This experiment manipulated elite endurance cyclists’ implicit beliefs about the nature of decision-making ability and explored subsequent change in performance on a decision-making task under submaximal physiological load. In total, 54 elite-level endurance cyclists (10 women and 44 men) were manipulated to endorse a limited (susceptible to depletion) or nonlimited (unsusceptible to depletion) implicit belief about decision-making ability. Results showed that after the manipulation cyclists assigned to the limited resource condition had higher levels of limited beliefs and lower levels of nonlimited beliefs than those assigned to the nonlimited resource condition. Those in the limited resource condition also showed a decrease in decision-making performance, whereas those in the nonlimited resource condition showed an increase in decision-making performance. Findings suggest that implicit beliefs about decision-making ability can be manipulated in an elite sport sample and that such manipulation can alter performance on a decision-making task under submaximal physiological load.