TY - JOUR
T1 - Electrical activity of the diaphragm during progressive cycling exercise in endurance-trained men
AU - Poulsen, Mathias Krogh
AU - Thomsen, Lars Pilegaard
AU - Mifsud, Nicolai Lees
AU - Nielsen, Niels-Peter Brøchner
AU - Jørgensen, René Melvad
AU - Kjærgaard, Søren
AU - Karbing, Dan Stieper
PY - 2015/1/1
Y1 - 2015/1/1
N2 - The study aimed to investigate diaphragm respiratory drive modulation through electrical activity of the diaphragm (EADi) during progressive cycling in endurance-trained men (N= 7) and to test day-to-day measurement reliability. Normalized EADi increased at exercise intensities from 40% workload (WL) to 70% and 85%WL but plateaued from 70% to 85% (p<. 0.05). VO
2, VCO
2, VE, increased at all exercise intensities, where Vt and BF increased from 40% to 55% WL and from 70% to 85% and RER increased at 70% and 85% (p<. 0.05). Bland-Altman plots of normalized EADi showed bias of 0.9% and -6.4% and limits of agreement of ±36.0% and ±30.4% for absolute measurements and relative changes from 40% WL, respectively. Within-day variability appeared constant indicating that measurements within a trial are reliable. Results suggest that diaphragm respiratory drive increases at moderate exercise intensities, but plateaus at high intensities where other respiratory muscles might contribute significantly to the breathing effort, perhaps to "protect" against diaphragm fatigue.
AB - The study aimed to investigate diaphragm respiratory drive modulation through electrical activity of the diaphragm (EADi) during progressive cycling in endurance-trained men (N= 7) and to test day-to-day measurement reliability. Normalized EADi increased at exercise intensities from 40% workload (WL) to 70% and 85%WL but plateaued from 70% to 85% (p<. 0.05). VO
2, VCO
2, VE, increased at all exercise intensities, where Vt and BF increased from 40% to 55% WL and from 70% to 85% and RER increased at 70% and 85% (p<. 0.05). Bland-Altman plots of normalized EADi showed bias of 0.9% and -6.4% and limits of agreement of ±36.0% and ±30.4% for absolute measurements and relative changes from 40% WL, respectively. Within-day variability appeared constant indicating that measurements within a trial are reliable. Results suggest that diaphragm respiratory drive increases at moderate exercise intensities, but plateaus at high intensities where other respiratory muscles might contribute significantly to the breathing effort, perhaps to "protect" against diaphragm fatigue.
KW - Electromyography
KW - Bicycling
KW - Diaphragm/physiology
KW - Exercise/physiology
KW - Muscle Fatigue
KW - Physical Endurance/physiology
KW - Respiratory Physiological Phenomena
KW - Respiratory
KW - Progressive
KW - Exercise
KW - Drive
KW - Diaphragm
KW - Reliability
U2 - 10.1016/j.resp.2014.10.012
DO - 10.1016/j.resp.2014.10.012
M3 - Journal article
C2 - 25448397
VL - 205
SP - 77
EP - 83
JO - Respiratory Physiology & Neurobiology
JF - Respiratory Physiology & Neurobiology
SN - 1569-9048
ER -