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Chhabra B, Szabo A. Placebo and Nocebo Effects on Sports and Exercise Performance: A Systematic Literature Review Update. Nutrients 2024; 16:1975. [PMID: 38999724 PMCID: PMC11243088 DOI: 10.3390/nu16131975] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2024] [Revised: 06/17/2024] [Accepted: 06/19/2024] [Indexed: 07/14/2024] Open
Abstract
Sports performance could be affected by placebo and nocebo effects. The last literature review on placebo and nocebo effects on sports and exercise performance was published in 2019. In the past five years, several new studies have been published. This review aimed to update the previous synthesis and evaluate the results of new studies focusing on placebo or nocebo interventions in sports and exercise by determining the form and magnitude of their effect. Hence, we searched for empirical studies published from 2019 until the end of May 2024 indexed in PubMed, Medline, Web of Science, EBSCO, and Google Scholar databases. The search yielded 20 eligible studies with control or baseline-control conditions, focusing on nutritional, mechanical, and other mixed ergogenic aids. They yielded small to large placebo effects (Cohen's d) for nutritional (d = 0.86), mechanical (d = 0.38), cream and gel (d = 0.05), and open-label placebo (d = 0.16) interventions. The pooled effect size for placebo effects was moderate to large (d = 0.67), larger than in the earlier review, suggesting that placebo effects can improve motor performance even more than previously reported. However, based on five measures from three studies, the nocebo effects were almost twice as large (d = 1.20). Accordingly, the current findings support and expand the last review in the field by yielding additional support for placebo and nocebo effects in sports and exercise.
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Affiliation(s)
- Bhavya Chhabra
- Institute of Health Promotion and Sport Sciences, Faculty of Psychology and Education, ELTE Eötvös Loránd University, 1075 Budapest, Hungary
- Doctoral School of Education, Faculty of Psychology and Education, ELTE Eötvös Loránd University, 1075 Budapest, Hungary
| | - Attila Szabo
- Faculty of Sport and Health Sciences, Széchenyi István University, 9025 Győr, Hungary
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Wang YB, Guo L, Fan JY, Mao ZX. Expectations Come True: The Placebo Effect of Exercise on Affective Responses. RESEARCH QUARTERLY FOR EXERCISE AND SPORT 2023; 94:1153-1161. [PMID: 36121715 DOI: 10.1080/02701367.2022.2121372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 08/24/2022] [Indexed: 06/15/2023]
Abstract
Objective: This study investigated the placebo and nocebo effects of habitual and induced expectations. Methods: In Study 1, 95 participants (Mage = 19.65 ± 2.21 years, MBMI = 21.94 ± 2.55) were grouped according to habitual expectations (positive, neutral, or negative) and completed a 30-min moderate-intensity aerobic exercise, and their affective response, rating of perceived exertion (RPE), and heart rate variability (HRV) were measured before, during, and after the exercise. In Study 2, the participants from Study 1 were grouped according to induced expectations (control, positive, or negative) and completed a 30-min moderate-intensity aerobic exercise. Affective response, RPE, and HRV were measured before, during, and after exercise. Results: In Study 1, positive habitual expectations increased affective response during and after exercise [F(2, 92) = 2.959, p = .057, ηp2 = .060], and negative habitual expectations increased RPE during exercise [F(2, 92) = 5.174, p = .007, ηp2 = .101]. In Study 2, positive induced expectation increased affective response during [F(2, 86) = 5.492, p = .006, ηp2 = .113] and after exercise [F(2, 86) = 6.096, p = .003, ηp2 = .124] and was not affected by habitual expectation. Conclusion: The affective response during and after exercise is influenced by habitual and induced expectations. Positive expectations enhance affective benefits, while negative expectations reduce affective benefits.
