title: Importance, Reliability, and Usefulness of Acceleration Measures in Team Sports.
abstract: Delaney, JA, Cummins, CJ, Thornton, HR, and Duthie, GM. Importance, reliability and usefulness of acceleration measures in team sports. J Strength Cond Res 32(12): 3494-3502, 2018-The ability to accelerate, decelerate, and change direction efficiently is imperative to successful team sports performance. Traditional intensity-based thresholds for acceleration and deceleration may be inappropriate for time-series data and have been shown to exhibit poor reliability, suggesting other techniques may be preferable. This study assessed movement data from one professional rugby league team throughout 2 full seasons and 1 preseason period. Using both 5 and 10 Hz global positioning systems (GPS) units, a range of acceleration-based variables were evaluated for their interunit reliability, ability to discriminate between positions, and associations with perceived muscle soreness. The reliability of 5 Hz global positioning systems for measuring acceleration and deceleration ranged from good to poor (CV = 3.7-27.1%), with the exception of high-intensity deceleration efforts (CV = 11.1-11.8%), the 10 Hz units exhibited moderate-to-good interunit reliability (CV = 1.2-6.9%). Reliability of average metrics (average acceleration/deceleration, average acceleration, and average deceleration) ranged from good to moderate (CV = 1.2-6.5%). Substantial differences were detected between positions using time spent accelerating and decelerating for all magnitudes, but these differences were less clear when considering the count or distance above acceleration/deceleration thresholds. All average metrics detected substantial differences between positions. All measures were similarly related to perceived muscle soreness, with the exception of high-intensity acceleration and deceleration counts. This study has proposed that averaging the acceleration/deceleration demands over an activity may be a more appropriate method compared with threshold-based methods, because a greater reliability between units, while not sacrificing sensitivity to within-subject and between-subject changes.
authors.affiliation: Newcastle Knights Rugby League Club, Mayfield, New South Wales, Australia.|Institute of Sport Exercise and Active Living, Victoria University, Footscray Campus, Melbourne, Victoria, Australia.
authors.forename: Jace A
authors.initials: JA
authors.lastname: Delaney
authors.affiliation: School of Science and Technology, University of New England, Armidale, New South Wales, Australia.
authors.forename: Cloe J
authors.initials: CJ
authors.lastname: Cummins
authors.affiliation: Newcastle Knights Rugby League Club, Mayfield, New South Wales, Australia.|La Trobe Sport and Exercise Medicine Research Center, La Trobe University Bundoora Campus, Melbourne, Victoria, Australia.
authors.forename: Heidi R
authors.initials: HR
authors.lastname: Thornton
authors.affiliation: School of Exercise Science, Australian Catholic University, Strathfield, New South Wales, Australia.
authors.forename: Grant M
authors.initials: GM
authors.lastname: Duthie
mesh_terms: D000054:Acceleration; D000293:Adolescent; D000328:Adult; D056352:Athletes; D054874:Athletic Performance; D003654:Deceleration; D005538:Football; D040362:Geographic Information Systems / Q000295:instrumentation*; D006801:Humans; D008297:Male; D009068:Movement; D015203:Reproducibility of Results; D012420:Running; D055815:Young Adult