This review examines the physiological and psychological dimensions of overtraining and burnout in individual sports, and their implications for athletic performance and well-being. The greater responsibility, stress and isolation that individual sports place on athletes increases their vulnerability to maladaptive training responses. Overtraining is discussed as an imbalance between training load and recovery, and is categorised as either functional or non-functional, with subtypes linked to autonomic nervous system responses. Its aetiology involves physiological, psychological, and neurological mechanisms, and diagnosis requires monitoring of performance, mood, biochemical markers, and recovery status. By contrast, burnout is conceptualised as a motivationrelated syndrome characterised by emotional exhaustion, depersonalisation and a reduced sense of achievement, which is often influenced by environmental and psychosocial stressors. The review highlights the close relationship between chronic overtraining and burnout, noting that inadequate recovery and prolonged stress can cause athletes to withdraw from sport. Effective prevention requires coordinated monitoring, appropriate training and rest, balanced recovery strategies, and psychosocial support.