title: Impact of Center-of-Mass Acceleration on the Performance of Ultramarathon Runners.
abstract: Ultramarathon races are rapidly gaining popularity in several countries, raising interest for the improvement of training programs. The aim of this study was to use a triaxial accelerometer to compare the three-dimensional center-of-mass accelerations of two groups of ultramarathon runners with distinct performances during different running speeds and distances. Ten runners who participated in the 12-h Taipei International Ultramarathon Race underwent laboratory treadmill testing one month later. They were divided into an elite group (EG; n = 5) and a sub-elite group (SG; n = 5). The triaxial center-of-mass acceleration recorded during a level-surface progressive intensity running protocol (3, 6, 8, 9, 10, and 12 km/h; 5 min each) was used for correlation analyses with running distance during the ultramarathon. The EG showed negative correlations between mediolateral (ML) acceleration (r = -0.83 to -0.93, p < 0.05), and between anterior-posterior (AP) acceleration and running distance (r = -0.8953 to -0.9653, p < 0.05), but not for vertical control of the center of mass. This study suggests that runners reduce stride length to minimize mediolateral sway and the effects of braking on the trunk; moreover, cadence must be increased to reduce braking effects and enhance impetus. Consequently, the competition level of ultramarathons can be elevated.
authors.affiliation: Center for General Education, China University of Science and Technology, Taipei, Taiwan. ; Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Shun-Ping
authors.initials: SP
authors.lastname: Lin
authors.affiliation: Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Wen-Hsu
authors.initials: WH
authors.lastname: Sung
authors.affiliation: Department of Computer Science & Information Management, Soochow University, Taipei, Taiwan.
authors.forename: Fon-Chu
authors.initials: FC
authors.lastname: Kuo
authors.affiliation: Institute of Brain Science, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Terry B J
authors.initials: TB
authors.lastname: Kuo
authors.affiliation: Department of Physical Therapy and Assistive Technology, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Jin-Jong
authors.initials: JJ
authors.lastname: Chen
keywords: accelerometer; race distance, ultra-marathon