Elevated Perceived Exertion in People with Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and Fibromyalgia: A Meta-analysis.

Observed Findings

• People with ME/CFS and fibromyalgia reported significantly higher perceived exertion (large effect size of 0.85) during aerobic exercise compared to healthy controls.
• The magnitude of elevated perceived exertion was larger at peak exercise intensity compared to submaximal intensities.
• ME/CFS and fibromyalgia populations showed different patterns of perceived exertion, suggesting disease-specific mechanisms may contribute.
• The effect was consistent across 41 separate measurements from diverse study populations and protocols.
• This elevation in perceived exertion occurred despite comparable or similar physiological responses (heart rate) between patients and controls.

Inferred Conclusions

• The perception of exercise effort is genuinely altered in ME/CFS and fibromyalgia, rather than being a reporting bias or psychological artifact.
• Understanding the mechanisms driving elevated perceived exertion may illuminate core pathophysiological processes underlying these conditions.
• Further research into whether central nervous system signaling or peripheral biological signals drive this heightened perception is warranted.
• The discordance between perceived effort and objective physiological measures suggests investigation of interoceptive and nociceptive processing abnormalities could be fruitful.

Remaining Questions