Hello everyone, welcome to the third portion of this nutrition segment. So far we have spoken about how carbohydrates and fats circulate and are used in our body. If you have not read the other articles please do so HERE:
Now it is time for one of my favourite topics. That is a lie, I find ALL nutrition very entertaining and ruthlessly plunge into whatever information I can find on any related topic. But let us get on with it.
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So what is a protein? Well the simplest answer is as that a protein is a basic building block of life and that without it we would not even exist. So before I put you all to sleep let me first demonstrate the importance of proteins with a few examples. Let us start deep within the body, slowly becoming more superficial so that everyone can understand how proteins affect every level of our biology. First let us start with DNA. Our personality and our physical traits are determined by a complex code of nucleotides that determines everything we think we know about ourselves. This alpha helix structure is primarily proteins with a sugar-phosphate back bone. Just like how a triglyceride has a glycerol back bone and fatty acids attached to it, as discussed in the last "Fats" article., DNA has the same general structure. A backbone with proteins that stem from it and connect with other proteins that form a twisted latter shape. So thanks to protein, you are who you are. If you do not like who you are I suggest going to a genetic engineer.
Figure 1: DNA- as you can see the four proteins that attach and create the “rungs” of the latter
As if this does not demonstrate the importance of proteins enough let us go up a level to the cell. In the last segment I discussed how the basic structure of a cell is a double layer of fatty acids. Well this is a very general and over simplistic view of the cell. Imbedded into the fatty acid layer are “boulders”. These “boulders” act in multifaceted ways which life could not exist without. They are able to increase the structural integrity of the cell because they are held together by stronger bonds then the fatty acids, which in the last article we explained move slightly to help the cell function. Some of these “boulders” form tunnels right into the cell and act as a door way into and out of the cell. Nutrients and hormones can come into the cell and unwanted particles can leave the cell so it does not overfill with waste. Wouldn’t want to be constipated on a cellular level would you? A lot of these “boulders” allow for hormones to attach to the cell and cause a signalling cascade to happen in the cell. An example of this would be how Epinephrine causes a signal to Hormone Sensative Lipase to start breaking down fat, which I discussed in the last article.
Figure 2:A section of the phospholipid bilayer. You are unable to see the glycoproteins however they look similar to the “charbohydrate chain” as seen above.
Some of these boulders have long projections sticking out and allow it to communicate with other cells for various reasons. One example would be that a virus can look like a cell and act like a cell but because these projections exist then it allows the cell to say “ Hey wait, this cell does not seem familiar, let’s get rid of it.” Without these projections then we would get sick very quickly considering how everyday bacterium tries to infiltrate our body. It is up to these “boulders” and projections to keep us safe. If you have not guessed yet, these “boulders” are proteins.
Let’s move up yet another level for all you athletes and coaches. Muscles are made of proteins as well, which for most is nothing new. To imagine how a muscle contracts let’s look at a gymnast climbing a rope. The gymnast’s name is Myosin; he’s foreign. And he is climbing up our 28 foot rope whose name is Actin. Myosin has to get to the top of the rope and to do this he will place his hand higher on the rope then he is currently, use his muscles to pull himself up, then repeat until he is dangling from the rafters and hit that bell that so many gymnasts hate to hear. The muscle works the exact same way. Myosin proteins pull on actin proteins pulling them closer together. We humans with our brutal vision, due to sitting in front of the idiot box all day, cannot see these small microscopic events. However we can see the result of thousands of actin and myosin proteins pulling on each other so that they all slide a bit closer together. We call this muscle contraction.
Figure 3: actin and myosin sliding against each other to shorten the “H” zone which is done thousands of times along the muscle fiber and causes it to shorten.
I will write a article with more information on this process later, but for now let us get back to the topic at hand; proteins. Our last example will be one that we all know so well, or not so well depending on your hairline status. Keratin is a protein that is found in nails, skin and yes, hair. We cannot see the individual proteins but they are a major part of our physical appearance, which we know is extremely important in this day and age.
For a gymnast protein is somewhat important because it helps to build muscles as we now know. The more protein in the system the greater the weight each of those micro movements can pull. As we discussed, it is like a rope climb and if you are packed full of proteins then your "rope climb" is faster and can pull heavier weight without breaking. It is important to note that muscle proteins are as long as the entire muscle! Imagine your muscles like long strings of spaghetti one attached at one end of the bone and the other attached at the other. (Terrible over simplification but, please researchers, don't kill me, it's for younger athletes afterall:p. The reason muscles get "bigger" is because you add more spagetti and the current spagetti becomes thicker with fluid that holds the substrates inside.
