The placebo effect: Why it’s actually great for athletes

Australian researchers have just published some remarkable findings about a new post-exercise "recovery oil."

In the two days following a hard workout, volunteers felt better and regained their strength more quickly compared to a control group. In fact, the recovery oil performed just as well as ice baths, a popular but highly uncomfortable recovery method among athletes.

The catch? The recovery oil was actually a liquid soap called Cetaphil Gentle Skin Cleanser, added to a lukewarm bath as a placebo.

"We made sure that we put the recovery oil in the water in plain sight of the participants, and we gave them a glossy summary of some made-up research about scientifically proven benefits of 'recovery oils,'" says Dr. David Bishop, a professor at Victoria University in Australia. Bishop's doctoral student James Broatch led the study, which was published in the journal Medicine & Science in Sports & Exercise.

The findings revive a long-standing debate about whether ice baths, along with other popular but controversial recovery aids such as compression garments, can really undo exercise-induced muscle damage after it has already occurred.

They also raise a trickier question for athletes: If a training aid makes you feel better, does it really matter if the effect turns out to be in your head?

In theory, spending 10 to 15 minutes in water kept at 10 to 15 C is supposed to fight inflammation and accelerate recovery from the microscopic damage to muscle fibres incurred during heavy exercise. Dozens of studies have tested this idea, with decidedly mixed results. A 2012 meta-analysis of 14 high-quality, ice-bath studies found a modest benefit, but the biggest effects were found in measures such as subjective soreness and recovery of strength – both liable to placebo influence – rather than more objective measures such as blood tests that indicate muscle damage.

That's what prompted Bishop and his colleagues to look for a way to distinguish between the physiological and psychological effects.

"I don't think that we suspected that 'recovery oils' would be as effective as the cold-water immersion," he admits. "That was surprising."

This isn't the first study to suggest that the brain plays a role in the popularity of ice baths. Research published last year in the British Journal of Sports Medicine found that the benefits of a post-workout ice bath for rugby players were biggest for those who had the most favourable impression of ice baths before the study began.

A similarly mixed pattern shows up in studies of compression garments, which also seek to tamp down inflammation and prevent the accumulation of metabolic waste after exercise. Some studies find benefits, others don't and belief in their effectiveness is a good predictor of whether they'll work for you.

Another study published by French researchers in 2011 compared two high-tech, post-exercise, recovery protocols: cold vapour from liquid nitrogen at -110 C to cool muscles and constrict blood vessels, and far-infrared radiation to heat muscles and dilate blood vessels.

Though the two methods are seemingly opposites, they produced similar effects – an indication, perhaps, that fancy machines with big price tags and lots of knobs make us feel better no matter what's going on inside them.

But that doesn't mean athletes are about to stop using these techniques – nor should they, according to Dr. Shona Halson and Dr. David Martin, physiologists at the Australian Institute of Sport. "In the past, placebo effects were thought of as a 'fake' effect," they wrote last year in the International Journal of Sports Physiology and Performance, "but today, the powerful performance-related outcomes associated with improved belief in a training program or novel intervention are seen as real effects that need to be harnessed."

Bishop agrees: "It is vital that coaches and sports scientists try and harness the belief effect in everything that they do with athletes," he says. Even if further research finds that ice baths do have benefits for the muscles themselves, that effect may be no bigger than what you get from belief – so you might as well take advantage of it.

If that answer isn't satisfying and you're still looking for a real recovery miracle, then it's worth considering a 2012 study by researchers in Norway.

They put a group of volunteers through a series of leg exercises to induce soreness, and compared the effectiveness of a 20-minute warm-up on a stationary bike before exercise versus a 20-minute cool-down after exercise. The warm-up was the clear winner in reducing soreness over the next few days.

The point: Soreness arises from damage to muscles that are pushed past their usual limits. A good warm-up can ward off some of this damage by loosening up your muscles; but once the damage is done, there's no magic – not ice, heat, compression, or anything else – that can undo it.

So planning your workouts to progress slowly and steadily will do more to ward off soreness than even the fanciest recovery gadget. And you can't beat the price.

Alex Hutchinson blogs about exercise research at sweatscience.runnersworld.com.