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Nasiri-Dehsorkhi H, Vaziri S, Esmaillzadeh A, Adibi P. Psychological distress, perceived stress and nocebo effect (multifood adverse reaction) in irritable bowel syndrome patients. JOURNAL OF EDUCATION AND HEALTH PROMOTION 2023; 12:257. [PMID: 37727431 PMCID: PMC10506782 DOI: 10.4103/jehp.jehp_221_23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 04/03/2023] [Indexed: 09/21/2023]
Abstract
BACKGROUND Psychological distress and perceived stress may complicate the clinical presentation, course, and treatment of patients with functional gastrointestinal disorders. The correlation between psychological distress, perceived stress, and the nocebo effect (multifood adverse reaction) in patients with irritable bowel syndrome (IBS) was the main aim of the present study. MATERIALS AND METHODS In this cross-sectional correlation study, data on 4,763 Iranian adults, 748 of whom by purposive sampling were patients with IBS (65.1% female), working in 50 different health centers affiliated to the Isfahan University of Medical Sciences across Isfahan province were examined. For assessing dietary intake, a 106-item self-administered Dish-based Semi-Quantitative Food Frequency Questionnaire that was specifically designed and validated for Iranian adults was used. General Heath Questionnaire 12 and Stressful Life event Questionnaire were used to assess psychological distress and perceived stress. By using a modified Persian version of the Rome III questionnaire, IBS was assessed. Based on researcher-made definition of nocebo effect (multiitem food intolerance), 164 people had the nocebo phenomenon in IBS group. RESULTS Age, sex, education, marital status, antidepressant use, and specifically chronic underlying disease (odds ratio [OR]: 3.54, 95% confidence interval [CI]: 1.73-7.23) of general characteristics had a significant correlation (P <.05) with presenting nocebo responses in IBS patients. Psychological distress (OR: 1.415; 95% CI: 0.992-2.020; P = 0.056) had a significant correlation with nocebo effect and did not find significant correlation with perceived stress (OR: 0.999; 95% CI: 0.990-1.008; P = 0.865). Data were analyzed by Chi-square test, analysis of variance, and OR. CONCLUSION The present study showed that psychological distress with chronic underlying disease and antidepressant use are important elements in presenting multifood adverse reactions that we named here as the nocebo effect in IBS patients. Reducing psychological distress and managing chronic underlying diseases appear to be an effective factor in reducing the nocebo phenomenon in IBS patients. For managing the nocebo responses in IBS patients, these findings may help clinicians to improve their interventions. Further studies are required to confirm these findings.
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Affiliation(s)
- Hamid Nasiri-Dehsorkhi
- Department of Clinical Psychology, Roudehen Branch, Islamic Azad University, Roudehen, Iran
- Isfahan Gastroenterology and Hepatology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Shahram Vaziri
- Department of Clinical Psychology, Roudehen Branch, Islamic Azad University, Roudehen, Iran
| | - Ahmad Esmaillzadeh
- Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Peyman Adibi
- Isfahan Gastroenterology and Hepatology Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
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Russell K, Duncan M, Price M, Mosewich A, Ellmers T, Hill M. A comparison of placebo and nocebo effects on objective and subjective postural stability: a double-edged sword? Front Hum Neurosci 2022; 16:967722. [PMID: 36061498 PMCID: PMC9434487 DOI: 10.3389/fnhum.2022.967722] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/25/2022] [Indexed: 11/15/2022] Open
Abstract
Background: Positive expectations (i.e., placebo effect) can improve postural control during quiet standing. This raises an important question: if postural control is susceptible to positive expectations, is it possible to elicit the opposite, a decline in postural stability, simply by suggesting a performance impairment (i.e., nocebo) will take place? Yet no studies have examined the nocebo effect on balance performance. To better understand both phenomena, comparative studies, which include both placebo and nocebo conditions, are needed. Method: Forty-two healthy adults were initially assessed for objective (center of pressure movement) and subjective (perceived) postural stability and performance expectations. Participants were then randomly assigned in equal numbers to a placebo (positive expectation), nocebo (negative expectation) or control (no suggestion) group. Participants in the placebo/nocebo groups were deceptively administered an inert capsule described as a potent supplement which would either positively or negatively influence their balance performance. Objective and subjective postural stability, and performance expectations were reassessed 20 min later. Results: The nocebo procedure evoked an increase in COP sway movements and reduced perceived stability compared to a control group. The placebo group presented with reductions COP sway movements and increased perceived stability following expectation manipulation. Compared to the control group, the placebo group showed a significantly higher performance expectation whilst the nocebo group showed a significantly lower performance expectation. Regression analyses also revealed that performance expectations following the placebo/nocebo procedure significantly predicted perceptions of postural instability (i.e., perceived performance), accounting for around 50% of the variance. These results remained even when controlling for actual performance (i.e., objective postural stability). Conclusion: Our findings indicate that positive and negative performance expectations evoked by instructional manipulation can profoundly influence both objective and subjective postural stability. Postural control—and perceptions regarding such—are clearly susceptible to expectation manipulation, which could have important practical implications and repercussions on testing, training interventions and rehabilitation programs. Positive and negative expectancies are a double-edged sword for postural control.
