px-r-F5cPQX9ZxUrwgORsMGDGwU Kuhnesiology: March 2012

Thursday, March 15, 2012

Article # 4 on Justflysports.com

On a low-fat diet?  Might want to read this...and reconsider.


Nutrition for the Power Athlete:  Part 4.  Fat

To conclude the explanation of the macronutrients, we must address fat.  Generally speaking, Power Athletes and the general public should have similar fat intake percentages, which comes to about 30% of total caloric intake. This is because fat, but not just any kind of fat, is very necessary for promoting optimal health. When you break it down...if you aren't healthy, how can you train or compete?

The idea that fat = bad is still very prominent in today's society. This notion is pretty unfortunate since fat (fatty acids) plays such an important role in so, many aspects of human physiology, like providing energy, aiding in the transport of the "fat-soluble" vitamins A, D, E, and K, and promoting anabolic hormone production to name just a few. So how much do you need?

The general consensus is that about 30% of your total caloric intake should come from fat, with 10% or fewer of total caloric intake coming from saturated
fats (keeping as far away as possible from trans fats). The very interesting and important thing to understand is that 1 gram of fat contains 9 calories. That's more than double the calories per gram of protein and carbohydrate. The International Society of Sports Nutrition recommends 10-15% of your total caloric intake come from monounsaturated fatty acids, and 10-15% of total caloric intake come from polyunsaturated fatty acids, with some saturated fat as well. This recommendation is due to the overwhelming evidence from research that is showing a higher fat diet helps to maintain circulating concentrations of anabolic hormones such as testosterone.  There exists much evidence (The Malmo Diet and Cancer Study) that high fat diets, even ones with greater than 10% saturated fat, are not detrimental to health and do not increase mortality.

What's the difference between saturated and unsaturated fatty acids? Glad you asked. It all comes down to molecular bonds and the number of hydrogen atoms that the fat molecule contains. Saturated fat has no carbon-to-carbon double bonds and is "maxed-out" by hydrogen bonds. Because of their molecular nature, they have a higher predisposition to being stored as opposed to used as fuel in comparison to unsaturated fatty acids. In general, saturated fatty acids are solid at room temperature while unsaturated fatty acids are typically liquid (oils) at room temperature.

Saturated fats are mostly from animal sources as well as oils that have been hydrogenated (like margarine), while unsaturated fats are mostly from plant sources. There are two kinds of unsaturated fatty acids:  Monounsaturated fatty acids contain one carbon-to-carbon double bond, and Polyunsaturated fatty acids that contain two or more carbon-to-carbon double bonds. In a similar fashion to specific amino acids characterized as "essential," some Polyunsaturated fatty acids must be obtained from the diet from either plant or animal sources since they cannot be synthesized. Due to our inability to create specific carbon-to-carbon double bonds at specific positions on fatty acid molecules, we must get the unsaturated fatty acids Omega-3 (linolenic acid) and Omega-6 (linoleic acid) from our diet. Though we need both Omega-3 and Omega-6 fatty acids, the specific ratio of these is very important since Omega-6 fatty acids are known to be "proinflammitory" and can therefore play a role in negatively affecting recovery and health if too much is present in the diet. This is an issue since the typical "western" diet has a ratio of about 20:1 of Omega-6 to Omega-3

The Institute of Medicine suggest a 7:1 ratio of these fatty acids. Research just published in the journal Prostaglandins and Other Lipid Mediators, and conducted by Weylandt, et. al.  has shown that Omega-3, on the other hand, reduces inflammation via the production of lipid mediators protectin and resolvin.  Buckley and Howe explain in their review of Omega-3 fatty acids that the role of these lipids may even be beneficial in preventing obesity. The review also states that Omega-3 fatty acids do more than help prevent obesity: "...including suppression of appetite, improvements in circulation which might facilitate
nutrient delivery to skeletal muscle and changes in gene expression which shift metabolism toward increased accretion of lean tissue, enhanced fat oxidation
and energy expenditure and reduced fat deposition."

Wait a minute. Eating Omega-3 fatty acids does what?

-Improves circulation and nutrient delivery
-Shifts metabolism toward lean tissue growth
-Increases the amount of stored fat that is used as energy

Do those sound like beneficial things when it comes to training? Yeah. Those are good.

So what are some good sources of these mono- and polyunsaturated fatty acids?

Monounsaturated:  Olive oil, canola oil, and peanut oil, as well as avocados and most nuts.

Polyunsaturated:  Corn oil, flower oils, sesame oil, soy oil, as well as most nuts and seeds.

What about good sources of Omega-3 fatty acids?

Walnuts and most cold water fish, such as herring, tuna, sardines, mackerel, and salmon. Also...it is pretty easy to find fish oil supplements.

