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.

Exercise addiction is widely studied, but an official clinical diagnosis does not exist for this behavioral addiction. Earlier research using various screening instruments examined the absolute scale values while investigating the disorder. The Exercise Addiction Inventory-3 (EAI-3) was recently developed with two subscales, one denoting health-relevant exercise and the other addictive tendencies. The latter has different cutoff values for leisure exercisers and elite athletes. Therefore, the present 15-country study (n = 3,760) used the EAI-3 to classify the risk of exercise addiction (REA), but only if the participant reported having had a negative exercise-related experience. Based on this classification, the prevalence of REA was 9.5% in the sample. No sex differences, and few cross-national differences were found. However, collectivist countries reported greater REA in various exercise contexts than individualist countries. Moreover, the REA among athletes was (i) twice as high as leisure exercisers, (ii) higher in organized than self-planned exercises, irrespective of athletic status, and (iii) higher among those who exercised for skill/mastery reasons than for health and social reasons, again irrespective of athletic status. Eating disorders were more frequent among REA-affected individuals than in the rest of the sample. These results do not align with recent theoretical arguments claiming that exercise addiction is unlikely to be fostered in organized sports. The present study questions the current research framework for understanding exercise addiction and offers a new alternative to segregate self-harming exercise from passionate overindulgence in athletic life.