Research article - (2007)06, 21 - 28 |
Placebo Effects in Competitive Sport: Qualitative Data |
Christopher J. Beedie |
Key words: Belief, experimental design, performance psychology, research methods |
Key Points |
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Placebo effects in sports research |
Six published empirical studies have addressed the placebo effect in sport. These have demonstrated, for example, that athletes who falsely believed that they had been administered anabolic steroids (Ariel and Saville, It is suggested above that placebo effects are 'masked' in much sports science research, and that this masking presents a false picture of the degree to which placebo effects might impact on real world sports performance. However, it has been suggested that this might not be the case and that placebo effects are more likely to be evidenced in laboratory conditions than in competition (Hopkins, |
Placebo effects in sports competition |
Evidence, albeit anecdotal, suggests that placebo effects do in fact influence performance in competition. A welldocumented example is the account by Vogt, “I was supposed to inject this rubbish into Richard's backside one hour before the start…At the given moment I gave Virenque his injection. That day he rode the time trial of his life, finishing second on the stage to Ullrich. The German started 3 minutes after Richard and caught him, after which the pair had a memorable ding-dong battle all the way to the finish. “God I felt good! That stuff's just amazing ”he bubbled. “We must get hold of it. ”His result did have something to do with the magic capsule - but there is one thing he doesn't know, unless he reads this. I had got rid of the fabulous potion and swapped it for one which contained a small amount of glucose. There is no substitute for self belief… ”(p. 104) Similarly, in discussing West Germany's unprecedented win in the 1954 soccer World Cup final, the then German Football Federation doctor, Professor Franz Loogen stated: “I injected the men with vitamin C because it was supposed to raise their stamina levels…you cannot measure the effect it has, but the players believed in it ”(World champions or soccer cheats? The Daily Telegraph, United Kingdom: 1st April 2004. www.dailytelegraph.com/world champions or soccer cheats.htm) Both these quotes - and it is recognised that being anecdotal, their reliability is open to question from a number of perspectives - hint at the potential for athletes' beliefs to impact on their performance in competitive situations. Similar anecdotes are relatively common; several publications, for example, Murphy and White ( |
Problems in researching the placebo effect |
It is suggested above that anecdotal evidence for the placebo effect in sport is plentiful. However, anecdotal evidence does not constitute scientific data; Vogt's ( The placebo effect per se is however complex to investigate. A major problem is that of classification, that is, what type of effects can be classified as placebo effects? Hopkins, |
Validating placebo effects through experiential data |
Recent research has investigated the placebo effect from an experiential perspective. Beedie et al., It can be seen that by seeking experiential data to support experimental data, Beedie et al., Six studies have addressed the placebo effect in sport. Of these, only one, Beedie et al., |
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Participants |
Participants (N = 30, age M = 31.4 yr., SD = 5.3 yr.) were 17 male and 13 female athletes. They included amateurs and professionals, ex-national champions, national record holders, international representatives, medallists from both World Championships and Commonwealth Games, and one current World Champion. Participants represented the sports of boxing, cycling, decathlon, mountain biking, rowing, rugby, road running, soccer, squash, triathlon, and weightlifting. Participants were from the UK, Ireland, New Zealand, Australia, Denmark, Germany and the USA. |
Procedure |
Institutional ethical approval was granted. Data were collected via an email survey. The benefits and limitations of this method are discussed elsewhere (Upcraft and Wortman, A brief description of the placebo effect was sent to participants: This described the effect as “…a positive outcome resulting purely from a person's belief that they have received some beneficial treatment when in fact they have received a 'sham' or 'fake'. The placebo effect is well documented in medicine, where it is used systematically in researching new drugs and sporadically to treat a range of conditions. Experimental research has also demonstrated that the placebo effect may influence sports and exercise performance. For example, athletes who believed they had been given anabolic steroids over a period of time experienced greater strength gains than athletes who were told they had not received any steroids. This was despite the fact that both groups of athletes received the same inactive substance. Similarly, athletes using a fake respiratory training device experienced similar improvements in performance to those using the real device, and cyclists who believed they had received a performance enhancing substance performed to a higher level in time trials than when they believed they had not”. After reading the above, participants were asked to respond to two questions: 1) 'Do you believe that your performance could be influenced by the placebo effect or by similar false beliefs?' and 2) 'Have you ever experienced a moment in sport in which a false belief affected your performance?' |
Analysis |
