title: Does degree of alteration in effort sense caused by eccentric exercise significantly affect initial exercise hyperpnea in humans?
abstract: Previous research has shown an exaggeration in exercise hyperpnea 2 days after eccentric exercise (ECC). Enhancement in central command has been suggested as one candidate to account for this effect given that ECC-induced neuromuscular dysfunction increases relative exercise intensity, thus resulting in reinforcement of effort sense. The purpose of this study was, therefore, to elucidate whether the degree of alteration in effort sense caused by ECC affects exercise hyperpnea. Ten subjects performed 20-s single-arm extension-flexion exercises with weight strapped to the wrist, and ventilatory response was measured before (Pre) and 2 days after ECC (D2). Relative exercise intensity at Pre was 5 % of maximal voluntary contraction (MVC) of Pre, whereas that at D2 was 9 % MVC of D2 because of decline in muscle strength. Ventilatory responses were significantly exaggerated at D2 with a significant increase in effort sense. Although effort sense was significantly reduced during exercise at D2 when wrist weight was subtracted to match relative exercise intensity at Pre (5 % MVC of D2), ventilatory responses were still significantly higher than those of Pre. After the disappearance of post-ECC muscle damage, subjects performed the same exercise with weight added (9 % MVC of Pre) so that effort was equalized to match that of D2; however, no significant increase in ventilatory response was detected. The fact that the extent of change in effort sense caused by ECC-induced neuromuscular dysfunction did not affect ventilatory response at the onset of exercise after ECC may suggest that the exaggeration of ventilatory response after ECC is caused by mechanisms other than alteration of the central command.
authors: College of Life and Health Sciences, Chubu University, Kasugai, Aichi, 487-8501, Japan. horinori@isc.chubu.ac.jp.
authors: Norio
authors: http://orcid.org/0000-0002-3039-5934
authors: N
authors: Hotta
authors: Faculty of Human Health Sciences, Meio University, Nago, Okinawa, Japan.
authors: Kaoru
authors: K
authors: Yamamoto
authors: College of Life and Health Sciences, Chubu University, Kasugai, Aichi, 487-8501, Japan.
authors: Hisayoshi
authors: H
authors: Ogata
authors: Morioka Junior College, Department of International Cultural Studies, Iwate Prefectural University, Takizawa, Iwate, Japan.
authors: Patrick
authors: P
authors: Maher
authors: Graduate School of Life and Health Sciences, Chubu University, Kasugai, Aichi, Japan.
authors: Naoya
authors: N
authors: Okumura
authors: Research Center of Health, Physical Fitness and Sports, Nagoya University, Nagoya, Aichi, Japan.
authors: Koji
authors: K
authors: Ishida
mesh_terms: D000293:Adolescent; D000328:Adult; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D005082:Physical Exertion / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology; D012143:Respiratory Physiological Phenomena; D055815:Young Adult
keywords: Central command; Delayed onset muscle soreness; Exercise onset; Neuromuscular dysfunction; Ventilation