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New research shows that believing you’re getting enough exercise can lead to lower weight and better health. This placebo effect also works when objectively you’re not getting enough exercise.
Placebo effect of training
In 2007, researcher Alia Crum of Stanford University, along with colleagues, conducted research on a possible placebo effect of exercising [1]. They wondered to what extent the health effects of physical activity are caused by feeling better about your activity.
To investigate this, the team interviewed 84 chambermaids from 7 different hotels. They also conducted measurements such as body weight, body fat percentage, and blood pressure. The women themselves thought at the beginning of the study that they had little or no physical activity. However, they did not take into account that their work was so physically demanding that they already met the recommended guidelines for exercise (half an hour a day).
Subsequently, half of the chambermaids were informed of this fact. A month later, the researchers returned and asked again how the women felt about their own level of activity. Not surprisingly, the women in the informed group now rated this much more positively. Then, when measurements were taken again, their blood pressure, weight, and body fat percentage had decreased.
Placebo effect of training without training
A placebo effect can be demonstrated in various ways. The above study can be compared to a test in which you give two groups the same medicine, but only tell one group that it was a placebo. After all, all chambermaids had sufficient exercise; only half of them didn’t know it.
However, normally you give one group the medicine and another group the placebo. It’s mainly interesting to see what the effect is when you think you’ve received the medicine. Crum therefore conducted a follow-up study last year with a similar setup. People who incorrectly thought they were getting enough exercise. The question was whether a placebo effect would also occur in this way.
For this, she investigated together with colleague Octavia Zart two American databases [2]. This yielded information from 61,141 participants. They had all answered the question whether they thought they were exercising less, the same, or more than peers. Many of them had worn accelerometers which could objectively measure activity. This information was then linked to the national death index. This allowed them to determine if and when a participant had died.
They found a strong association between premature death and underestimating one’s own activity. Even when accelerometers showed that someone was above average active. The risk of death was 71 percent higher than in the group that thought they were exercising more than peers. This association was also present when corrected for factors such as chronic disease, socio-economic status, smoking, and other known risk factors.
Although this cannot prove a causal relationship, the two are clearly related.
Stress effect of not training
What does that mean exactly? Are you mainly training to convince yourself that you’re getting enough exercise? Could you have just fooled yourself? Not really. It’s probably not about the placebo effect of training, but about the placebo effect of
not training. Or better said; the stress effect.
Take the example of the chambermaids. Zart and Crum (sounds like a children’s series) think that it wasn’t so much the science of enough exercise that caused improvement. It was the previous stress that caused deterioration. The thought that they weren’t getting enough exercise could lead to a higher release of stress hormones and associated consequences. Recognizing that the work provided enough exercise removed that stress factor. Suddenly, there was no longer a need to figure out how to find time to work on one’s own health.
Keep it real or keep it positive?
Yesterday I wrote an article called “overweight, the new norm?”. About researchers who are concerned that people with overweight are increasingly considering the extra pounds as normal. Among other things, this would lead to less effort being made to lose weight. Being too positive about weight would therefore be disadvantageous and could lead to an unhealthy form of ‘fat acceptance’. So, you would think that the placebo effect doesn’t apply to positive thinking about weight. Why else the concern?
However, British research from 2015 shows that it might actually be advantageous to positively assess one’s own weight [3]. Or perhaps better said: That it is negative to negatively assess one’s own weight.
Participants who perceived their weight status as being overweight were at an increased risk of subsequent weight gain. This effect was observed irrespective of weight status at baseline and whether weight status perceptions were accurate or inaccurate
E. Robinson, University of Liverpool
The researchers from Liverpool used data from 14,000 adult Britons. They found that if participants considered themselves too heavy, this actually increased the risk of further overweight. This was regardless of the objective assessment of weight. Thinking you’re too heavy would therefore lead to gaining more weight.
Blissful ignorance?
What does all this mean? We can draw multiple conclusions from this. Let’s look at the different possible situations.
The main one is that stress is not productive. Negative thoughts about your level of activity or your weight are therefore inherently negative. If you (rightly) know you’re not exercising enough and weigh too much, it’s pointless to worry about it as long as you do nothing about it. As long as concerns don’t result in actions, they are therefore quite pointless.
On the other hand, what else is your motivation to take action? If you’re fine with everything as it is, why would you change anything?
Last year, for the first time since I seriously trained, I had a long period of very little training. Initially, I could accept it as a temporary sacrifice. At some point, I couldn’t handle it anymore. Eventually, I even became jealous of the seniors on Good Morning Netherlands who were still getting moving. That stress probably didn’t do me any good during that time. This wasn’t how it was supposed to be, so I got back to work. Now I feel completely like my old self, so I needed that push.
Conversely, I’ve also experienced periods where I was never satisfied with the progress. I say ‘of course’ because many strength athletes and bodybuilders will recognize that. The feeling that you don’t train often or hard enough, that your nutrition isn’t optimal, that you’re not making enough progress. However, I knew these feelings were unfounded. Examples of typical muscle dysmorphia or bigorexia where you don’t see your own gains anymore. As long as I didn’t let myself get carried away by it, I was fine with that. I’ve always been natural, have a normal social life. So I didn’t mind that little voice that kept saying, “harder, more, faster!” Looking at the above study with the chambermaids, I realize that the little voice can not only have mental consequences but also physical ones. That messed with my gains, even more stress! Don’t listen to it.
Conclusion
So don’t worry about your weight or physical activity until you actually do something about it. You may wonder how far you can let it go with your weight and lack of exercise. At some point, the lack of stress will outweigh the lack of exercise and overweight.
Be aware of the activity you do have. Learn to count the walks to the store or the stairs at the office. It’s clear that it’s pointless to wrongly consider yourself as not active enough.
References
- Crum AJ, Langer EJ. Mind-set matters: exercise and the placebo effect. Psychol Sci. 2007 Feb;18(2):165-71. PubMed PMID: 17425538.
- Zahrt OH, Crum AJ. Perceived physical activity and mortality: Evidence from three nationally representative U.S. samples. Health Psychol. 2017
Nov;36(11):1017-1025. doi: 10.1037/hea0000531. Epub 2017 Jul 20. PubMed PMID: 28726475.
- Robinson E, Hunger JM, Daly M. Perceived weight status and risk of weight gain across life in US and UK adults. Int J Obes (Lond). 2015 Dec;39(12):1721-6. doi: 10.1038/ijo.2015.143. Epub 2015 Aug 7. PubMed PMID: 26248659.
