- 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 To examine the hypothesis that exercise cessation is associated with symptoms similar to CMI in well-trained amateur athletes. 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. 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. 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.