We examined the relationship between mindfulness tendencies and state and trait anxiety, perceived pain, exertion, performance satisfaction, attention, self-efficacy, and negative thinking in cross-country running. Thirteen collegiate athletes performed either a 3 or 5 km race, depending on which was their main competitive event. Before the race, they completed surveys on mindfulness and anxiety. After the race, they reported their perceived levels of exertion, pain, attention, self-efficacy, and performance. Descriptive and inferential data analysis revealed that (a) runners higher in mindfulness reported higher levels and more instructional self-talk statements of pain than those low in mindfulness, and (b) moderate-to-strong correlations among rates of perceived exertion and pain, attentional focus, and somatic anxiety. These results suggest that unpleasant affective states are inherent to running, and thus practitioners should help athletes to develop idiosyncratic coping strategies to enhance performance and well-being.