px-r-F5cPQX9ZxUrwgORsMGDGwU Kuhnesiology: Article 2 on Justflysports.com

Monday, February 20, 2012

Article 2 on Justflysports.com

Hey everyone.  My 2nd nutrition article is up on justflysports.com

check it out!


Nutrition for the Power Athlete: Part 2. Protein
by Kevin Kuhn, MS, CSCS

If you are reading this, hopefully you have taken the time to figure out your daily caloric needs based on last weeks article.  Now that we have that number...the specific breakdown of the 3 calorie containing macronutrients (Protein, Carbohydrate, Fat) can be done.

The traditional breakdown for most Power Athletes has been 55-60% of calories from carbohydrates, 12-15% of calories from protein, and 30% of calories from fat (with less than 10% of that coming from saturated fats).

These ratios are specific to the Power Athlete because, according to the International Society of Sports Nutrition, they will:
"...provide enough protein to support the normal regenerative processes and promote muscle growth and strength gains"
"...stock glycogen stores for athletic performance"
"...maintain a positive energy balance"
"...replenish intramuscular triglyceride stores"
and "support anabolic hormone production"

Hopefully it makes sense that these 3 macronutrients are extremely important to athletic performance, since diet has so much more to do with athletics than providing fuel. The name "Power Athlete" has been claimed by many different sports/athletic activities on the metabolic demands spectrum.  By this I mean that traditional powerlifters, those who compete in the "Olympic" lifts, football athletes, track and field sprinters, and many other athletes have been called "Power Athletes."  True measures of "power" that last fewer than 30 seconds require a different diet than activities that last longer than 30 seconds. This is because the high intensity activity up to 30 seconds really only depends on high energy phosphates (existing ATP and phosphocreatine) with little reliance on stored glycogen, whereas activity lasting longer than 30 seconds, especially those with intermittent rest/activity periods, rely more and more on stored glycogen as physical activity time increases. This means that a diet to promote performance for true power activities will require a lesser percentage of carbohydrates and an increased percentage of protein and fat to maintain caloric balance.

That being said...this week will cover the basics of Protein.

Protein, which provides 4 calories per gram, is composed of nitrogen containing structures called amino acids. There exist 20 different amino acids, of which 11 are non-essential, meaning they do not have to be obtained in the diet since the body can make them from other compounds, and 9 which are essential, meaning they must be
obtained through the diet. It is these essential amino acids that are necessary for various biochemical processes within the body, but specifically for tissue growth and repair.  Bottom line:  Without the appropriate intake of dietary protein, repairing damaged tissue and maximizing strength and power along with the adaptations to exercise and training cannot occur.

So how much is enough?
Though it is recommended that 12-15% of total calories come from protein, a more specific calculation to promote maximal recovery and adaptation to training is to get 1.5 to 2.0 grams of protein per kilogram of body weight daily. For example:  I am 160 lbs.  160 / 2.2 = 72.7 kilograms.  72.7 x 1.5 to 2.0 = 109 to 145 grams of protein per day. This calculation still fits the percentage of my total calories since 145 grams of protein comes to 580 (145 x 4 kcal/gram) calories, which makes up about 14% of my total caloric needs (4077 calories/day).

109 grams to 145 grams of protein per day?  Really?  Yes.

The 1.5 to 2.0 grams of protein per kilogram of body weight may seem high when compared to the previous recommendation of 0.8 to 1.0 grams of protein per kilogram of body weight, or the measly 50 grams (or "ounce" equivalents) per day still recommended by the CDC, USDA, and some, but not all, Registered Dietitians.

Timeout. I don't want this to be a rant against governmental agencies or dietitians. Please understand that I am not trying to attack them. I just believe that the research backing a high protein diet must not be ignored. A specific study published in the Journal of Applied Physiology and conducted by Tarnopolskyet. al. looking at the protein requirements of power athletes showed that in order to maintain a positive nitrogen balance (ingesting enough protein for tissue repair and growth), these subjects had to ingest 1.4 to 2.4 grams of protein per kilogram of body weight. So 50 grams...just doesn't cut it if you want to any athletic development and improvement. Also, the  "hazards" of a high protein diet have been very exaggerated. Both the National Academy of Sciences and the Harvard School of Public Health conclude in their reviews of literature on high protein ingestion that this type of diet does not increase risk for coronary heart disease. Along with that, no study has ever shown or reported either kidney or liver damage in individuals who begin a high protein diet with properly functioning kidneys and liver. High protein intake was once thought to weaken bones since calcium is needed to buffer acidity associated with protein metabolism; however, we now understand that phosphate in protein rich foods negates the need to pull calcium from bones, and there is thus a high correlation between bone strength and protein intake.

I do want to dedicate an entire paragraph to the next issue: Hydration. Since protein contains nitrogen, and this dietary nitrogen is processed via the urea cycle and then removed via the urinary system, it is very important to monitor hydration levels when on a high protein diet.  This is very important since athletic performance can significantly decrease with as little as 3% loss of total body water.  Be sure to drink plenty of water throughout the day to help maintain both a proper hydration status as well as healthy urinary system.

Now that the "cons" have been addressed, the next most important thing to consider is nutrient timing.  Taking 145 grams of protein in 1 sitting would not be a very wise thing for me to do since the body cannot adequately utilize that much at a time. I would be much better off to spread my protein intake throughout the day. There have been various studies conducted to figure out just how much protein the body can metabolize and utilize at a time, but due to so manyindividual/biological differences in people, there is no set number. Some say 10 grams or less can be fully utilized per hour.  Others say the body is so good at adapting to what is ingested, that double or triple that can be digested and utilized per hour.  My suggestion is to spread it out in approximately 20-30 gram chunks throughout the day, beginning with breakfast as soon as you can upon waking, and right before you go to bed (to maximize recovery).  Probably the most important aspect of nutrient timing deals with the time around your training session. Research is quite clear that ingestion of 20-30 grams immediately before, immediately after, or both before and after physical activity results in greater muscle protein synthesis as well as strength and power gains. A specific study conducted by Anderson et. al. published in the journal Metabolism compared young men who supplemented 25 grams of protein before and after strength training to a group who supplemented 25 grams of carbohydrate before and after strength training. This 14 week study showed that the protein group had 18-26% greater gains in muscle mass in comparison to the carbohydrate group.

So the total amount of protein is very important...but even more important is when you get it.  Whether its right before or right after...just make sure you get it!

Tarnopolsky, M.A., Atkinson, S.A., MacDougall, J.D., Chelsey, A.,Phillips, S., & Schwarcs, H.P. (1992).  Evaluation of protein requirements for trained strength athletes.
Journal of Applied Physiology. 73:  1986-1995.

Anderson, L.L., Tufekovic, G., Zebis, M.K., et. al.  (2005).  The effect of resistance training combined with timed ingestion of protein on muscle fiber size and muscle strength.  Metabolism.  54(2): 151-156.

Ziegenfuss, T.N. & Landis, J.  (2008).  Protein.  In J. Antonio, D. Kalman, J.R. Stout, M. Greenwood, D.S. Willoughby, and G.G. Haff (Eds.), Essentials of Sports Nutrition and Supplements (pp. 349-370). Totowa, New Jersey:  Humana Press

Stoppani, J., Scheett, T.P., & McGuigan M.R.  (2008).  Nutritional Needs of the Strength/Power Athletes.  In J. Antonio, D. Kalman, J.R. Stout, M. Greenwood, D.S. Willoughby, and G.G. Haff (Eds.), Essentials of Sports Nutrition and Supplements (pp. 349-370).  Totowa, New Jersey:  Humana Press


No comments:

Post a Comment