We concur that a brief description of the literature regarding EIH in FM is warranted and have added information to the discussion as follows: “Previous research regarding the effects of acute bouts of exercise on pain sensitivity in FM patients is largely equivocal. Some studies have demonstrated a hypoalgesic effect [5,24] while other studies show either no changes in pain perception or an exacerbation of pain [25–27].”
However, the authors need to compare their findings to other research evidence showing impaired EIH and/or descending inhibition in patients with FM - especially considering that their results did not support EIH in the controls. The authors merely mention that the exercise stimulus may have been insufficient for the controls to show EIH without critically discussing what such a conclusion would mean (eg, FM patients have better EIH mechanisms than the controls).