Testing procedures
All testing was carried out by the first author and took place in gymnasiums across two sites used by the respective basketball clubs for regular practice. Testing took place one week before and after the eight-week intervention period and included: anthropometry (height, seated height, mass), overhead squat (OHS) assessment, countermovement jump (CMJ), 10-m sprint and, for the experimental groups only, a parkour speed-run. To estimate participant maturity status, anthropometric measures were recorded using medical grade digital scales and stadiometer (Seca, Birmingham, United Kingdom) and entered into a sex-specific equation to predict maturity offset [Girls: Maturity Offset (years) = -9.376 + (0.0001882 x (leg length x sitting height)) + (0.0022 x (age x leg length)) + (0.005841 x (age x sitting height))–(0.002658 x (age x mass)) + (0.07693 x (mass by stature ratio x 100));andBoys: Maturity offset (years) = -9.236 + (0.0002708 x (leg length x sitting height)) + (-0.001663 x (age x leg length)) + (0.007216 x (age x sitting height)) + (0.02292 x (mass by stature ratio x 100)).For the OHS assessment, participants were instructed to hold a wooden dowel with extended arms above the crown of their head and, while maintaining the OH position, squat as low as possible. Following three warm-up trials, three further repetitions were performed and recorded using the motion analysis system, HumanTrak (Vald Performance, Brisbane, Qld, Australia). The sum of knee flexion angle for both limbs for the OHS were averaged for the three repetitions and used in the analysis.To measure the CMJ, participants were required to jump with their hands placed upon their hips and instructed to descend to a self-selected countermovement depth before immediately jumping as high as possible. Following three warm-up trials, participants performed three test trials on dual portable force platforms (ForceDecks, Vald Performance, Brisbane, Qld, Australia), with at least 20 seconds between trials. The average of the three jumps were analysed.For acceleration speed, electronic timing gates were used (Brower Timing Systems, Draper, Utah, USA). Following a standardised warm-up comprising submaximal running efforts over a 10-m distance and two practice trials at maximal intensity, each participant completed three trials with at least 60-seconds recovery between trials. Participants began each trial in a The speed-run route was designed in accordance with Strafford et al. [