This review is an update of a previous Cochrane review from 2004, which showed that exercise therapy was a promising treatment for adults with CFS. Since the review, additional studies investigating the effectiveness and safety of exercise therapy for patients with CFS have been published.
What questions does this review aim to answer?
• Is exercise therapy more effective than ‘passive’ treatments (e.g. waiting list, treatment as usual, relaxation, flexibility)?
• Is exercise therapy more effective than other ‘active’ therapies (e.g. cognitive-behavioural therapy (CBT), pacing, medication)?
• Is exercise therapy more effective when combined with another treatment than when given alone?
• Is exercise therapy safer than other treatments?
Which studies were included in the review?
We searched databases to find all high-quality studies of exercise therapy for CFS published up to May 2014. To be included in the review, studies had to be randomised controlled trials and include adults over 18 years of age, more than 90% of whom had a clear diagnosis of CFS. We included eight studies with a total of 1518 participants in the review. Seven studies used aerobic exercise therapy such as walking, swimming, cycling or dancing; the remaining study used non-aerobic exercise. Most studies asked participants to exercise at home, between three and five times per week, with a target duration of 5 to 15 minutes per session using different means of incrementation.
What does evidence from the review tell us?
Moderate-quality evidence showed exercise therapy was more effective at reducing fatigue compared to ‘passive’ treatment or no treatment. Exercise therapy had a positive effect on people’s daily physical functioning, sleep and self-ratings of overall health.
One study suggests that exercise therapy was more effective than pacing strategies for reducing fatigue. However exercise therapy was no more effective than CBT.
Exercise therapy did not worsen symptoms for people with CFS. Serious side effects were rare in all groups, but limited information makes it difficult to draw firm conclusions about the safety of exercise therapy.
Evidence was not sufficient to show effects of exercise therapy on pain, use of other healthcare services, or to allow assessment of rates of drop-out from exercise therapy programmes.
What should happen next?
Researchers suggest that further studies should be carried out to discover what type of exercise is most beneficial for people affected by CFS, which intensity is best, the optimal length, as well as the most beneficial delivery method.
Patients with CFS may generally benefit and feel less fatigued following exercise therapy, and no evidence suggests that exercise therapy may worsen outcomes. A positive effect with respect to sleep, physical function and self-perceived general health has been observed, but no conclusions for the outcomes of pain, quality of life, anxiety, depression, drop-out rate and health service resources were possible. The effectiveness of exercise therapy seems greater than that of pacing but similar to that of CBT. Randomised trials with low risk of bias are needed to investigate the type, duration and intensity of the most beneficial exercise intervention.