Imagery, a classic technique in psychological training, is gaining momentum in competitive sports. Despite the increasing use of imagery, its effectiveness remains debated. Robust, data-driven conclusions are still lacking. This study seeks to investigate the effects of imagery practice on enhancing athletic performance and determine the ideal dosage of such practice through a systematic review and multilevel meta-analysis. A comprehensive search across seven databases, including SportDiscus, PubMed, PsycINFO, Web of Science, MEDLINE, MEDLINE Complete, and CINAHL, yielded 23,027 studies. These were initially reviewed for title and abstract using ASReview, followed by full-text screening with Covidence. A total of 86 studies with 3593 athletes (2104 males and 1110 females) were included in this meta-analysis. Our findings indicate that imagery practice enhances athletic performance, encompassing agility, muscle strength, tennis and soccer performance, and is applicable to both tennis and soccer athletes. The efficacy of integrating imagery practice with one or two additional psychological skills trainings (PSTs) surpasses that of imagery practice in isolation. Moderation analysis revealed that engaging in imagery practice for approximately ten minutes, three times weekly over a span of one hundred days, produces the strongest performance gains. This review offers recommendations for athletes regarding the implementation of imagery practice in routine training or prior to competitions, thereby providing empirical evidence to optimize psychological training programs in competitive settings.

Background: An ambient-temperature eligibility criterion of ≥22 °C was treated as an operational lower boundary spanning moderate or mildly warm to hot conditions, not as a universal physiological threshold for heat stress. This systematic review and three-level meta-analysis evaluated acute carbohydrate–electrolyte (CHO-E) supplementation versus a water or non-caloric placebo during exercise at these temperatures. Methods: Following PROSPERO registration (CRD420261410953), five databases were searched to May 2026 for randomized controlled trials. Nested effect sizes were synthesized using three-level random-effects models (Hedges’ g), and certainty was evaluated with RoB 2 and GRADE. Results: A secondary omnibus synthesis included 32 effect sizes from 21 studies (N = 316) and yielded a small positive average estimate (g = 0.37, 95% CI: 0.21 to 0.53; p < 0.001; I² = 46.7%), although the 95% prediction interval crossed the null (−0.21 to 0.96). Primary outcome-domain analysis identified a positive average estimate for aerobic endurance (g = 0.45, 95% CI: 0.26 to 0.64), whereas evidence for anaerobic endurance, explosive power, and strength remained inconclusive. Post hoc threshold sensitivity analyses retained positive mean estimates after excluding trials at 22–25 °C (>25 °C: g = 0.41, 95% CI: 0.23 to 0.59) and at ≥28 °C (g = 0.36, 95% CI: 0.11 to 0.61), but both prediction intervals crossed zero. Neither ambient temperature nor exposure duration was a significant linear moderator. Conclusions: Acute CHO-E supplementation was associated with a small average performance difference, concentrated in aerobic endurance, within the specified ambient-temperature range. Because the trials compared treatments within the same environmental condition rather than hot with thermoneutral exercise, these results do not establish that CHO-E offsets heat-induced performance decrements.

Psychological skills training (PST) has been reported to produce beneficial effects on athletes (Birrer & Morgan, 2010; Brown & Fletcher, 2017). Existing studies have examined PST in relation to se...