More on the Placebo Effect
The Washington Post has an article on the results of an interesting…and somewhat odd study presented at the Endocrine Society’s annual meeting. The study focused on the effects of human growth hormone (HGH) injections on athletic performance – but with a twist. The researchers gave either HGH or a placebo to a group of 64 men and women who were recreational athletes between 20 – 40 years of age. At the end of the two month study period, the subjects were asked to rate their performance improvement during the time they were receiving the injections, and to guess which group they were in.
Ho and his team found that about half of the participants who received a placebo incorrectly assumed they had been given HGH. Gender played a significant role in such perceptions: the male placebo athletes were much more likely than the female athletes to have mistakenly thought they were in the HGH group.
However, regardless of gender, athletes on placebos who thought they had taken HGH typically believed their performance had improved during the study.
What’s more, these “incorrect guessers” actually did improve, albeit minimally, in all measures of performance, including endurance, strength, power, and sprint capacity. In one category — high-jumping ability — the improvement was significant.
People in the placebo group who correctly guessed that they had taken a placebo improved their performance by about 1 percent to 2 percent, Ho said. But those who mistakenly thought they had taken HGH showed twice that level of overall improvement — about 2 percent to 4 percent.
Many people mistakenly believe that HGH will boost athletic performance, despite the fact that there’s no real scientific evidence to support this. HGH will increase lean body mass, but researchers are inclined to believe this is the result of fluid retention, not actual muscle hypertrophy.
As noted earlier, the placebo effect is a very real phenomenon – and one that certainly complicates things when trying to evaluate the effectiveness of dietary supplements, especially the ones I typically cover (i.e., for building muscle and strength).
I’ll be curious to see the actual study itself, once it’s published.