Most research confirms that the body's increased use of protein, as a "fuel" and for repair, increases with aerobic exercise, especially during high intensity and long duration activity. Protein intake higher than the United States Food and Drug Administration's Recommended Dietary Allowance (RDA), with additional energy and resistance training, results in optimal protein status for participants in strength training. Although many active individuals interpret this research to mean that they need to consume extra protein foods or supplements to perform optimally, most people in the United States already consume protein at a level well above the RDA. Physicians should be aware that low energy consuming individuals (e.g., women, those dieting for weight loss, the elderly) may be at risk for low protein intake, and thus protein status, if they are active.