The aim of the present study was to characterize aerobic responses to HIIE and CE in prepubertal children. Twenty-five8 to 11-year-oldchildren took part to a preliminary visit to determine peakVO2and Maximal Aerobic Velocity (MAV). During the 5-followingexperimental visits, theparticipantscompleted2 CE and 3 HIIEsessionsin a randomized order. The HIIE consisted ofshort intermittent 10 and20-s running bouts from 100 to 130% of MAV, interspersed with recovery periods of equal duration (S-HIIE1 and S-HIIE2 respectively)and5-s sprinting and jumping at maximal intensity with 15-s recovery periods (S-HIIE3). Continuous submaximal exercises consistedoftwo 10-min running periods at 80% and 85% of MAVwith a 5-min recovery period.CEprotocols elicitedhigher average VO2and exercise time spent above 95%of peakVO2thanHIIE protocols. S-HIIE 1 and S-HIIE 2 elicited similar average VO2responseand higherthan S-HIIE 3. Our study has shown that CE activated the aerobic system to a greater extent than S-HIIE in prepubertal children, as reflected byexercise time above 95% of peakVO2. However, isotime S-HIIE protocols of either 10 or 20-s exercise bouts at an intensity aboveMAV result tosimilar exercisetimes at high oxygen consumption rates (above 95% VO2peak).