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Affiliation(s)
- Katherine Russell
- Centre for Sport, Exercise and Life Sciences, School of Life Sciences, Coventry University, Coventry, United Kingdom
| | - Michael Duncan
- Centre for Sport, Exercise and Life Sciences, School of Life Sciences, Coventry University, Coventry, United Kingdom
| | - Michael Price
- Centre for Sport, Exercise and Life Sciences, School of Life Sciences, Coventry University, Coventry, United Kingdom
| | - Amber Mosewich
- Faculty of Kinesiology, Sport, and Recreation, University of Alberta, Edmonton, AB, Canada
| | - Toby Ellmers
- Department of Brain Sciences, Imperial College London, London, United Kingdom
| | - Mathew Hill
- Centre for Sport, Exercise and Life Sciences, School of Life Sciences, Coventry University, Coventry, United Kingdom
- *Correspondence: Mathew Hill
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Horváth Á, Köteles F, Szabo A. Nocebo effects on motor performance: A systematic literature review. Scand J Psychol 2021; 62:665-674. [PMID: 34145580 DOI: 10.1111/sjop.12753] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 04/06/2021] [Accepted: 05/06/2021] [Indexed: 01/08/2023]
Abstract
Directionally opposite to placebo effects are the nocebo effects that negatively impact people's thoughts, feelings, and actions. An important but scarcely studied aspect of everyday functioning is motor performance, in which nocebo effects might impair athletic skills and the much-needed purposeful daily movements and motor actions. The aim of this literature review is to unveil the nocebo effects on motor performance. Searched databases were PubMed, PsycINFO, and SPORTDiscus. Twenty-one articles, reporting 23 studies, met the eligibility criteria for inclusion in the current review. All reports exhibited "some" risk of bias. Of the 23 studies, 14 found a nocebo effect on motor performance, equivocal results emerged from two studies, and negative findings were reported in seven studies. Most (10/12) studies using a between-subjects design have reported a nocebo effect. The mean effect size was 0.60, suggesting a medium-to-large effect of nocebo intervention on motor performance. Based on this review, we conclude that nocebo effects do influence motor performance and can be evoked with negative verbal information. This effect may be more robust than the placebo effect but also depends on the type of motor performance, on the examined sample, and on the nocebo agent. Hence, nocebo effects should be recognized and controlled in empirical research on motor performance, and they should be prevented or extinguished in practical and therapeutic settings. More extensive examination of the nocebo effect on motor performance is warranted, especially using between-subjects research design and a "no agent" control condition.
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Affiliation(s)
- Áron Horváth
- Doctoral School of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary.,Institute of Health Promotion and Sport Sciences, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Ferenc Köteles
- Institute of Health Promotion and Sport Sciences, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Attila Szabo
- Institute of Health Promotion and Sport Sciences, ELTE Eötvös Loránd University, Budapest, Hungary.,Institute of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary
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