An experiment was conducted in which volume of used oxygen per stride time and the total segmental changes in kinetic energy generated per stride time, DeltaEk s-1, of 11 participants were determined on Day 1 for 7 treadmill running speeds. Gait transition speeds were determined on Day 2. Running metabolism and transition speed were predicted from the Day 1 mechanics of running expressed in Speed x DeltaEk s-1 coordinates. Predictions followed from the relation between 2 generalized quality ratios Qmetab, and Qmech, with numerator DeltaEk s-1. In Qmetab, the denominator was the volume of used oxygen per stride time; in Qmech, the denominator was the absolute regression constant from the linear dependency of DeltaEk s-1 on speed.