Souhail, H, Castagna, C, Mohamed, Hy, Younes, H, and Chamari, K. Direct validity of the Yo-Yo intermittent recovery test in young team handball players. J Strength Cond Res 24(2): 465-470, 2010-The aim of this study was to examine the possible association between Yo-Yo intermittent recovery test level 1 performance (distance covered, Yo-Yo IR1) and match activities (direct validity) in young male team handball players. Eighteen young male players (age 14.3 ± 0.5 years, body mass 64 ± 28.7 kg, height 174 ± 6 cm, body fat 11.2 ± 3.9%) took part in this study. Players' match activities were videotaped during an experimental tournament (6 games/player) and analyzed using a computerized system. Games and Yo-Yo IR1 heart rates (HRs) (short-range telemetry, HR) and blood lactate concentrations ([la]b) were assessed throughout and at selected times of the games, respectively. Peak Yo-Yo IR1 HR was assumed as representative of individual maximal HR (HRmax). Mean and peak game HRs were 174 ± 3 and 198 ± 2 b·min−1, which corresponded to 87 and 99% of HRmax, respectively. Yo-Yo IR1 performance (1,831 ± 373 m) was significantly related (r = 0.88, p < 0.01) to total game distance (1,921 ± 325 m). Post-game (9.2 ± 2.3 mmol·L−1) and Yo-Yo IR1 (8.8 ± 1.6 mmol·L−1) [la]b were significantly related (r = 0.51, p < 0.05). These findings demonstrated the direct validity of Yo-Yo IR1. Consequently, Yo-Yo IR1 test may be considered as a team handball test relevant for the assessment of intermittent high-intensity endurance in young male team handball players.