Sarcoplasmic Hypertrophy referes to the concept of thickening the muscle. Myofibrillar Hypertrophy refers to the addition of new spaghetti strings ontop of the current ones. Both of these mechanisms make you stronger. A gymnast needs Myfibrillar more the sarcoplasmic. We are an explosive sport so it is better for a gymnast to be able to lift 1000 lbs 3 times then 100lbs 50 times. Sarcoplasmic Hypertrophy simply increases the energy system abilities as we have discussed in this series and Myfibular Hypertrophy increases the force of the contraction.
Figure 4: The difference between Sarcoplasmic and Myofibrillar
So now we all know how important proteins are, let us look into the structure of these important little building blocks. You can imagine these building blocks like a nice little bead bracelet bunched up in someone’s hand. As you look from a distance it looks like one large ball. However when you get close you can see that it is made up of lots of little individual beads that and are strung together by a string. Each bead is called an amino acid. Amino acids are the base of all proteins and depending on what types of beads are strung together, how many are strung together and what way they are held in the hand, they can do many different things. Any protein can become a keratin protein, a cell membrane protein, a transport protein as discussed in the last article. It soley depends on how they are made. The topic of protein synthesis is a very long and dreadful discussion that simply does not apply to many people that do not study them as a career. I will skip this part for the sake of boring everyone and if you would like a specific article tailored to this topic leave me a comment. So why are amino acids different? This is a complicated and a simple question all at the same time. Every amino acid has the same basic structure as you can see below.
Figure 5: structure of amino acid- these are linked together to form polypeptide chains-these are folded to create proteins-proteins are clumped together to create enzymes and receptors etc.
The only thing that gives different amino acids different properties is the chemical properties of their “R” group, or side chain. This can be anything from a simple single carbon with a three hydrogen’s or can be slightly more complicated with a thiol group which we discussed earlier- For those too lazy to look back a Thiol group is a sulfur molecule that has a lot of energy that can be used for metabolism in specific pathways. The string that holds these beads together in our analogy is called a peptide bond and is formed by taking away a water molecule. These bonds can be easily broken as well by adding a water molecule. There are 22 different amino acids that are used to create proteins or are used for energy. For the purpose of this series we will focus on the breaking down of the protein for energy.
All amino acids can be broken down and put into other processes. Here are a few examples. After breaking down Tyrosine, one of our 22 proteins, many chemical reactions can occur to create fumerate. Fumerate is one of the chemicals involved in the citric acid cycle (Krebs Cycle). This can be used to fuel exercise. Breaking down certain amino acids can increase substrates to glucose, Krebs Cycle and ETC pathways, all of which we have discussed in previous articles of this series. This is used a lot during exercise for any athlete who depletes their CHO stores. Even though the NH2 group has already been used, the rest of the amino acid can be converted into a keto acid and put into the Citric Acid Cycle . In the liver, Glucogenic Amino Acids can be converted into alpha keto acids and used in glyconeogenesis ( formation of glycogen) to be put into glycolysis, CAC and then ETC.
Some of these include Valine, Serine, Glycine etc. Tryptophan is a precursor to creating serotonin, a neurotransmitter that has been shown to increase happiness. All amino acids have different pathways they can all enter but to go through every one of them would be excruciating and, simply, I do not know them all anyways. If you look at the ingredient label of a protein supplement it gives you a whole list of proteins that it contains. The idea is that by increasing certain ones, that it will give athletes an advantage to building muscle and help the body to prevent breaking down muscle. The conclusion is that the more of these substrates that are in the body, the more fuel the body has to use before it has to take it from the muscle, which no athlete wants of course.
Nitrogen balance is the input of nitrogen compared to the output of nitrogen. This refers to an athlete muscles. If the athlete does not intake enough proteins and is exercising the body is said to be in a negative nitrogen balance. This means that the NH2 groups are running low in the muscle because it is being all used up to be put into the other processessuch as CAC or ETC. In a sedentary human this is not a huge problem because proteins usually do not need to be used because enough CHO and fat is available. For an athlete however this may be a problem. If the nitrogen balance is negative it means the body actually has to break down muscle to use for energy. An athlete wants to be in a positive nitrogen balance as much as possible. This means muscles are being built and amino acids are being added, ie. Hypertrophy. When an athlete exercises their nitrogen balance naturally drops a bit and usually an athlete will eat proteins before, during after to “feed” the muscle and spike their nitrogen balance. It is always a balancing act with proteins in the muscle. Can you have too much? NAW, not really. Many research articles have been done and even giving someone up to 4,000 mg per kg has not shown any detrimental effects on the body. That is a lot of protein considering the Daily Required Intake is 80mg/kg of body weight. The body uses whatever protein it can use, depending on the primary fuel source of each athlete. The left over is converted into urea as discussed earlier. If the body is unable to use protein it simply just increases the amount of urea made. Vitamins are the same. You cannot over dose on a vitamin for this reason, unless you are really trying to. Anyways, long distance runners will be able to use proteins more efficiently then a sprinter. A long distance runner almost always has to tap into their protein stores to get through a race near the end. When the protein stores are used up it is called “hitting the wall”. This is when a sprinter just collapses and is out of energy.
