Eccentric exercise augments the cardiovascular response to static exercise.
High-force eccentric exercise induces neuromuscular dysfunction and may augment the cardiovascular response to exercise. This investigation sought to determine whether changes in strength and sense of force following high-force eccentric exercise alter heart rate and blood pressure responses during isometric contractions. Subjects (4F,6M) performed 50 maximum resistance eccentric actions with one arm (ECC arm). Contractions at 10% of the ECC arm maximum were held for 7 min on two pre-exercise days. The force output perceived to be the same as 10% of the pre-exercise maximum was determined using a force matching task. This force, 35.6, 27.2, and 21.1% lower on days 1, 3, and 5 post-exercise, was held during isometric contractions on these days, respectively. Despite a lowering of absolute contraction force, heart rate (P < 0.05) and blood pressure (P < 0.001) responses during contractions using the ECC arm were consistently elevated relative to the control arm. However, subjects perceived that they were exerting forces similar to those achieved before eccentric exercise-induced neuromuscular dysfunction. These findings suggest that perceived effort following strength loss induced by mechanically stressful exercise dictates the cardiovascular responses during isometric contractions.
Miles
M P
MP
Department of Exercise Science, University of Massachusetts, Amherst 01003, USA. mxm58@psuvm.psu.edu
Li
Y
Y
Rinard
J P
JP
Clarkson
P M
PM
Williamson
J W
JW
D000293:Adolescent; D000328:Adult; D001794:Blood Pressure / Q000502:physiology*; D004562:Electrocardiography; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005260:Female; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction; D008297:Male; D018908:Muscle Weakness / Q000503:physiopathology*; D011434:Proprioception