Affiliations: [a] Department of Human Life System Design, Faculty of
Design, Kyushu University, Japan | [b] Department of Nutrition and Health Sciences, Faculty
of Nursing and Nutrition, Siebold University of Nagasaki, Japan
Note: [] Address for correspondence: Satoshi Muraki, Ph.D., Department of
Human Life System Design, Faculty of Design, Kyushu University, 4-9-1 Shiobaru,
Minamiku, Fukuoka 815-8540, Japan. Tel.: +81 92 553 4457; Fax: +81 92 553 4569;
E-mail: muraki@design.kyushu-u.ac.jp
Abstract: The purpose of this study was to investigate the influences of
pedaling rate during passive leg cycling (PLC) on respiratory and cardiac
responses in able-bodied subjects. Ten male and ten female subjects performed
PLC on an electric motor-controlled ergometer that provides constant-rate
pedaling. After PLC at 20 rpm for 5 min, the pedaling rate was gradually
increased by 5 rpm every 1 min until 70 rpm was attained. Gas exchange
responses, heart rate, and muscle oxygenation were measured during rest and
PLC. The increases in ventilation, oxygen uptake, and heart rate in both sexes
accelerated when the pedaling rate exceeded a threshold of between 20–45 rpm.
Over this threshold, they increased linearly, not exponentially. These results
suggest that respiratory and cardiac responses were influenced by the pedaling
rate during PLC and were promoted at a low pedaling rate.
