exercise can improve muscle metabolism and pain through mitochondrial pathways. When comparing different exercise programs, aerobic exercise is capable of modulating the autonomic nervous function of fibromyalgia patients, whereas resistance exercise does not show such effects. A 2022 meta-analysis found that aerobic training showed a high effect size while strength interventions showed moderate effects. Meditative exercise seems preferable for improving sleep, with no differences between resistance, flexibility and aquatic exercise in their favorable effects on fatigue. Despite its benefits, exercise is a challenge for patients with fibromyalgia, due to the chronic fatigue and pain they experience. They perceive it as more effortful than healthy adults. Exercise may intimidate them, in fear that they will be asked to do more than they are capable of. They may also feel that those who recommend or deliver exercise interventions do not fully understand the possible negative impact of exercise on fatigue and pain. This is especially true for non-personalized exercise programs. Adherence is higher when the exercise program is recommended by doctors or supervised by nurses. Depression and higher pain intensity serve as barriers to physical activity. A recommended approach to a graded exercise program begins with small, frequent exercise periods and builds up from there. In order to reduce pain, it is recommended to use an exercise program of 13 to 24 weeks, with each session lasting 30 to 60 minutes. Aerobic Aerobic exercise for fibromyalgia patients is the most investigated type of exercise. It includes activities such as walking, jogging, spinning, cycling, dancing and exercising in water, with walking being named as one of the best methods. A 2017 cochrane summary concluded that aerobic exercise probably improves quality of life, slightly decreases pain and improves physical function and makes no difference in fatigue and stiffness. A 2019 meta-analysis showed that exercising aerobically can reduce autonomic dysfunction and increase heart rate variability. This happens when patients exercise at least twice a week, for 45–60 minutes at about 60%-80% of the maximum heart rate. Aerobic exercise also decreases anxiety and depression and improves the quality of life. Flexibility Combinations of different exercises such as flexibility and aerobic training may improve stiffness. However, the evidence is of low-quality. It is not clear if flexibility training alone compared to aerobic training is effective at reducing symptoms or has any adverse effects. Resistance In resistance exercise, participants apply a load to their body using weights, elastic