Key signs of a healthy body include consistent energy levels, good sleep quality, and balanced body weight. Additionally, an absence of chronic pain or discomfort and normal functioning of vital systems, such as cardiovascular and digestive systems, are indicators of health. Skin appearance, hair and nail condition can also reflect overall health. Regular physical activity, along with a nutritious diet, contributes to these signs, promoting not only physical fitness but also enhanced well-being and resilience against illnesses.