- Background: The term chronic multi-symptom illness (CMI) refers to a spectrum of pain disorders, such as fibromyalgia and chronic fatigue syndrome, that are characterized by unexplained chronic pain, fatigue, and cognitive and mood complaints Objectives: To examine the hypothesis that exercise cessation is associated with symptoms similar to CMI in welltrained amateur athletes. methods: The study, conducted in running and triathlon clubs in Israel, involved 26 asymptomatic healthy athletes who regularly exercise 6.75 ± 3.65 hours a week. All athletes were instructed to refrain from physical activity for 7 days. All underwent a complete physical exam, rheumatological assessment including non-articular tenderness threshold (using dolorimeter) and tender points. In addition they completed the SF-36 quality of life questionnaire. Assessments were conducted before exercise cessation and 7 days later. results: Seven days after sports deprivation all subjects were significantly more tender by all tender measures (P < 0.001) (dolorimeter thresholds and tender point count). There was also a significant reduction in the scores for physical role function (P < 0.001), emotional role function (P < 0.001) and summary subscales of the SF-36 questionnaire after exercise cessation. conclusions: Exercise deprivation is associated with change in non-articular tenderness threshold and reduction in quality of life scores. This may be associated with the development of chronic multi-symptom illness.