Data derived from Question 1 above were classified as 'yes' or 'no'. Data derived from Question 2 were analysed using inductive content analysis (for an overview of this procedure see Jackson, |
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Requests for information were sent via email to 16 potential participants. This number rose to 48 through use of the snowball sampling method described above. 30 replies were received. Participants' responses to any one category are represented in parenthesis as a percentage, firstly as a percentage of total respondents and secondly as a percentage of total recipients. |
The potential for placebo effects to influence performance |
Twenty-nine respondents (97% of respondents, 60% of recipients) indicated that they believed that the placebo effect could influence their performance. Several respondents expanded on this and offered potential mechanisms (below). The single respondent who indicated a negative response did not propose any specific reason for his belief. |
Athlete's experience of placebo effects |
Twenty-two respondents (73%/46%) were able to recall an event in which some form of placebo effect or false belief had positively influenced their performance. Inductive content analysis revealed that these fell into four categories; 1) explicit placebo effects, that is effects resulting from a false belief deliberately propagated by a third party; 2) inadvertent false belief, that is an effect resulting from accidental misinformation either by a third party or by the athlete themselves; 3) ritual, that is, effects related to the customary behaviours of an individual or a sport; and 4) reverse placebo effects, that is the realisation that a substance or technique now discontinued was in fact exerting its influence via a placebo effect. |
Athletes' opinions as to the mechanisms underlying placebo effects |
10 respondents (33%/19%) also speculated as to the mechanisms underlying placebo effects in sport. These fell into five categories which were labelled 1) expectancy; 2) faith in a third party; 3) marketing; 4) change in behaviour and 5) random fluctuation. Several respondents cited more than one mechanism. |
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Data suggest that the majority of respondents believed that the placebo effect could exert an influence on sports performance. Furthermore, 73% of respondents reported experiencing performance effects driven by some form of false belief. Data hint at the often strong relationship between belief and performance, specifically, that an athlete's belief in a substance, a piece of equipment, a technique or even another person, might be a significant factor in their subsequent success. Defining the placebo effect can be problematic. It is clear from the above data that several respondents are aware that a false belief might enhance performance via a conscious decision-making process as opposed to any direct somatic or psychological mechanism. Three respondents made an explicit link between false belief and a subsequent deliberate change in behaviour, for example, a distance runner suggested “I am sure that what would really happen is that I would try harder and achieve a better result believing that this liquid had helped me”. It could be argued that, having been driven by a false belief, such an improvement in performance is legitimately classified as a placebo effect. Conversely however, it could be argued that, having been driven by a conscious decision, such an improvement in performance is simply the result of modified strategy. It is not the intention of this paper to define the placebo effect. It suffices to say however that the problem lends support to the suggestion above that observed experimental effects should be triangulated with testimony from participants. Such an approach would help to ensure that an effect that appears to have been driven directly by an experimental manipulation might not simply be the result of a change in strategy by the participant, or just as importantly, vice-versa. The fact that athletes recognise the potential for false beliefs to impact on performance should be of interest - if not of concern - to all sports scientists. Although not specifically relating to the research questions and thus not included in the analysis above, the testimony of one athlete, a current World Champion, was compelling. He started by speculating that his use of nutritional supplements and his willingness to adopt almost any technical innovation might have amounted to a placebo effect, but concluded: Implicit in the statement is the idea that although the nutritional aids and equipment might have made no difference nutritionally or mechanically, they impacted on his performance positively and significantly, perhaps in a way similar to the energy patches described above. It might be reasonably construed from this athlete's testimony that, had he participated in a hypothetical quasi-experimental study that deprived him of a habitually used nutritional supplement or item of equipment prior to an event, he might have underperformed in that event. Clearly, such beliefs could be described as superstitions, and on that basis, a sport psychologist might encourage the athlete to progressively reduce his faith in them. However, perhaps one of the most intriguing aspects of the placebo effect is the possibility that it interacts with biological/mechanical factors to augment their respective action (or possibly, in the case of the nocebo effect, to limit those actions), as opposed to working in isolation in the absence of any real biological/mechanical effect. In such a case, any attempt to lessen the athlete's faith in a