The 3 Minute Step Test is a validated field test to evaluate the functional exercise capacity in children aged 6 to 12.

BACKGROUND: Field tests are useful to assess the functional exercise capacity. The 6minute walking test (6MWT) is the most common field test even if alternatives are needed. The main aim of the study was to verify if the 3minute step test (3MST) is a valid tool to measure the functional exercise capacity and can surrogate the 6MWT in healthy children from 6- to 12-years-old. METHODS: This randomized cross-over trial recruited 30 healthy children from 6 to 12 years. One 6MWT and two 3MST (3MST1 and 3MST2) were performed randomly on 3 consecutive days. The variables were the distance (6MWT), the number of steps (3MST) and the cardiorespiratory parameters. RESULTS: The distance walked during 6MWT was very strongly correlated to the number of steps during the 3MST (3MST1: rho=0.833; P<0.001 and 3MST2: rho=0.868; P<0.001). Heart rate (HR) was lower than the theoretical maximal HR at the end of both tests. The change in HR and perceived fatigue were significantly higher after the 3MST. A learning effect was observed in the 3MST (+8 steps; P<0.001). CONCLUSIONS: The 3MST is validated and can be a surrogate for the 6MWT in healthy children population between 6 and 12 years old. A training test is required in these children.