Gamification, i.e., the use of game elements in non-game contexts, aims to increase peoples’ motivation and productivity in professional settings. While previous work has shown both positive as well as negative effects of gamification, there have been barely any studies so far that investigate the impact different gamification elements may have on perceived stress. The aim of the experimental study presented in this paper was thus to explore the relationship between (1) leaderboards, a gamification element which exchanges and compares results, (2) heart rate variability (HRV), used as a relatively objective measure for stress, and (3) task performance. We used a coordinative smartphone game, a manipulated web-based leaderboard, and a heart rate monitor (chest strap) to investigate respective effects. A total of n = 34 test subjects participated in the experiment. They were split into two equally sized groups so as to measure the effect of the manipulated leaderboard positions. Results show no significant relationship between the measured HRV and leaderboard positions. Neither did we find a significant link between the measured HRV and subjects’ task performance. We may thus argue that our experiment did not yield sufficient evidence to support the assumption that leaderboard positions increase perceived stress and that such may negatively influence task performance.