And...since Power Athletes can eat some saturated fat, good sources include: beef and poultry, as well as dairy products. For non-animal source saturated fat, sources include: coconut oil, palm oil, and kernel oil.

AVOID trans fats, which have been shown to promote obesity and other inflammatory diseases, such as heart disease, certain cancers, and diabetes. Trans fats, which are usually plant oils that have been processed to extend shelf life or "hydrogenated" to obtain a specific "solid" characteristic have also been shown to: increase "bad" LDL cholesterol
decrease "good" HDL cholesterol
increase C-reactive protein (a marker of muscle damage and breakdown) 

To avoid these trans fats, check the ingredients label.  If it says "trans fat," "hydrogenated," or "partially-hydrogenated," it should be limited or avoided.

(Note: Just because a label says 0g of trans-fat, this doesn't mean it doesn't have any trans-fat. Food companies can put 0g of trans-fat on their label if there is less than .5g in a serving, so check the ingredients list for the "hydrogenated" or "partially hydrogenated" key words!)

If you can consume the good fats and limit the bad ones, it will really help you as an athlete!  So don't be afraid of fat.  It does much more than insulate and keep you warm.


Buckley, J.D. & Howe, P.R.  (2010).  Long-chain Omega-3 Polyunsaturated Fatty Acids may be Beneficial for Reducing Obesity - a Review. Nutrients.  2(12):  1212-1230.

Hofheins, J.  (2008).  An Overview of Macronutrients.  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

Leosdottir, M., Nilsson, P.M., Nilsson, J.A., Mansson, H., & Berglund, G.  (2005). Dietary Fat Intake and Early Mortality Patterns - Data from the Malmo Diet and Cancer Study. Journal of International Medicine.  258:  153-165. 

Lowery, L.  (2008).  Fat.  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

Weylandt, K.H., Chiu, C.Y., Gomolka, B., Waechter, S.F., & Wiedenmann, B.  (2012). Omega-3 Fatty Acids and their Lipid Mediators:  Towards an Understanding of Resolvin and Protectin Formation.  Prostaglandins and Other Lipid Mediators.  (Epub ahead of print).  

Tuesday, March 6, 2012

3rd Article on Justflysports.com

Check out the third article in the nutrition series on Justflysports.com


Nutrition for the Power Athlete: Part 3. Carbohydrates
By Kevin Kuhn

In the second article in this nutrition series, I explained that approximately 55-60% of the "traditional" Power Athlete's total calories will come from carbohydrates. Though this number will vary based on individual differences as well as sport and activity metabolic demands, the role of carbohydrate for fuel as well as its influence on specific metabolic hormones before, during, and after exercise is of vital athletic importance.

Consuming 5-6grams of carbohydrate per kilogram of body weight is an easy way to calculate that 55-60% of total calories, for most athletes.

Once again we have arrived at a number. And once again I will ask the rhetorical question:  Is this important?

Well, lets say the specific sport/activity you participate in lasts longer than 30 seconds at a time.  In this case, carbohydrate serves as high-intensity fuel. So yes...it is of vital importance to have enough fuel to maintain high intensity activity. No fuel = no performance. But what if your sport/activity is one that last less than 30 seconds. Well, carbohydrate is not necessarily the main fuel source; however, it does still play a significant role. What is that role, you ask?

Well, even if your sport/activity does not last more than 30 seconds...your training does. Training for almost every sport is at least somewhat intermittent, and high intensity intermittent exercise/training depends heavily on carbohydrate for fuel. And thats just the training for your specific event. What about your supplemental training? By that, I am referring to resistance training. It has been very well documented that resistance training and other forms of conditioning depend very highly on adequate carbohydrate ingestion.

Lets just say, for arguments sake, that the sport/activity you train for requires no carbohydrate for fuel...and that your training is not very dependent on carbohydrate for fuel.  Even in this case...to maximize the adaptations to training as well as to promote recovery between training sessions, carbohydrates are still needed.     

Before I discuss how the specific timing of carbohydrates can play a role in training adaptation, we must first understand the glycemic index. The glycemic index is just a simple way of ranking carbohydrate food according to the blood-glucose (blood sugar) response after they have been ingested. Carbs with a high glycemic index (like white bread, sports drinks, and candy) elicit a high blood-glucose response while carbs with a low glycemic index (like oatmeal and legumes) cause less of a dramatic spike in blood-glucose.

It is here...that things can get a little tricky. Carbohydrates in general, but "simple" carbs (high glycemic index) specifically have a very bad reputation. There is nothing inherently wrong with carbohydrates. The issue really comes down to when they are ingested...how much are ingested...and whether or not you sit on the couch all day. This next part may be a bit of an aside...but I feel it is necessary to say.

