Thursday, November 25, 2010

It took a while, but here it is

So last I left off I was talking about how the increase in red blood cell count would increase the potential amount of oxygen your blood can carry at a given time, would this increase VO2Max? Theoretically it should right? Noah provided a good short reading from JAP in the comments of the last post on the trainability of VO2Max, maybe a good post for next semester when I'm taking the 2P09 physiology class.

The importance of red blood cell count is pretty easy to understand, a red blood cell has a pigment called hemoglobin that has a heme (iron) component responsible for the red coloration of the blood as well as the color of what we excrete after it's broken down and a globin (protein with 4 polypeptides) component. The oxygen binds to the iron component and the amino acids of the polypeptide component bind CO2 to be carried away from the tissues and out by way of the lungs. There are 4 heme components per red blood cell and each one can carry one molecule of oxygen, when oxygen is bound to hemoglobin it becomes an oxyhemoglobin. The reason that carbon MONOxide poisoning is so dangerous is because the iron of the hemoglobin has a higher affinity to carbon monoxide than it does to oxygen, the hemoglobin will pick up carbon monoxide and it will take up one of the 4 spots it would have for oxygen. The more carbon monoxide that a red blood cell picks up, the less oxygen it can carry, you're slowly suffocating yourself.

So, more red blood cells means more oxygen can be carried in the blood at a given time, which means more fuel for the working muscles and because road and mountain bike racing require big aerobic efforts and use up quite large quantities of fuel, the more oxygen they have at their disposal the better. How can we get more of those little red things? A red blood cell is also called an erythrocyte and the production of erythrocytes is called erythropoiesis. There are cells in the red bone marrow with receptors for a certain hormone, when this hormone reaches those receptors it stimulates the cells to transform, multiply, and synthesize reticulocytes secreted into the blood and eventually (1-2days) it loses its remaining polyribosomes and becomes a mature erythrocyte. It would make sense that the hormone would be called erythropoietin (EPO), it's secreted by the kidneys and liver when it sense a state of hypoxemia; a deficiency of oxygen in the blood stream. The reason for the lack of oxygen could be from a number of things, but when you're exercising hard and blood can no longer keep up with the large oxygen demand of the tissues they enter a state of oxygen deficiency called hypoxia. When there is less oxygen in the air (lower partial pressure), such as at a higher altitude, the kidneys are already sensing a state of hypoxemia even before training begins and the body adapts by increasing hematocrit, or red blood cell count, to accommodate the needs of the body's tissues.

As you all know, for some, EPO doesn't come solely from the kidneys and liver, you can call these people blood dopers, although they aren't the only kind. Everyone has heard the famous quote from Dr. Ferrari that "EPO is as safe as orange juice", well not that I'm pro-doping in any way whatsoever but from a physiological point of view he's right. EPO will increase hematocrit, or how much of the blood do erythrocytes make up, and therefore make the blood thicker and harder to pump, but unlike the lungs, the heart is trainable and can overcome this disadvantage. The heart is trainable because it consists of a thick layer of myocardium, or muscle of the heart, that can increase the strength of each contraction, the ventricles stretch more each time they dilate and the more they stretch the stronger the contraction because it has more blood to eject. An endurance athlete should have a low resting heart rate because, at rest, the heart can supply the body's needs in fewer beats in one minute than it could if it wasn't trained. Also, drinking more water will make the blood thinner. Although EPO is safe, it's not like you can take as much as you want without any bad effects because too much of anything, even orange juice, can have negative effects.

Orally ingesting EPO isn't the only way to raise hematocrit, when you're testing to see someone's hematocrit you have to remove a sample of blood and spin it in a centrifuge. Once the plasma has been separated from the formed elements you can remove the formed elements and re-inject them into the blood stream. Another very popular method of blood doping is to have a training camp for an extended period of time at high altitude and the "athletes" will get many tests done to keep checking their red blood cell count, the higher the count the better the blood. However, they also have to make sure that the level does not exceed the legal limit set by the UCI which is 50%, on average a person's hematocrit will be roughly 45%. This isn't a relatively large increase but a 5% gain makes a HUGE difference when it comes to endurance training and racing. Once the team "doctors" are satisfied with the number, they remove the blood and store it at the proper temperature, those clear bags in the fridge contain red liquid gold when you're 14 days into the Tour and every energy source in your body is being depleted as you speak. A fresh bag of quality blood is more than the body could ever ask for.

So, maybe after reading this you feel like doping, if that's the case then I'm very sorry but you were a cheater at heart anyways so I take that back because I'm not very sorry at all. Either way, having proper knowledge on blood doping and knowing exactly how to do it is one thing, the equipment involved is expensive as hell, it's very time consuming, it has to be done properly each and every time with absolutely no error in execution. Think about a screw up like giving person x's blood that is type A to person y who has type B blood, yeah, not good. BUT I can tell you that proper nutrition can help to increase red blood cell production; of course there's iron seeing as it's the reason the blood is red so must be kind of important, also, vitamin D and folic acid promote rapid cell division and DNA synthesis and there's vitamin C and copper that are cofactors for some enzymes that synthesize hemoglobin.

