Thursday, December 10, 2009
Protein, Protein, Protein… What’s the hype about?!
Athletes and non-athletes alike have a common misconception about protein. The misconception goes something like this; “athletes need A LOT of protein in order to gain A LOT of muscle.” If this is what you think, ask yourself how do athletes get larger muscles? Don’t get me wrong; there are certain groups of athletes that need more protein than the typical, sedentary adult, but for different reasons, which I will discuss shortly. Have you ever gone to the gym and overheard the rather large, muscular athletes lifting free weights talking about protein and protein supplements? I realize that this may sound like a stereotype, but this is a group of athletes that typically believe that they need to consume an excessive amount of protein in order to be bigger. It doesn’t help that the media and muscle magazines have tons of advertisements pushing their newest, greatest, and not to mention $expensive$ protein supplements. At the other end of the gym, you may have overheard cardio athletes talking exclusively about carbohydrates. And there you are asking yourself, what is the right balance for me? I would like to clear up this misconception and any other confusion about protein.
Before I dive in, let’s address the question I left with you above. How do athletes get larger muscles? Well, obviously it isn’t from eating an excessive amount of protein. Athletes get larger muscles from resistance exercise, such as lifting weights, doing pushups, etc.
Protein 101…we have to start with some basics about protein in order for you to understand and appreciate protein. I’m sure you have heard of amino acids or essential amino acids. Common, I know you know of at least one! After Thanksgiving, I’m sure you have heard of tryptophan? Tryptophan is an example of one amino acid. But, do you know what they are? I won’t get into their chemical structure, but in essence they are the “building blocks” for protein. Think of them as Lego pieces. Do you know how many amino acids are used in the human body? Take a guess… 20. Eleven amino acids are made by the body and are called nonessential, meaning you don’t have to consume them through your diet. However, the other 9 amino acids are essential and therefore, you HAVE to obtain them through your diet (1). Now, you may be wondering how to obtain these necessary amino acids? Let’s look at sources of protein…
There are animal and plant sources of protein. We can then categorize them into “complete” and “incomplete” proteins. Complete proteins are those that contain ALL 9 essential amino acids. Animal products such as meats, fish, eggs, dairy products, and soy (plant protein) are considered complete proteins. An incomplete protein does not have all essential amino acids. Examples include plant sources such as, legumes, beans, nuts, seeds, vegetables, fruits, and grains. To my vegetarian readers, do not worry! You can obtain all of the essential amino acids! You probably do it everyday and don’t even realize it. By combining two or more foods that lack essential amino acids (incomplete proteins). For example, beans and rice (legume and grain). In the nutrition world these are called “complementing proteins.” (1, 2).
Okay, you just ate a meal containing protein. Your body breaks the protein down into amino acids and then what happens? These amino acids get used to form new proteins to be used throughout the body. Protein has a lot of amazing functions in the body!! These proteins can be used for the structure of muscle, bones, ligaments, tendons, hair, nails, skin, and organs. Proteins can also be used to make enzymes, hormones, and antibodies, which help with immune function. Finally proteins are used to transport substances, maintain fluid balance and acid-base balance within the body, but I won’t go into any further depth with all of these functions (1, 2, 3). Hopefully, you can see with all of these amazing functions why protein is important.
Ah yes, but what about for the athlete? There are a few “extra” functions for the athlete. Protein can be used to repair damaged muscle and build new muscle tissue. There is one more function. Can athletes burn protein for energy? Only under certain circumstances. First, athletes burn carbohydrates and fat for energy (NOT typically protein). Once these sources are depleted, the body will then use a small amount of protein for energy. AND this only happens to particular athletes: endurance athletes (marathoners, ultra-marathoners), athletes involved in very intense exercise and athletes not consuming enough calories (dieters). Burning protein for fuel is not as efficient as burning carbohydrates or fat due to the chemical reaction to break it down. AND look at all of the functions above; don’t you think it would be a waste to burn it?! Take note: the body does NOT store protein like it does with carbohydrates or fat. For example, there is not a special or magical storage place just for protein. If you eat more protein than you need, it gets stored as fat or glycogen (storage from of carbs) (2, 3).
