The discriminative, criterion, and longitudinal validity of small-sided games to assess physical fitness in female basketball players.

The validity of small-sided games (SSG) for assessing physical fitness was evaluated in 21 female basketball players from senior ( = 8), under-18 years ( = 6), and under-16 years ( = 7) age categories. Players underwent fitness testing (countermovement jump [CMJ], agility T-test, repeated-sprint ability (RSA) test, and Yo-Yo Intermittent Recovery Test [YYIRT1]) and 3vs3-SSG before and after a 6-week preseason. Player demands were monitored during SSG using local positioning system and heart rate technology. Regarding discriminative validity, senior players produced better CMJ, agility T-test, and YYIRT1 performance (  < 0.05, effect size [ES] = 1.72-2.25), and more distance and PlayerLoad (  < 0.05, ES = 1.53-2.47) during SSG than under-18 players following the preseason. For criterion validity, total distance and distance completing high-intensity decelerations during SSG were significantly (  < 0.05) correlated with CMJ ( = 0.44-0.66), YYIRT1 ( = 0.43-0.63), agility T-test (total distance only, =-0.51), and RSA test performance (=-0.49 to -0.52) among all players combined following the preseason. Regarding longitudinal validity, significantly better agility T-test and YYIRT1 performance ( ≤ 0.001, ES = 0.88-0.93) alongside lower heart rate during SSG ( = 0.001, ES = 0.88) were evident for all players combined following the preseason. These results partially support the validity of 3vs3-SSG to assess physical fitness in female basketball players.