specific biological/mechanical factor might also reduce its eventual contribution to performance. The data reported above do not provide conclusive evidence that the placebo effect influences sports performance. Like Vogt's ( The sampling method employed, snowballing, is designed to allow researchers access to potentially data-rich respondents. However, it also introduces considerable response bias from a number of perspectives, foremost of which is the potential for a self-selected sample. It is possible that recipients who have not experienced the placebo effect or who have either a negative or neutral opinion would not respond (for example, only one of 30 respondents above reported such a negative/neutral attitude, which struck the author as being a suspiciously low figure). However, it was not the aim of the present study to quantify factors such as the frequency with which placebo effects occur in a population, and consequently no attempt is made to generalise the findings or to categorise them either by sport, gender or age (clearly the relatively low number of respondents and wide variety of sports would preclude such a quantitative analysis). Overall, when experiential data above are considered alongside respondents' theories as to the mechanisms underlying placebo effects, and the empirical and anecdotal evidence reported above, there is a case for arguing that the placebo effect might be a significant factor in both sports performance research and competition, and that consequently research into the nature, magnitude and antecedents of this effect is warranted. |
Elucidating the placebo effect in experimental research |
Although perhaps a little unconventional in a discussion, it seems that, having arrived at the conclusion above, some brief mention of how greater insight into the placebo effect might be achieved is warranted. The potential outcomes of an experimental intervention study are presented in Depending on the aims or hypotheses of the study, this might not be significant. However, more seriously, if a 2-condition design is adopted and no significant differences are observed between experimental and placebo conditions (b, d and f), in a well controlled study the only conclusion that can be drawn is that the intervention was unsuccessful. However, given the same outcome, using the 3-condition design it is possible to ascertain whether placebo and experimental conditions did not differ from true baseline (d), in which case the intervention was indeed ineffective, or whether both placebo and experimental conditions resulted in similarly improved performances over baseline (f), suggesting that the intervention was successful, but that it has a significant psychological component. This is a somewhat different conclusion to 'on the basis that the intervention did not perform better than placebo control it was deemed unsuccessful'. In masking any placebo effects, the 2-condition design does not reflect the true mechanisms underlying enhanced performance in the real world, and it is the real world, not the laboratory, that is of ultimate interest to sports science. |
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Data reported above suggests that athletes experience the placebo effect in competitive situations. It is suggested that researchers in sport seek to investigate the impact of the placebo effect on performance via the use of no- placebo control conditions alongside placebo and experimental conditions in experimental research. Such research would perhaps help elucidate the placebo effect, rather than simply controlling for it as has historically been the case. |
Explicit placebo effects |
Two athletes (7%/4%) re-ported placebo effects resulting from a false belief deliberately propagated by a third party. For example, a first year professional cyclist reported: “I was in the bunch and was told to get some food for the team leader with another guy. On our way back to the support car I said 'man my legs are [colloquialism for 'tired'] and there is no way I can get back [to the lead group]. He gave me two white pills and he said after 20 minutes you will feel a million dollars. Sure enough I started to have no pain in my legs and back and this is after a week of already racing. I felt like I was really on form and had loads of power, the rest of that stage was not a problem. The second from last stage was a time trial and again I thought I was in trouble. I went to the guy and asked if I could have a couple more of the magic pills and he gave me two of the same again. I rocked the stage and people were talking about me, after taking second in the stage”. Subsequently the cyclist, having finished second on the penultimate stage, faced a doping control. He went to the team mate and asked what the tablets were. He was told they were sugar pills, and it was evident that this was a 'trick' that had been pulled on new team members a few times in the past. The doping control was negative. The respondent went on to describe his concern that he might have taken an illegal substance and his subsequent realisation, on being informed that he had not (a state of affairs arguably validated by the negative results of his doping control) that he had been able to ride far harder than he believed, possibly purely based on his belief that he had ingested a performance enhancing substance: “I had been tricked and thought I was using a banned substance and the fact was that I was not. I had been given a sugar tablet, but I found that I was able to push myself a lot harder and ride for longer. ” |
Performance effects based on inadvertent false beliefs |
