Objectives: 

Together with widespread pain and allodynia, fibromyalgia syndrome is characterized by an altered inflammatory/stress status, and exercise is currently proposed as being a good therapeutic help for these patients. However, the mechanisms involved in the exercise-induced benefits are still poorly understood. The purpose of the present study was to evaluate the effect of a single bout of moderate cycling (45 min at 55% VO2 max) on the stress (cortisol; NA; and eHsp72) and the innate immune responses (chemotaxis and O2- production by neutrophils) in women diagnosed with FM compared with an aged-matched control group of healthy women (HW).

Materials: 

METHODS: Circulating concentrations of NA and eHsp72 were determined by ELISA. Cortisol was determined by electrochemoluminiscence, chemotaxis was evaluated in Boyden chambers and O2- production by NBT reduction.

Results: 

Paradoxically, in the FM patients the exercise induced a decrease in the systemic concentration of cortisol, NA, and eHsp72, as well as in the neutrophils' chemotaxis and O2- production. This was contrary to the expected exercise-induced increase in all those biomarkers in HW.

Conclusions: 

Single sessions of moderate cycling improve the inflammatory and stress status in FM patients, reaching values close to the situation of aged-matched HW at their basal status. These results show that responses to exercise could differ according to each individual's particular set-point, and that, as a novel finding of the present study, even though two individuals might show opposite responses, these responses may each be working in a positive direction.

This work has been supported by grants from MICINN-FEDER (DEP2009-10041) of Spain and Junta de Extremadura-FEDER (PRI09A003 and GR10020).