title: The effects of inspiratory muscle training on plasma interleukin-6 concentration during cycling exercise and a volitional mimic of the exercise hyperpnea.
abstract: It is unknown whether the respiratory muscles contribute to exercise-induced increases in plasma interleukin-6 (IL-6) concentration, if this is related to diaphragm fatigue, and whether inspiratory muscle training (IMT) attenuates the plasma IL-6 response to whole body exercise and/or a volitional mimic of the exercise hyperpnea. Twelve healthy males were divided equally into an IMT or placebo (PLA) group, and before and after a 6-wk intervention they undertook, on separate days, 1 h of 1) passive rest, 2) cycling exercise at estimated maximal lactate steady state power (EX), and 3) volitional hyperpnea at rest, which mimicked the breathing and respiratory muscle recruitment patterns achieved during EX (HYPEX). Plasma IL-6 concentration remained unchanged during passive rest. The plasma IL-6 response to EX was reduced following IMT (main effect of intervention, P = 0.039) but not PLA (P = 0.272). Plasma IL-6 concentration increased during HYPEX (main effect of time, P < 0.01) and was unchanged postintervention. There was no evidence of diaphragm fatigue (measured by phrenic nerve stimulation) following each trial. In conclusion, plasma IL-6 concentration is increased during EX and HYPEX and this occurred in the absence of diaphragm fatigue. Furthermore, IMT reduced the plasma IL-6 response to EX but not HYPEX. These findings suggest that the respiratory muscles contribute to exercise-induced increases in plasma IL-6 concentration in the absence of diaphragm fatigue and that IMT can reduce the magnitude of the response to exercise but not a volitional mimic of the exercise hyperpnea.
authors.affiliation: Sport, Health and Performance Enhancement (SHAPEResearch Group, School of Science and Technology, Nottingham Trent University, Nottingham, United Kingdom.
authors.forename: Dean E
authors.initials: DE
authors.lastname: Mills
authors.forename: Michael A
authors.initials: MA
authors.lastname: Johnson
authors.forename: Martin J
authors.initials: MJ
authors.lastname: McPhilimey
authors.forename: Neil C
authors.initials: NC
authors.lastname: Williams
authors.forename: Javier T
authors.initials: JT
authors.lastname: Gonzalez
authors.forename: Yvonne A
authors.initials: YA
authors.lastname: Barnett
authors.forename: Graham R
authors.initials: GR
authors.lastname: Sharpe
mesh_terms: D000328:Adult; D001642:Bicycling; D015415:Biomarkers / Q000097:blood; D001945:Breathing Exercises; D003964:Diaphragm / Q000294:innervation / Q000378:metabolism* / Q000503:physiopathology; D004558:Electric Stimulation; D015444:Exercise; D006801:Humans; D006935:Hypercapnia / Q000097:blood* / Q000503:physiopathology; D001239:Inhalation; D015850:Interleukin-6 / Q000097:blood*; D019344:Lactic Acid / Q000097:blood; D008297:Male; D018763:Muscle Fatigue; D010465:Perception; D010791:Phrenic Nerve / Q000503:physiopathology; D011312:Pressure; D056152:Respiratory Rate; D013997:Time Factors; D014836:Volition; D055815:Young Adult
chemical_list: D015415:Biomarkers; C508600:IL6 protein, human; D015850:Interleukin-6; D019344:Lactic Acid
keywords: diaphragm fatigue; exercise; inspiratory muscle training; interleukin-6; respiratory muscles