Some scientists have called for an increase in dietary protein for those who reach a threshold level of exercise. But there are some who question this recommendation. Limitations in the procedures used to justify changing the protein RDA are at issue. N balance has been used to justify an increase in the dietary protein RDA for athletes, but this procedure is limiting even when performed in a well-controlled setting. Experimental short comings are only exacerbated when performed in an exercise field setting. This review concludes that an adaptive metabolic demand model may be needed to accurately study the protein health of the active individual.