Mindfulness training—learning to pay attention to the present moment nonjudgmentally—was introduced into American sports in the 1980s. Mindfulness in this chapter is an umbrella term which includes diverse practices that can be employed to train for attention and acceptance, including focused attention, observing, and questioning one’s thoughts with cognitive practices, open monitoring, body scans, walking and moving practices, and integrating mindfulness into daily activities. There are also mindfulness techniques for cultivating gratitude, compassion, equanimity, and kindness. Neurophysiological studies reveal that mindfulness may build the brain’s areas of focus and attention, stretch mental perceptions of limitations, assist with emotional regulation and pain management, encourage proper breathing techniques, lower stress hormone levels, engage the parasympathetic nervous system, and reduce cardiovascular risks—all critical to athletes and those rehabilitating. The psychosocial and physical demands during intense exercise can also initiate a stress response activating the hypothalamus-pituitary-adrenal (HPA) axis, resulting in the release of inflammatory cytokines. Research has shown that mindfulness can reduce inflammatory cytokine concentrations and other stress markers, and even improve sports performance. In this chapter, we summarize the compelling evidence of mind body benefits for rebalancing the athlete for performance, as well as the limitations of the existing research.