Signs of nutritional deficiency related to physical performance can include decreased energy levels, muscle weakness, and impaired endurance. Common symptoms may manifest as fatigue, slow recovery from exercise, and increased susceptibility to illness. Specific deficiencies, such as in iron or vitamins like B12, can severely impact athletic performance by reducing oxygen transport and energy production. Athletes may also experience cramping or reduced muscle function due to inadequate electrolyte intake. Recognizing these signs early is essential for addressing deficiencies and maintaining optimal physical capabilities.