Effectiveness of High-Intensity Interval Training vs Moderate-Intensity Continuous Training in Patients With Fibromyalgia: A Pilot Randomized Controlled Trial

Abstract

Objective: To compare the effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) combined with strengthening and stretching exercises in patients with fibromyalgia.

Design: Interventional, single-blind, randomized controlled trial.

Setting: Outpatient rehabilitation center.

Participants: Women with fibromyalgia (N=60) were randomized to HIIT, MICT, and control groups.

Interventions: HIIT included a 5-minute warm-up at 50% of peak heart rate and 4 cycles of 4 minutes at 80%-95% of peak heart rate followed by 3-minute recovery intervals at 70% of peak heart rate. MICT consisted of 45 minutes at 65%-70% of peak heart rate. Each aerobic training session was followed by standardized strengthening and stretching exercises. The programs performed using cycle ergometers for 5 sessions per week for 6 weeks. The control group did not participate in any supervised exercise sessions.

Main outcome measures: The primary outcome measure was the Fibromyalgia Impact Questionnaire (FIQ). The secondary outcome measures were visual analog scale for pain, Short Form-36 Health Survey (SF-36), cardiopulmonary exercise test (CPET), and body composition parameters.

Results: Fifty-five participants completed the study. There was no significant difference in FIQ between HIIT vs MICT (1.03; 95% CI, -9.67 to 11.75) after treatment. Group-time interactions were significant for the FIQ between interventions and control (HIIT vs control, -16.20; 95% CI, -27.23 to -5.13 and MICT vs control, -17.24; 95% CI, -28.27 to -6.22) (all P<.001). There were significant group-time interactions for the pain, SF-36, and CPET parameters between treatments and control (all P<.05). Body weight, fat percentage, fat mass, and body mass index improved significantly (all P<.05) only in the MICT group after treatment.

Conclusions: The HIIT plus strengthening and stretching exercises and MICT plus strengthening and stretching exercises interventions showed significant improvements for the effect of fibromyalgia, pain degree, functional capacity, and quality of life compared with the control group. HIIT was not superior to MICT. Furthermore, body composition parameters were improved significantly only for the MICT group.

Trial registration: ClinicalTrials.gov NCT03924960.

Keywords: Cardiorespiratory fitness; Exercise; High-intensity interval training; Oxygen consumption; Rehabilitation.