A sprinter uses the Creatine system for energy because it is usually under 10 seconds. Creatine is a nitrogenous acid that can create a lot of energy very quickly for the cell. The downside is that it is used very quickly, within 10-15 seconds. It takes about 10 minutes to replenish Creatine stores fully. Sprinters barley use fat, never mind protein to fuel the exercise. He or she does not have to. A sprinter will use glycogen stores up as he or she uses creatine stores to get an extra push. If the athlete is not use to using protein then he or she will not have as many enzymes that can perform protein breakdown and transport because the body does not need it as much.
I have discussed many different pathways here and the conclusion is that all coaches need to understand the pathway that their sport requires. How do you know? Well it depends on the requirements of the sport. Here is a few ways to tell:
If the sport requires a lot of explosive quick bursts of power such as hockey or sprinting then creatine and glycogen are the main energy providers.
If the sport is a long distance but low intensity sport then fat will be the dominate fuel source after CHO is used up. This would include any long distance running or swimming. For extremely long sports protein will come into play at the end as a last kick to finish the race. The burst to the end is the creatine stores being used up by a long distance athlete.
Lots of sports that require a bunch of different forms of exercise such as hockey and soccer, where the athlete may be coasting, sprinting, changing directions etc. It is safe to give them a well balanced diet of everything. He or she will need all of them.
These are a few ways to determine what nutrient is most important for your athlete but at the end of the day it is very simple and a lot cheaper than any manufacturer will tell you. Here are the take home messages of this series:
1) Have a well balanced diet from all four food groups and an athlete should be eating more than the average person to fuel the extra exercise. Focus on carbs
2) All processes go hand in hand with each other so do not limit to certain diets that “focus” primarily on fat or protein or CHO.
3) Athletes go from Creatine to CHO to Fat to Protein to Ketones in the brain. Depending how long the exercise sessions of your sport are you can determine what nutrients are more likely to be needed. If you are using Ketones you need to stop immediatly. More on ketone diets later.
4) Do not stuff your face with proteins, CHO or Lipids. The body can only handle so much at once. You can keep cramming but you will only store the food or release it as waste. For CHO the body can only digest about 1 gram per kg of body weight per hour. So do not waste your time and get Gastro-Intestianal distress by having 5 plates of pasta before a game. Protein does not seem to have a limit but again only so much protein can be used. Honestly I am not sure what the limit of protein is, if there is one. It should be noted that fructose, fruit sugar has only 2/3 transporters that can help digest the fructose int he intestines. Glucose uses other transporters. Research shows that if you were to use fruit and carbs that you would get maximum benifit without distrupting or jamming your transporters. If you have to much fruit before training you will get intestinal distress because the transporters are filed up but you have sugar still that actually is corrosive to the body. This is why people with diabetes get their arms and legs cut off or their eyes malfunction. The extra ACID in the blood; ie glucose eats away at the body. Fructose is similar in hgh doses. Have an apple or something but don't have a huge plate of strawberries and grapes before training. I have done this and it hurts.
5) If you can during the sporting event, try to get more CHO and Proteins in the body to keep the substrates plentiful for all the processes. Fat takes too long to digest and be put to use to gain any real benefit from it on the fly. So just stick to Protein and to Carbs- Little bits like a protein bar and SMALL protein shake (Not too much fluid).
6) Eat after the event if you can to replenish the CHO, Fat and PRO. Stores to keep nitrogen balance positive so protein is not broken down during rest. This is important because if you allow the body to remain in a negtive nitrogrogen balance consistantly you simply are not making the most use of your time in the gym. You gain 10 points of strength lets say but then you lose 6 and have a remainder of only 4. If you make a habit of eating before, during and after that "4" can become more like a 6 or 7. (generaic metrics to show a point)
THE MOST IMPORTANT ONE: 7) Do not go crazy over your nutrition. Some people find that it helps, some do not. The most important aspect of the sport is to have fun and love what you do. Sometimes these things such as nutrition and proper post training “do's” and “dont’s” go a little too far and take away from the sport for little gain. Keep yourself eating plenty and eat proper food but some athletes find the need to measure to .1 of a gram and time themselves and go to some pretty ridiculous ends to do well in their sport. If you love to do that and that is your thing then great, have fun, just do not let nutrition run your life. A happy athlete with a few beers in him or her will always go farther than a frustrated athlete, no matter who how good their nutrition is.
Hope you all enjoyed the series. Please share with your friends!