摘要:The purpose of this study was to determine the effect of peripheral fatigue on temporal properties of mental imagery among unskilled and skilled swimmers. To this end, 30 male swimmers (15 skilled and 15 unskilled) in age range of 18 to 24 years old were randomly selected and their imagery duration (internal visual, external visual, kinesthetic) in the 100 meters front crawl before and after peripheral fatigue (free style swimming exercise with 70% of maximum heart rate intensity until exhaustion) were measured. The data were analyzed using mixed Anova at 95% confidence level. Based on the results, imagery accuracy of skilled athletes was higher than unskilled and timing error in kinesthetic imagery was more than visual imagery. The fatigue enhanced timing error for all three imagery types and both unskilled and skilled groups. Conclusion is that controlling of imagery timing in fatigue condition is necessary for interventions’ effectiveness.