AbstractThis study compared maximum oxygen consumption (VO2max) on a 20-meter multistage shuttle run test (20-Srt) with a cardiopulmonary exercise test (CPET) to determine a VO2max prediction equation for a 20-Srt in children aged 6–10 years. Eighty healthy children performed the CPET on a treadmill, while the 20-Srt took place on a sports court. Heart rate (HR) was measured and the expired gases were continuously measured breath-by-breath using a portable gas analyzer. The VO2max was lower (p<0.05) in CPET than 20-Srt for all, female, and male participants, respectively (46.3±7.9 vs. 48.7±4.6; 42.7±7.8 vs. 46.7±4.8; 49.3±6.8 vs. 50.4±3.9, mL·kg-1·min-1). The standard error estimates were between 3.0 and 3.6 and considered as not clinically relevant if less than 5 mL·kg-1·min-1. The intraclass correlation coefficient between the VO2 in CPET and in 20-Srt was 0.74 (CI95% 0.55–0.84) and considered moderately reliable. The linear multiple regression excluded sex, body mass index and fat-free mass and retained the maximum speed and age in the predictive equation. The 20-Srt estimates the VO2max with moderate reliability and the predictive equation was VO2maxpred=4.302+(maximum speed*5.613)–(age*1.523) for children aged 6–10 years.