10 respondents (33%/19%) reported that they had performed to a higher than anticipated level as a result of inadvertent false information, either from a third party or from their own mistaken perceptions. A decathlete reported “I lifted a personal best on the bench-press, when I thought I was actually lifting 10kg lighter. Maybe not the placebo effect, but certainly a case where a “limiting belief ”was put aside by accidentally fooling myself!”. |
Ritual |
Placebo effects based on ritual were reported by three respondents (10%/6%). For example, a triathlete recalled: “I guess the most recent and conscious example of the placebo that I have is the rather dubious habit we triathletes have of shaving our legs. To be honest with you I shave my legs for a completely psychological advantage, and I'm happy to admit it. This year I distinctly remember the effect because I had taken some 1500m swim times a few days before and so was very much aware of my swim form at that very point in the season. I jumped in and was immediately struck by my new found streamlined sensation as I was cruising through the water, I vividly remember feeling sleek, efficient, 'clean', and when I finished that day I found that I had taken 38 seconds off my previous time. A few days later when did another 1500m time trial I was only 10 seconds faster than my 'with hairy legs' time. Placebo? I believe so…”. |
Reverse placebo effects |
Reverse placebo effects, that is, an improvement in performance associated with a substance or intervention that was sustained even after discontinuation of that substance, were reported by five respondents (17%/10%). An ex-professional rugby player stated: “I could list all sorts of training methods that I believed improved my performance but in retrospect make me laugh. I believed Deep Heat was essential preparation for the muscles prior to intense exercise. When I found it wasn't and stopped using it, unsurprisingly my performance and flexibility did not diminish (!)”. |
Expectancy |
Seven respondents (23%/14%) proposed that, in their view, belief in the efficacy of a substance or item of equipment is likely to influence its effects on performance; for example “Yes, to a degree I think my performance could be enhanced if I were under the impression I was taking something or receiving treatment to improve performance”; “If someone believes that something will enhance their performance there is a good chance that it will ”and “I strongly think that when we are taking any type of supplement or medication that our mind convinces us that the product will work”. This was expanded upon by a respondent who suggested: “…the issue to me is really whether you believe that what you are taking will be advantageous to performance or not. If you believe it will, regardless of physiological impact - so long as it is not deleterious to physiological ability - performance will improve”. |
Faith in a third party |
Five respondents (16%/10%) speculated that the coach athlete relationship was critical to the placebo effect, for example: “I believe all human endeavors could be manipulated by the placebo effect if the recipient (of the placebo) believed it to be true. Given that most placebo's would be administered by a third party (coach, doctor, physiologist etc.) it might well be the athlete / third party relationship that would determine the success or failure of any supplement especially if it was a placebo. If the athlete has total unconditional trust and respect for the third party and is told “take this - you will go faster ”it is more likely to work given the psychological bond in the relationship”. Similarly, another suggested: “I am sure that if I was told by [my coach] that should I drink XYZ before training that it would help with my performance, I am sure that what would really happen is that I would try harder and achieve a better result believing that this liquid had helped me”. |
Marketing |
The role of marketing in placebo effects was also alluded to by two participants (7%/4%), for example “…I believe that there are many products that are appealing to many people looking for short-cuts to fitness that do not have any scientific benefit but still work”, and: “Squash racket design technology has evolved significantly from the early 80's with the use of carbon fibre and graphite materials. Whenever a new design concept came out, the manufacturer (or sponsor) would encourage you to use the latest equipment to improve your performance. One year it was more strings closer together, the next it was less strings spaced further apart, the next year it was a different shaped frame. Whatever racket you used and you believed in it you could play better. If you went back to a 'old' design you were still able to play well”. |
Change in behaviour |
Three respondents (10%/6%) argued that the placebo effect was the result of a change in behaviour. For example “…I would probably try harder and achieve a better result believing that this liquid had helped me”, and “…I am not certain of how much this is due to the supplement or to the fact that subconsciously I am training harder”. |
Random fluctuation in performance |
One respondent (3%/2%) suggested that any change in performance associated with a purported placebo effect might in fact be the result of other mechanisms, suggesting “…this 'stronger' feeling could be attributed to better preparation and more rest.” |
ACKNOWLEDGEMENTS |
The author would like to acknowledge the help of Ms. Abigail Foad in the preparation of this manuscript. |
AUTHOR BIOGRAPHY |
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REFERENCES |
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