Locomotor performance and activity energetics were analyzed in 19 individual helodermatid lizards ranging in mass from 24.5-1220 g. We measured maximum sprint speeds, endurance on a treadmill, cost of transport, and aerobic capacity (rO2max) at a mean body temperature of 30.8 C. The maximum sprint speed for both Heloderma species averaged 1.7 km/h, which is among the lowest recorded for lizards...
