Tracking macronutrients in a fitness regimen is significant as it supports optimal body composition and performance. Macronutrients, including carbohydrates, proteins, and fats, play different roles in energy production, muscle repair, and overall health. By monitoring intake, individuals can ensure they meet their specific fitness goals, such as weight loss or muscle gain. Additionally, tracking macronutrients helps to maintain a balanced diet, prevent nutrient deficiencies, and promote long-term adherence to healthy eating habits, ultimately enhancing physical performance and recovery.