By Rachel Garrod
Is there such a thing as a placebo effect where exercise is concerned? We are probably all familiar with the concept of a placebo effect when related to medicines; it is the reason medical trials have to be so stringent and why people are often randomly assigned to a “treatment” group or “sham” group. Medicines have to be shown to be more effective than placebos before we can recommend them in health care.
Even in physiotherapy trials we often have a “placebo” arm, where the participant in the trial will meet with a physio for the same amount of time as participants in the active arm, but only those in the treatment group will be offered the physiotherapy session that we hope makes the difference. However, we are just now beginning to understand how our mind-set, or our beliefs about the exercise we undertake, seem to have an important role in the effectiveness of that exercise. Sort of like a “placebo effect” for exercise. Allia Crum and Ellen Langer, from Harvard University, investigated whether a person´s perception of the activity they undertake impacts on the health outcomes achieved.
Eighty-four female room cleaners were assigned two different research options. Staff in four of the hotels were offered education regarding the benefit of the physical activity they undertook as part of their job. They were provided with written information specific to their daily work: for instance, vacuuming for 15 minutes burns 50 calories and cleaning bathrooms for 15 minutes burns 60 calories. Those in the intervention group were informed that their work was clearly helping them to achieve and even exceed recommended weekly exercise guidelines and would expend on average 200 extra calories a day. In another three hotels staff were given general information about exercise but not related specifically to their own work.
Before and four weeks after the intervention measures such as waist-hip ratio, blood pressure, weight and body fat were recorded. After four weeks neither group reported any change in their actual weekly physical activities and hotel managers said there was no increase in the daily work performed. However, those in the informed group considered themselves up to 60 per cent more active than previously whereas those in the control group perceived no change. After only four weeks of knowing that their work was good exercise, the subjects in the informed group lost an average of two pounds (0.9 kilograms), lowered their systolic BP by 10 points, and showed significantly lower body-fat percentage and BMI. There was no change in the control group.
Mind-set is important to all aspects of life and, while we still don´t fully understand the placebo effect, we know it’s real. So next time you take your dog for his daily 30-minute walk remind yourself that this will have real cardiovascular and physiological benefits, and help your brain maximise these physical effects by harnessing that exercise placebo effect.
Physiotherapy lecturer and counsellor Rachel Garrod can be contacted at: Tel. (+34) 652 281 122; firstname.lastname@example.org