Challenge and threat reflect two distinct psychophysiological approaches to motivated performance situations. Challenge is related to superior performance in a range of tasks compared to threat, thus methods to promote challenge are valuable. In this paper we manipulate challenge and threat cardiovascular reactivity using only resource appraisals, without altering perceived task demands between challenge and threat conditions. Study 1 used a competitive throwing task and Study 2 used a physically demanding climbing task. In both studies challenge task instructions led to challenge cardiovascular reactivity and threat task instructions led to threat cardiovascular reactivity. In study 1, participants who received challenge instructions performed better than participants who received threat instructions. In study 2, attendance at the climbing task did not differ across groups. The findings have implications for stress management in terms of focusing on manipulating appraisals of upcoming tasks by promoting self-efficacy and perceived control, and focusing on approach goals. Future research could more reliably assess the influence of similar task instructions on performance.