Final answer:
Athletes engaged in daily exercise struggle to maintain nitrogen balance when consuming less than 1.2 to 2.0 grams of protein per kilogram of body weight. Nitrogen balance is crucial for muscle maintenance and growth, which necessitates an adequate protein intake. The biological value of protein also affects the quantity needed to achieve this balance.
Step-by-step explanation:
Research has indicated that athletes who are engaged in daily exercise may have difficulty maintaining nitrogen balance when their dietary protein intake falls below 1.2 to 2.0 grams per kilogram of body weight. Nitrogen balance is a state where the intake of nitrogen from proteins matches the excretion of nitrogen in waste products; an imbalance can result in negative effects such as muscle loss.
Therefore, to support metabolic functions and muscle maintenance, growth, and repair, it is recommended that athletes consume an adequate amount of high-quality protein. Furthermore, athletes should be mindful of the biological value of protein, ensuring they're consuming enough to maintain a positive nitrogen balance, particularly during periods of intense training or when reducing energy intake.