SOURCES: PEKN 1P90 course notes & Physiology and Anatomy 5th Edition by K.S. Saladin

Friday, November 19, 2010

The time has come

I told myself that the day I couldn't walk my dog over to the park, play, and come back without feeling out of breath would be the last day that I would be totally physically inactive. Well, today I walked in the door with my head down as I tried to hide my deep breathing, so why am I out of breath? You've heard it just as often as I have "I could hardly breath" or "my lungs couldn't take it anymore". Well, although that is how you FEEL, it is not what is occuring from a physiological standpoint. Your lungs are providing your body with enough oxygen but due to reasons such as nitrogenous waste build up in your muscles, the oxygen being delivered to your muscle tissues is insuffice. Even with no metabolic by-product build up, you're feeling out of breath because your tissues are depleted of oxygen, not because you aren't breathing hard enough. So, it's not that YOU are out of breath but your tissues are out of breath so to speak.

You're going to feel as though if you can just inhale a little more air you'd be able to keep the effort or take it up one more knotch, you're breathing harder and harder as you ramp up the effort but no matter how hard you breath you're still feeling out of breath, don't try and take deeper breaths. Breathing rate and strength will increase from sympathetic stimulation triggered by insuffice oxygen (fuel) being delivered to the tissue, so long as your breathing isn't abnormal then you're fine.

Why can't the lungs be trained? Because the lungs are not muscles, plain and simple, think about it, if your lungs were able to take in more air then they would need to get bigger, if they were able to get bigger then they would have the potential to outgrow the cavity in which they lie. You can argue that the muscles involved in respiration can be trained, notably, the diaphragm, external and internal intercostals, and the transverse abdominus during forced exhalation. But, these will not increase your vital capacity (amount of air you can inhale and exhale during maximal inhalation and exhalation), they MAY be able to increase the force at which the air enters the lungs but not the amount of air. This would have very, very little, if no significant effect on performance because the diaphragm and intercostals don't have a hard time inflating a couple of bags with air to begin with anyways.

If your lungs are taking in enough oxygen then why are your tissues not getting enough? Well, as I mentionned previously, it could be a build up of metabolic waste that is inhibiting exchange and overall muscle function for other reasons that can become a whole new discussion of their own or your blood isn't able to bring your muscles enough fuel. Therefore your tissues are in a state of hypoxemia and a message is sent from your brain to your heart telling it to increase cardiac output because increasing blood flow is how your body increases the rate of nutrient delivery. Vessels that do not supply your working muscles become constricted to increase blood flow to the muscles that need it most, this is why if you were lying on the couch and you were to get up and do some sort of intense physical activity right away if would feel like your lungs are about to collapse.

VO2Max will come into play for delivering enough oxygen to the working tissues as well because it's the effeciency of O2 uptake, this is not trainable either. If you're VO2Max is as high as Trevor's then you don't have to stress yourself out about it but if it's somewhat low, no worries, there are ways to overcome it. Most importantly, increasing red blood cell count, or how much oxygen is being transported in the blood and makes its way to the tissues in need.

So, how to we increase red blood cell count? Well, that is also a whole other discussion and within the next couple days I will post up the process of producing red blood cells and the legal and illegal ways of going about doing it.

*Note: I am by no means an expert on physiology but I do think I have a pretty good understanding of what I've learned so far, feel free to add to or argue what I have written*

Friday, November 12, 2010

Crunch Time

Every semester there is one week that is just rediculously overloaded with stuff to do, well that happens to be next week for me. Three big midterms worth about 20% each (different classes of course) in four days, plus a 10 page project I've yet to start and some French work thrown in there. It could have come at a little better time, like say next week so I can do one more race this weekend to attempt to end the season on a somewhat high note but at this point it seems pretty much impossible.

On top of all the work due next week I picked up a shift Saturday night because this season and schooling has left me with roughly 87 cents in my bank account, so not only do I not have the time but I don't have the money either to race this weekend. My funds wouldn't have lasted me through the season if it wasn't for the support from my rents, Chown, Liberty! and many more people who have helped me here and there along the way so big thanks to all of them, you know who you are.

I which I could say something like "well, it's time to relax and sit on the couch for a few weeks before I start getting back into things" but it's more like: Well, it's time to go ape shit for the next couple weeks to try and get all my work done while trying not to OD on caffeine then I can relax for a bit while I wait around for my 19th birthday! Then it's go time for a few days then I've got some finals to study for, so far it looks like I might hit 180-185 by the end of December, maybe I'll try and loose a few of those pounds before 2011 race season comes around, but who knows, the only off-season goal I've set for myself so far is doing the Belly Buster challenge at M.T. Bellies, many brave men have tried and failed, I've just got to focus on building up the courage and going for it.

Tuesday, November 9, 2010

CX Nationals

Well, not much to report on this one. I thought I was feeling alright the week leading up to it, the course was pretty quick so I liked that, it was a good thing I met up with Chown before the course pre-ride because he passed me a rear wheel, big thanks for that.

I was called up first row because I registered early, felt pretty good at the line but when the gun I went I just seemed to go backwards. From there on it was just falling further and further behind until I was one of the last guys, I got pulled just before the start/finish on my second last lap. He wouldn't have caught me but the 80% rule was in effect, I was happy to be done. Not sure what's going to happen this weekend, I would really like to hit up the KB race but I have 3 mid terms next week starting Monday so a solid few days of studying will be needed.

Huge props to Perry for his National Title.

My tubular tire still isn't reglued from when I rolled it at Parma in warm up so I need to get on that before this weekend for sure if I'm going to race. Tomorow could be a hard effort in the dark with the St.CCC folks, should be fun.