In this paper we examine the influence of auditory augmentation on the act of jumping on an elastic trampoline. To do so we have developed a system that interactively augments the sound of a trampoline when a user is jumping on it. The sound design is inspired by iconic jumping sounds from games and the synthesis engine allows for parametric control of the sound features. The sensing technology is based on a combination of motion tracking with depth camera and audio-based contact sensing between the feet and the trampoline. The system lets the user interactively control the sound by jumping. We conducted a study to evaluate the effect of manipulating the auditory feedback during the jumping exercises. Results show that our interactive sonification positively affects the user experience during the exercise and stimulates changes in the user's behavior toward increased performance. Our system and study provide evidence that interactive sonification can act as a motivational tool in training and add an extra fun-factor to body-controlled games.