Vast research supports the contention that individuals engaged in regular exercise training require more dietary protein than sedentary individuals.
Protein intakes of 1.4 – 2.0 g/kg/day for physically active individuals is not only safe, but may improve the training adaptations to exercise training.
The current recommended level of protein intake (0.8 g/kg/day) is estimated to be sufficient to meet the need of nearly all (97.5%) healthy men and women age 19 years and older. This amount of protein intake may be appropriate for non-exercising individuals, but it is likely not sufficient to offset the oxidation of protein/amino acids during exercise (approximately 1–5% of the total energy cost of exercise) nor is it sufficient to provide substrate for lean tissue accretion or for the repair of exercise induced muscle damage
Relative to endurance exercise, recommended protein intakes range from of 1.0 g/kg to 1.6 g/kg per day [2,4,7,15] depending on the intensity and duration of the endurance exercise, as well as the training status of the individual. For example, an elite endurance athlete requires a greater level of protein intake approaching the higher end the aforementioned range (1.0 to 1.6 g/kg/day). Additionally, as endurance exercise increases in intensity and duration, there is an increased oxidation of branched-chain amino acids, which creates a demand within the body for protein intakes at the upper end of this range. Strength/power exercise is thought to increase protein requirements even more than endurance exercise, particularly during the initial stages of training and/or sharp increases in volume. Recommendations for strength/power exercise typically range from 1.6 to 2.0 g/kg/day [3,11-13,16], although some research suggests that protein requirements may actually decrease during training due to biological adaptations that improve net protein retention