Protein - Putting it together: A prescription for athletes

Protein for Athletes | Perfect Health Diet

Putting it together: A prescription for athletes

Let’s say our athlete is an 80 kg man. Then maximum muscle gain will be achieved at a protein intake of 1.875*80 = 150 g/day. Toxicity will begin somewhere between 150 to 200 g/day. So the “plateau region” where all the benefits, and none of the toxicity, are achieved is between 150 g/day and some protein intake not much above 150 g/day.
The plateau region is quite narrow! What this tells us is that athletes should consume about 150 g/day protein.

This assumes a high-carb diet, so that no protein is needed for gluconeogenesis. The body utilizes about 600 calories/day of glucose, plus another 100 calories per hour of intense training.

With carb intakes below 600 calories/day, additional dietary protein would be needed, because protein would be consumed nearly 1-for-1 with the missing carbs.

So we can summarize these results as follows:

• On a high-carb diet (>600 calories/day), 600 protein calories/day maximizes muscle gain.
• On a low-carb diet (<600 calories/day), 1200 carb+protein calories/day maximizes muscle gain.

Looking back at Advocatus Avocado’s personal experience, he eats a low-carb diet with 460 carb calories per day. We predict therefore that he would need 740 protein calories a day to maximize his muscle gain (plus up to another 100 calories per hour of training, to replace lost glycogen).

Advocatus says he needs 800 protein calories/day to maximize muscle gain. Close enough for blog work!

At these protein intake levels, Advocatus is probably experiencing mild ammonia toxicity. He might slightly improve his health by eating a few more carbs, and cutting his protein intake a bit.

He might also find that leucine supplementation would reduce his protein needs a bit.
Overall, however, I think his experiences are consistent with our framework for understanding nutritional needs.

Those who are content with maintaining an ordinary person’s muscle mass can get by with relatively low protein intakes of 0.8 g/kg/day or less. But muscle-building athletes need high protein intakes, around 1.9 g/kg/day, to maximize the rate of muscle gain. If they eat low-carb, they may need even more protein. Such high protein intakes are likely to exceed the threshold of toxicity.

References

[1] Brooks, G.A., Fahey, T.D., & Baldwin, K.M. (2005). Exercise physiology: Human bioenergetics and its applications. Boston, MA: McGraw-Hill.
[2] Wilson, J., & Wilson, G.J. (2006). Contemporary issues in protein requirements and consumption for resistance trained athletes. Journal of the International Society of Sports Nutrition, 3(1), 7-27.
[3] Rudman D et al. Maximal rates of excretion and synthesis of urea in normal and cirrhotic subjects. J Clin Invest. 1973 Sep;52(9):2241-9. http://pmid.us/4727456.