title: A novel method for calculating the energy cost of turning during running.
abstract: Although changes of direction are one of the essential locomotor patterns in ball sports, the physiological demand of turning during running has not been previously investigated. We proposed a novel approach by which to evaluate the physiological demand of turning. The purposes of this study were to establish a method of measuring the energy expenditure (EE) of a 180° turn during running and to investigate the effect of two different running speeds on the EE of a 180° turn. Eleven young, male participants performed measurement sessions at two different running speeds (4.3 and 5.4 km/hour). Each measurement session consisted of five trials, and each trial had a different frequency of turns. At both running speeds, as the turn frequency increased the gross oxygen consumption (V·O2) also increased linearly (4.3 km/hour, r = 0.973; 5.4 km/hour, r = 0.996). The V·O2 of a turn at 5.4 km/hour (0.55 [SD 0.09] mL/kg) was higher than at 4.3 km/hour (0.34 [SD 0.13] mL/kg) (P < 0.001). We conclude that the gross V·O2 of running at a fixed speed with turns is proportional to turn frequency and that the EE of a turn is different at different running speeds. The Different Frequency Accumulation Method is a useful tool for assessing the physiological demands of complex locomotor activity.
authors.affiliation: Graduate School of Sports and Health Science, Fukuoka University, Nanakuma Jonan-ku Fukuoka, Japan.
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Hatamoto
authors.affiliation: The Fukuoka University Institute for Physical Activity, Nanakuma Jonan-ku Fukuoka, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Yamada
authors.affiliation: Faculty of Sports and Health Science, Fukuoka University, Nanakuma Jonan-ku Fukuoka, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Fujii
authors.affiliation: Faculty of Sports and Health Science, Fukuoka University, Nanakuma Jonan-ku Fukuoka, Japan.
authors.forename: Yasuki
authors.initials: Y
authors.lastname: Higaki
authors.affiliation: Faculty of Sports and Health Science, Fukuoka University, Nanakuma Jonan-ku Fukuoka, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Kiyonaga
authors.affiliation: Faculty of Sports and Health Science, Fukuoka University, Nanakuma Jonan-ku Fukuoka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Tanaka
keywords: V·O2; energy expenditure; heart rate; running speed; turn frequency; turning