Situations that are perceived to be personally important typically evoke intense mood states and emotions; individuals will try to control mood states and emotions, and mood and emotions influence our thoughts and behaviours. Providing the sound knowledge base is a driving factor behind a great deal of the ensuing research and forms the content of many of the chapters of this book. The book covers many aspects of mood in performance settings. Chapters focus on the nature of mood, the validity of mood measures and applied research. Theoretical issues on the nature of mood and a conceptual model of mood-performance relationships in sport is reviewed. Chapters include research on relationships between mood and performance, motivation, coping strategies, personality, eating attitudes, humour, and emotional intelligence. Mood responses to intense exercise, extreme environments, aqua-massage, and interventions to enhance mood are also covered. Each chapter provides recommendations for future research.