van den Tillaar, RolandUthoff, Aaron2026-04-172026-04-172024-11-13Sports Biomechanics, ISSN: 1476-3141 (Print); 1752-6116 (Online), Taylor and Francis Group, 25(2), 199-213. doi: 10.1080/14763141.2024.24276921476-31411752-6116http://hdl.handle.net/10292/20941This study examined the acute effects of different loading protocols on 180° change of direction (COD) performance in eleven male handball players. Participants performed a 10-0-5 COD test under seven conditions: without an external load, and with 3, 6, and 9 kg loads applied under two modes-assisted into the COD and resisted out of it and resisted into the COD and assisted out of it. While total COD time was not affected (p = 0.098; η2 = 0.16), significant phase effects were observed (p < 0.001; η2 ≥ 0.55). Loading protocols significantly influenced velocity, acceleration, and their distances from COD (p < 0.001; η2 ≥ 0.37). Significant phase effects were observed for all step kinematic variables (p ≤ 0.037; η2 ≥ 0.67), except contact time, and significant interaction (phase*condition) effects for all variables (p ≤ 0.004; η2 ≥ 0.08), except for step frequency. Assisted-resisted protocols increased deceleration demands through higher COD entry velocities, displaying fewer but longer steps in the acceleration phase and greater steps taken during the deceleration phase. Resisted-assisted protocols decreased deceleration demands due to lower COD entry velocities, displaying shorter, but more steps taken in the acceleration phase, and fewer steps taken in the deceleration phase. These findings suggest that assisted-resisted and resisted-assisted loading protocols can be used to selectively overload specific phases of COD performance.© 2024 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/by-nc-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.Assisted sprintingCODDynaspeedresisted sprintsstep kinematics42 Health Sciences4207 Sports Science and Exercise0913 Mechanical Engineering1106 Human Movement and Sports Sciences1303 Specialist Studies in EducationSport Sciences3202 Clinical sciences4207 Sports science and exerciseHumansBiomechanical PhenomenaMaleAccelerationYoung AdultAthletic PerformanceDecelerationWeight-BearingMotor SkillsAdultResistance TrainingHumansMotor SkillsWeight-BearingAccelerationDecelerationAdultMaleAthletic PerformanceResistance TrainingYoung AdultBiomechanical PhenomenaHumansBiomechanical PhenomenaMaleAccelerationYoung AdultAthletic PerformanceDecelerationWeight-BearingMotor SkillsAdultResistance TrainingJournal ArticleOpenAccess10.1080/14763141.2024.2427692