University Medicine Greifswald 1 article published in JoVE Behavior Visualization of Intensity Levels to Reduce the Gap Between Self-Reported and Directly Measured Physical Activity Lisa Voigt1,4, Antje Ullrich1,4, Ulrike Siewert-Markus1,2,4, Marcus Dörr3,4, Ulrich John1,4, Sabina Ulbricht1,4 1Institute of Social Medicine and Prevention, University Medicine Greifswald, 2Institute for Medical Psychology, University Medicine Greifswald, 3Department of Internal Medicine B, University Medicine Greifswald, 4partner site Greifswald, DZHK (German Centre for Cardiovascular Research) This protocol describes a randomized controlled trial as a method to test the effect of a video demonstration on the intra-individual difference between self-reported and accelerometer-based moderate-to-vigorous physical activity.