Dosage of resistance exercises in fibromyalgia: evidence synthesis for a systematic literature review up-date and meta-analysis

Several studies have examined the effect of different types of exercise on people with fibromyalgia. The aim of this study was to identify which dosage of resistance training is effective to reduce pain in women with fibromyalgia. Two authors independently selected studies included in a Cochrane Systematic Review and from an updated search up to May 2021 using the following databases: Embase, Central, Lilacs, PEDro, Current Controlled Trials, and WHO International Clinical Trials Registry Platform, Scopus and ISI Web of Science. Inclusion criteria were randomized clinical trials (RCTs) with female patients (18 years of age or older) diagnosed with fibromyalgia according to the American College of Rheumatology (ACR) criteria and the intervention, resistance exercises for pain reduction. The pain outcome value was extracted from studies for meta-analysis. Nine RCTs were included. Compared to the control groups, resistance exercise groups demonstrated a clinically and statistically significant effect on pain reduction when each exercise was performed in 1–2 sets or 3–5 sets of 4–12 or 5–20 repetitions twice a week, for 8–12 weeks, at intensities of 40–80% with one repetition maximum or perceived exertion. Resistance training exercises are effective to reduce pain in women with fibromyalgia when performed at moderate-to-high intensity in 1–2 sets of 4–20 repetitions twice a week, for 8–12 weeks. The protocol was registered on the International Prospective Register of Systematic Reviews (PROSPERO) platform, CRD42018095205.