This study was designed to develop a single-stage submaximal treadmill jogging (TMJ) test to predict VO[subscript 2]max in fit adults. Participants (N = 400; men = 250 and women = 150), ages 18 to 40 years, successfully completed a maximal graded exercise test (GXT) at 1 of 3 laboratories to determine VO[subscript 2]max. The TMJ test was completed during the first 2 stages of the GXT. Following 3 min of walking (Stage 1), participants achieved a steady-state heart rate (HR) while exercising at a comfortable self-selected submaximal jogging speed at level grade (Stage 2). Gender, age, body mass, steady-state HR, and jogging speed (mph) were included as independent variables in the following multiple linear regression model to predict VO[subscript 2]max (R = 0.91, standard error of estimate [SEE] = 2.52 mL [middle dot] kg[superscript -1] [middle dot] min[superscript -1]): VO[subscript 2]max (mL [middle dot] kg[superscript -1] [middle dot] min[superscript -1]) = 58.687 + (7.520 x Gender; 0 = woman and 1 = man) + (4.334 x mph) - (0.211 x kg) - (0.148 x HR) - (0.107 x Age). Based on the predicted residual sum of squares (PRESS) statistics (R[subscript PRESS] = 0.91, SEE[subscript PRESS] = 2.54 mL [middle dot] kg[superscript -1] [middle dot] min[superscript -1]) and small total error (TE; 2.50 mL [middle dot] kg[superscript -1] [middle dot] min[superscript -1]; 5.3% of VO[subscript 2]max) and constant error (CE; -0.008 mL [middle dot] kg[superscript -1] [middle dot] min[superscript -1]) terms, this new prediction equation displays minimal shrinkage. It should also demonstrate similar accuracy when it is applied to other samples that include participants of comparable age, body mass, and aerobic fitness level. This simple TMJ test and its corresponding regression model provides a relatively safe, convenient, and accurate way to predict VO[subscript 2]max in fit adults, ages 18 to 40 years. (Contains 1 figure and 3 tables.)