while it sounds logical, there’s more to it than that.

The placebo and nocebo effect

It’s long been known in medicine that the power of positive (and negative) suggestion can provide a real and significant improvement (or worsening) in symptoms. This is the so-called ‘placebo’ or ‘nocebo’ effect. So, when that is the mere belief that a medicine or some other form of treatment will provide benefits, it’s likely it will actually produce some benefits. And these benefits can be had even if that treatment is nothing more than a sham - a completely inert substance that could not possibly benefit the patient in any physiological way. Likewise, the converse is true when a ‘nocebo’ substance or treatment is administered.

The nocebo effect results in a decline in performance due to the mere belief that some kind of intervention or treatment is likely to harm performance, when in fact that intervention is completely inert – having no physiological effect whatsoever. As an example, consider an athlete who experiences a poor performance after having a different and novel kind of cereal for breakfast. Even if that poor performance was down to something else entirely (eg fighting off a low-level virus), he she might conclude and believe that whenever that cereal is eaten in the future, a poor performance is inevitable.

Future performance testing on that athlete would almost certainly find that poorer performances (slower times, higher perceived effort) do indeed occur when that cereal is eaten beforehand, even if that cereal has zero physiological effect on the athlete compared to his/her normal breakfast cereal. That negative effect would almost certainly be as a result of the nocebo effect – ie the belief in a negative effect resulting in a negative effect⁽¹⁾. In short, the placebo effect and its inverse – the nocebo effect – are both very real; when somebody believes that a product will benefit or harm them, their physical performance will reflect this.

Overcoming the placebo and nocebo effect

It’s precisely because of the placebo effect that doctors and scientists need to investigate the potential benefits or side effects of medicines (or other products such as sports supplements) using carefully controlled studies. This means that alongside the medicine, supplement or any other kind of intervention, a control group is used – a group of subjects who go through the same experimental protocol but instead of using the potentially beneficial/harmful medicine/treatment, they are told they’re getting the same treatment but are instead given a completely inert ‘sham’ treatment. Because both groups of subjects experience the same placebo or nocebo effect, you know that any significant difference in outcomes between the ‘real’ group and the control group is not down to the placebo/nocebo effect, but down to the actual treatment.

Placebo vs. no-placebo effects during sports supplementation

In an earlier SPB article, we explored the role of the placebo effect in sports supplementation. What we asked was this: if the placebo effect is real when you give a dummy sports supplement pill or some other kind of treatment, do some of the benefits you receive from a ‘real’ and proven supplement (eg caffeine or creatine) also result from the placebo effect of knowing you are supplementing with a product that has been shown to be effective in previous studies? Put simply, how much of the benefit of creatine, caffeine etc comes from physiological effects and how much comes from the act of ‘taking something’?

It turns out that giving a completely inert pill boosts performance compared to giving no pill or treatment at all, even when athletes understand that the placebo pill could not have exerted any physiological effects whatsoever⁽²⁾! The implication of this finding is that even when a sports supplement possesses a real physiological boost to performance, some of that performance boost comes from the mere act of taking a pill. Indeed, it even turns out that the physical characteristics of a supplement and the amount of choice in the decision to take it (ie whether it’s your choice or on the recommendation of a coach/trainer) can determine the extent of the placebo effect you will receive^(3,4)!