Daily physical activity of patients with the chronic fatigue syndrome: a systematic review

Objective: To give an overview of the physical activity level of patients with chronic fatigue syndrome in comparison with asymptomatic controls. Data sources: MEDLINE, Web of Science, EMBASE, PsycINFO, Picarta, the Cochrane Controlled Trial Register that is included in the Cochrane Library and reference tracking. Review methods: A systematic literature search was conducted focusing on studies concerning physical activity levels of patients with chronic fatigue syndrome compared to controls. A meta-analysis was performed to pool data of the studies. Results: Seventeen studies were included with 22 different comparisons between patients with chronic fatigue syndrome and controls. Fourteen studies, including 18 comparisons, showed lower physical activity levels in patients with chronic fatigue syndrome as compared to controls. Four studies, including four comparisons, showed no differences between both groups. The meta-analysis included seven studies and showed a daily physical activity level in patients with chronic fatigue syndrome of only 68% of the physical activity level observed in control subjects. The pooled mean coefficient of variation in patients with chronic fatigue syndrome was higher as compared to control subjects (34.3% versus 31.5%), but this difference did not reach significance. Conclusion: Patients with chronic fatigue syndrome appear to be less physically active compared with asymptomatic controls. There is no difference in variation of physical activity levels between patients with chronic fatigue syndrome and healthy control subjects, but the validity and reliability of some methods of measuring physical activity is questionable or unknown.