Ego depletion is under scrutiny for low replicability, possibly reflecting the limited statistical power available in between-subject designs. In response, we created a within-subject, repeated-measures ego-depletion paradigm that repeatedly alternated depletion and recovery manipulations. Each manipulation was followed by measuring subjective fatigue, mood, and self-control performance. Across 12 studies (N = 754), participants reliably reported having lower energy and mood after depleting manipulations compared to after recovery manipulations. Depletion manipulations did not consistently affect behavioral self-control, although the depletion effect was meta-analytically significant (d = .045). Furthermore, unintended fatigue and practice effects occurred over the course of the paradigm, systematically interfering with the intended depletion effects. We recommend that depletion research takes advantage of within-subject designs across multiple sessions to avoid spillover effects between measurements. (PsycINFO Database Record (c) 2018 APA, all rights reserved)