Rocha, JoãoSerrano, JoãoLópez-SierraIbáñez, Sergio2025-10-172025-10-172025ROCHA, J. [et al.] (2025) -Profiling external load in U14 basketball: Cluster analysis of competition performance using inertial devices. Applied Sciences. 15(15), 8616. DOI: 10.3390/app15158616http://hdl.handle.net/10400.11/10334This study was conducted in accordance with the Declaration of Helsinki and approved by the University’s Ethics Committee (n.º 131/2024, approval date: 29 March 2024).Physical performance data is essential for planning youth training effectively; however, there is a lack of scientific information regarding performance in youth competitions. To address this gap, an innovative study was conducted with Portuguese U14 regional selections. Each player was equipped with a WimuPro™ inertial device. Six variables were considered: accelerations, decelerations, speed, player load, impacts, and high impacts. The objective of this study, based on data from official competitions, was to statistically analyze the distribution and intensity thresholds of six physical performance variables across five defined zones. A cluster k-means analysis was performed for a significance value of p < 0.05. Five zones were identified for all variables: acceleration [<0.37; 0.37 to 0.81; 0.81 to 1.54; 1.54 to 3.49; >3.49 m/s2], deceleration [<−0.26; −0.27 to −0.63; −0.63 to −1.22; −1.22 to −2.545; >−2.54 m/s2], speed [<5.42; 5.42 to 10.19; 10.20 to 14.63; 14.64 to 18.59; >18.59 km/h2], player load [<1.07; 1.07 to 1.36; 1.37 to 1.63; 1.64 to 1.95; >1.95 u.a./min], impacts [<133.45; 133.45 to 158.75; 158.76 to 181.45; 181.46 to 206.59; >206.59 cont/min], and high impacts [<1.13; 1.14 to 2.11; 2.12 to 3.13; 3.14 to 4.42; >4.42 cont/min]. These intensity zones should be taken into account to optimize training and enhance the understanding of competition in U14 basketball.engexternal loadPortuguese youth basketballinertial measurement unitscluster analysisperformance metricsjournal article10.3390/app151586163617-B345-B619