If you are not participating in high intensity training of some sort...you do not need very many carbohydrates...especially simple carbohydrates. This article is not to discuss insulin sensitivity, so I won't go any further into that. Just know that the body stores carbohydrate in the form of fat very easily in the absence of exercise. Exhibit A: America. 

So what should you eat?  High glycemic index or low glycemic index carbs?

The answer is yes. You should eat both. The specific time you eat either is very important.

The specific issue of nutrient timing with regard to carbohydrate has much to do with insulin. If you've spent any time in a gym, you have probably overheard someone (probably a meathead doing bicep curls in the squat rack, no doubt) say "insulin is the most anabolic hormone." And that is actually true.

Carbohydrate ingestion plays a very big role in muscle/tissue growth and repair.  

This is because when you eat/drink carbohydrates, the pancreas releases insulin. The specific role of insulin is to:  "...lower blood glucose level by enhancing cellular uptake, enhance the storage of glycogen, enhance fat storage, enhance cellular uptake of amino acids, increase the synthesis of proteins, and suppress the catabolism of proteins."  In practical terms, insulin is needed to escort the carbohydrate (which has been broken down to glucose) into working cells to "fill up the fuel tank."  Since the stored form of glucose (glycogen) can be reduced by as much as 40% after resistance training, insulin due to carbohydrate ingestion post exercise plays a big role in replacing that which was used up.  But it does more than just refill the gas tank.

Ingestion of high glycemic index carbohydrates has been shown to elicit an insulin spike that can increase the availability of growth hormone, which is vital to tissue and muscle growth and repair.  Dr. Greg Haff, et al., explains in their review of carbohydrate supplementation and resistance training that: "The elevations in growth hormone stimulated by carbohydrate supplementation may ultimately lead to increases in muscle hypertrophy and enhanced resistance training performance."

Recovery from training exists on a continuum.  By this, I mean that recovery is directly influenced by anabolic (tissue growth/repair) as well as catabolic (tissue breakdown/degradation) hormones. High intensity exercise has been shown to increase levels of cortisol, which is a catabolic hormone. Cortisol acts to stimulate the breakdown of muscle protein and simultaneously prevent synthesis of new muscle protein. The unfortunate icing on this cake is that cortisol acts more catabolic on type II
muscle fibers
, which are the primary muscle fibers used in strength and power movements. If cortisol levels remain elevated for an extended period of time, muscle atrophy and reductions in muscle power and strength can occur. Cortisol has also been shown to impair the function of the immune system. Reductions in immune function may open up the doors to illness or slow and limit the recovery process. But...carbohydrate supplementation post exercise has been shown to elicit insulin-mediated reductions in cortisol. So supplementing with carbohydrates post exercise may not only refuel the tanks, but also increase the availability of growth hormone while simultaneously clearing the catabolic and immune suppressing effects of cortisol. How can something that does all that have such a bad reputation?

Dr. Haff, et al., in the conclusion of their review of carbohydrates and resistance training, state that carbohydrate supplementation before, during, and after training:
   "may serve to promote a faster recovery, which may enhance subsequent exercise and training sessions"
   "offer some ergogenic benefit, through increasing work output when the athlete is performing high-volume training with moderate loads"
   "effect the overall net protein synthesis rate postexercise, which could magnify the hypertrophic response to training."

He also explains that all these effects of carbohydrate supplementation may add up to better quality training sessions which could ultimately improve performance for Power Athletes. 

Let's now apply what we have learned, young athlete. So now on to the specific timing of carbohydrate ingestion and supplementation...
Generally speaking, before exercise, as well as just about any other time except immediately post exercise, carbohydrates should be "complex" or low glycemic index. During as well as immediately post exercise; however, carbohydrates should be simple/high glycemic index in nature to provide quick fuel and promote refueling.

I've explained that high glycemic index carbs post exercise increase refueling as well as promote recovery by increasing anabolic hormones and decreasing catabolic hormones, but these effects can be even greater when the carbohydrate is combined with protein.

The combined effect of these two macronutrients post exercise does a few things such as: Increase the amount of "refueling" that can occur, limit the amount of muscle protein that is degraded, and increase the amount of muscle protein that is synthesized.

SO combine those carbs and protein post training! And keep the carbs low to moderate on the glycemic index unless you are working out or you just finished.

-Kevin Kuhn


Haff, G.G.  (2008). Carbohydrates.  In J. Antonio, 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

Haff, G.G., Lehmkuhl, M.J., McCoy, L.B., & Stone, M. H.  (2003).  Carbohydrate Supplementation and Resistance Training.  Journal of Strength and Conditioning Research.  17(1).  187-196.

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