HOW much protein do I need??
Most people and athletes in our society consume more than enough protein. Although, there are certain groups of athletes that need more protein than the average person, which include:
• Endurance athletes & intense exercisers
• Dieters- restricting calories and intake
• Youth & Teen athletes- need protein for growth and muscle development
There is scientific evidence that athletes need more protein than sedentary people, remember why? Look above at functions for the athlete. However, there is no scientific evidence that consuming more than 2 g of protein/kg provides any physical advantage (2).
Daily Protein Recommendations:
Sedentary adult 0.8 g Protein/kilogram
Recreational exercising adult 1.0-1.5 g Protein/kg
Endurance athlete, adult 1.2-1.6 g Protein/kg
Strength training adult 1.5-1.7 g Protein/kg
Growing Teen athlete 1.5-2.0 g Protein/kg
Recommendations from Clark, N. Nancy Clark’s Sports Nutrition Guidebook (4th ed.). 2008.
Let’s do an example to help you understand. I suppose I will use myself…
I am an endurance adult athlete; I am going to use the range 1.2-1.6 g Protein/kg.
1.2-1.6g Protein/kg X 57 kg = 68-91 grams of Protein/ day
I would aim to consume the lower end of the range, 68 to 78 g of protein per day because I am a female and since my total daily and weekly mileage is not high yet. As my mileage increases I will need to increase the total amount of calories I consume and I will more than likely increase my protein intake.
*To get your weight in kg, divide lbs/2.2 example. 125lbs/2.2 = about 57 kg
Have I consumed 70g protein today?
Breakfast- Whole wheat bagel 10 grams Protein
Egg 6 grams Protein
Raspberry yogurt 5 grams Protein
Lunch- 1 % milk 8 oz. 8 grams Protein
2 slices whole wheat bread 10 grams Pro
Peanut butter (1 Tbsp.) 4.5 grams pro
Large Banana 1.5 grams pro
Dinner- Chicken breast roasted, 4 oz. 35 grams pro
Brown rice, ½ cup 4 grams pro
Broccoli ½ cup 2 grams
TOTAL= 86 grams of Protein
As you can see, I easily consumed more protein than I need.
What about consuming protein right after a workout?
It is very important that you re-fuel your body after a workout. Again, I will write a separate post about post-exercise nutrition. Remember, carbohydrate is the key fuel source, so you should be consuming carbohydrate rich foods after a workout. Although, there is some scientific evidence that suggests that a small amount of protein should also be consumed after a workout because it can help with muscle recovery after endurance and weightlifting exercise (4).
How much is this “small amount of protein?” About 0.1-0.2grams/kg (4)
Using myself as an example again: 0.1-0.2g/kg X 57kg = 6-11 grams of Protein
An example of post-exercise snack I enjoy is a glass of chocolate milk, which would contain 8g of protein/8 oz. or sometimes I enjoy a Clif bar, which has 10g of protein/bar.
In summary, protein has many important functions and is an important nutrient for athletes. Protein is especially important for endurance athletes (marathoners, triathletes) since it can provide a source of energy. And, yes, athletes involved in endurance, strength, or team sports do need slightly more protein than the average, sedentary adult. Most of us do consume more protein than we actually need, as you saw in my example. Finally, there is no need to purchase expensive protein supplements when you can obtain the recommended amount of protein through food. Most foods that contain protein have other important and valuable vitamins, minerals, and phytochemicals. Think about it, the cost of a protein bar alone is going to be just as much as a jar of peanut butter, which could last you an entire week!
1. Hedrick Fink, H., Burgoon, L. A., & Mikesky, A. E. (2009). Practical applications in sports nutrition (2nd ed.). Sudbury, MA: Jones and Bartlett Publishers.
2. Clark, N. (2008). Nancy clark’s sports nutrition guidebook (4th ed.). Champaign, IL: Human Kinetics.
3. Benardot, D. (2000). Nutrition for serious athletes. Champaign, IL: Human Kinetics.
4. Dunford, M (Ed.). (2006). Sports nutrition a practice manual for professionals (4th ed.). Chicago, IL: American Dietetic Association.