Placebo and Nocebo Effects on Sports and Exercise Performance: A Systematic Literature Review Update.

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 in team sports: A systematic literature review.

While regular exercise should be part of the contemporary lifestyle, many people overindulge in it to the point of losing control over their behavior. This condition is known as exercise addiction (EA). Although addiction is an individual phenomenon, and most of the over 1,000 published studies on EA look at individual exercisers, there are studies on team sports athletes, too. Theoretically, these athletes should not manifest exercise addiction, but some studies are projecting the contrary. Therefore, in this literature review, we analyze EA in team athletes. Based on four databases (PsycINFO, SPORTDiscus, Web of Science, and Google Scholar), we located 22 articles conforming to inclusion criteria. These studies suggest a high risk of exercise addiction among team sports participants. While the figures are lower than for individual exercisers, they are in discord with the concept of addiction as a dysfunction, and the lack of a single case of exercise addiction reported (to date) in team sports athletes in the academic literature. In agreement with a recent position paper, we conclude that there are substantial conceptual and measurement errors in exercise addiction research.