Ego depletion does not negatively impact novice sprinters' start performance during a timed 20m all-out sprint

Temporary reductions in self-control due to previous cognitive effort, also known as 'ego depletion', have been shown to negatively impact performance in subsequent tasks requiring self-control. Various theoretical accounts suggest that high levels of task motivation may prevent negative behavioural effects of ego depletion. Against this background, the current study performed a conceptual replication of a previous study examining the effects of ego depletion on sprint start performance (i.e., Englert et al., 2015) and implemented additional monetary incentives to manipulate task motivation. Using a pretest-intervention-posttest design, ninety-six novice sprinters performed a sprinting task that required them to complete a series of 20-m sprints. In between pretest and posttest, participants performed a letter writing task either under high cognitive demand (depletion group) or low cognitive demand (non-depletion control group). Subsequently, and prior to starting the posttest, participants were presented either with a monetary incentive or no incentive. Manipulation checks confirmed that the letter writing task successfully manipulated perceived regulatory demand and that task motivation at the posttest was higher for participants who were offered a monetary incentive. The number of false starts decreased significantly with ego depletion, while sprint start reaction times and sprint finish times remained unaffected. Regardless of ego depletion, sprint finish times significantly improved with monetary incentives. These results suggest that brief engagement in a demanding cognitive task is unlikely to impair novice sprinters' ability to self-regulate during the start of a subsequent, maximal sprinting effort for which they are highly motivated.