Introduction Small-sided games (SSGs) are suggested as an excellent training tool to improve physiological capacities and simulate the high physiological demands of full-sized matches (Abrantes et al., 2012). However, it is unclear if the physiological response to playing SSGs differs between age categories leading to differences in physiological adaptations. Therefore, the aim of this study is to determine the physiological response in standardized SSGs of elite-standard youth soccer players of different age categories. Methods Thirty-nine elite-standard male youth soccer players were assigned to four teams (under-16, under-17, under-18 and under-19) and played six SSGs. Each SSG’s duration was 6 minutes, with a 1.5-minute rest in between. Pitch size was 40x30m. Positional data (LPM) and heart rate data (Polar) were collected during the SSGs to calculate (mean ± sd) covered distance (m), number of sprints and heart rate (bpm) per team. Team differences were statistically evaluated (MANOVA). Results Under-19 covered less distance and performed a lower number of sprints than under-18 and under-17 during the small-sided games (respectively 685.6 ± 51.8m, 770.5 ± 31.2m and 760.9 ± 20.2m; 11.1 ± 1.1, 14.1 ± 2.0 and 14.4 ± 1,4; p0.05). Discussion Results indicate an age-related difference in the physiological response during SSGs. Although similar duration and pitch sizes were used, the physiological demands were lower for the under-19 team. Comparable results were observed in regular soccer practices of elite Portuguese soccer players (Abade et al., 2013). This illustrates the need for age-specific designs for SSGs to evoke adequate physiological responses in elite-standard youth soccer players. References Abade E., Gonçalves B., Leite N. & Sampaio J. (in press). Int J Sports Physiol Perform Abrantes C., Nunes M., Maças V., Leite N. & Sampaio J. (2012). J Strength Cond Res, 26, 976-981