Protein requirements endurance exercise

The majority of the energy for endurance exercise is derived from the oxidation of lipid and CHO. As mentioned above, skeletal muscle has the metabolic capacity to oxidize certain amino adds for energy. While it may se n counterproductive to oxidize proteins during exerdse since they serve eitha- a structural or functional role, amino add oxidation may also be required for exchange reactions in the tricarboxylic acid cycle, and this may increase their net utilization. ... 

With moderate-intensity endurance exercise ( 50% VOjpea ), there does not appear to be an increase in protein requirements.At these modest exercise intensities, protein utilization is enhanced and energy deficits are better tolerated. 

In contrast to endurance exercise, resistance exercise results in muscle hypertrophy rather than an increase in amino acid oxidation and mitochondrial biogenesis. If, for example, there are no changes in efficiency of amino acid retention, there must, at some point, be a protein intake in excess of basal requirements to provide the amino acids required for anabolism. The extent of this increased need is again a fimction of the basal state of training, the duration, and the intensity of the training program. 

Athletes associate performance with diet. Meat became a staple of ancient Greek and Roman athletes as they attempted to achieve the strength and endurance of carnivorous members of the animal kingdom. As knowledge of nutrition and muscle physiology increased, athletes became convinced that to increase muscle mass and strength required increased dietary protein. However, nutrition textbooks (1,2) and the Recommended Dietary Allowances (RDA s) established by the National Academy of Sciences (.3) state that there is little or no need for extra protein for exercise. 

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