My favorite part of exercise physiology was learning about the way that my muscles and body actually worked on a molecular level.  As a biochemistry major at Union I have been exposed to an array of knowledge from cellular peptides and their composition to the thermodynamics of a carbon bond.  What I missed, though, was information about my every-day life as a whole, and how science impacts it.  As a former athlete, I enjoyed learning about my body’s fuel utilization the most.  While I was not able to put any of my knowledge into effect this year, I hope to be able to in the future.  The intricacies and habits of our body far exceed what I was thinking of on a surface-level, and this class enabled me to better myself both physically and mentally.  I believe that is the most important aspect of learning – not just the knowledge aspect, but also being able to apply it.  This course gave me the relevant knowledge I needed to apply certain methods and advantages to my every day life.  That, to me, is more valuable than any face-value knowledge available in books, lectures, or labs, and is why I enjoyed this course so much.

In the past women have been directed not to exercise by their primary care physicians, peers, and scientific researchers.  With the rise in popularity of elite female athletes, however, this predisposition is being called into question.  A news article in the Washington Post delves into the (relatively) new rise in exercising while pregnant, the risks involved, and any connections to complications during pregnancy and labor that intense exercise may have on an individual.  This interest has been brought up by many female athletes such as Serena Williams, Beth Rodden (a Mountain Climber), and Alysia Montaño (a world-class runner) who have not only competed while pregnant, but have managed to excel in their sports while in different stages of their pregnancy.

One might think that exercising while pregnant could be harmful to the fetus, because it would increase the levels of CO2 in the blood as well as lactic acid and even free radicals.  Studies by the University of Iceland seem to put science on a tract to disprove this notion.  Of all of the test subjects in the exercise and non-exercise groups there was no significant difference in the pregnancies between the individuals who exercised and those who did not.  While the study was too small to come to any firm conclusions about the population as a whole it could be hypothesized that exercise does not, in fact, have any negative side effects on someone’s pregnancy.

I have thought through the article, and have come to some conclusions myself.  One women made a statement that I feel is important to take note of.  Margie Davenport, of the University of Alberta, stated that it “We need to start changing the conversation away from what are the risks of exercising during pregnancy to what are the risks of not exercising during pregnancy.”  I feel that this is an important comment, because it pushes the readers of the article to stray from the traditional notions.  I agree with her, and I feel that exercising while pregnant is important to the health of the mother and her unborn child.  However, I also feel that women who are not used to exercising should be more cautious.  If someone – not only a pregnant women – jumps right into high-intensity exercise it could increase a risk of cardiovascular or skeletal injury.  This type of incident would put the child and the mother at risk.

So, I stand by Davenport in saying that it is important for women (pregnant or not) to exercise.  Given that there is not any known risk to exercising while pregnant, I would suggest anyone who is pregnant to continue their workout regimes or even start new ones – as long as they are safe about them.  Exercise can help reduce stress, and improve the overall health of those who utilize it correctly, and these are benefits that could even assist someone in the entire pregnancy process.

The idea that lactic acid buildup causes muscle fatigue is preposterous.  Lactic acid buildup is not only irresponsible for the fatigue and decreased muscular performance, but rather other sources of fatigue can be discovered in different muscle groups.  During performance it can be observed that the excitation-contraction coupling steps are impaired when under high stress.  One example of this can be observed in the transverse-tubular system has a buildup of potassium ions.  This system is in the direct vicinity of muscle-fibers, so a buildup of ions during exercise would impair the muscle fibers’ abilities to keep sodium ion equilibrium.  A buildup of inactive sodium inside the fibers leads to the inactivation of action potentials, and in turn a slower functioning muscle fiber. 

Another explanation for the fatigue and limited performance of muscles can be observed in the accumulation of metabolites coupled with a limited level of substrate.  When muscle fibers (especially fast-twitch muscle fibers) exert energy, they utilize a wide variety of substrates to fuel themselves.  In many cases, a great increase in energy use in fast-twitch fibers can cause  ATP in the tissues to decrease to extremely low levels, and subsequently a decrease in the glycogen stores as the cells try to keep up with the rate of ATP use.  

Since lactate does not affect the excitation-coupling steps it can be determined that it is not responsible for muscle fatigue.  The higher level of hydrogen ions do not lead to any change in the pathway, or a greater production of metabolites that would lead to muscle fatigue.  It could even be argued that the lower pH brought on with higher lactate concentrations actually aid the muscles in fighting fatigue, as chloride ions are retained better and action potentials can be maintained when the cell is functioning at a high rate.  In the absence of lactate it has been observed that the action potentials are inhibited faster, and this is directly related to muscle fatigue and performance.  

The point-counter point argument has been explored further in other articles as well.  A study found in the American Physiological Society determined that the cause of muscle fatigue during high-intensity exercises was not actually lactic acid buildup, but rather a buildup of phosphate ions due to the breakdown of creatine phosphates.  During high-intensity exercises our bodies rely on anaerobic sources of energy, so increased lactate levels should be irrelevant to the function and fatigue of muscle cells.  This falls in line with the claim made in the point-counterpoint article, and further goes to show why lactic acid buildup does not affect the function or fatigue of muscular tissues. 

Works Cited

Westerblad, Håken, et al. “Muscle Fatigue: Lactic Acid or Inorganic Phosphate the Major Cause?” Physiology, American Physiological Society, 1 Feb. 2002, www.physiology.org/doi/full/10.1152/physiologyonline.2002.17.1.17.

My favorite athletic accomplishment came recently this past fall.  I had joined the rugby team here at Union, and I was able to step up and be a core contributor to the team after playing for a year at Fordham University.  In our first match at Vassar, I carried the ball into contact and was brought down after a gain of a few yards.  When I stood up I felt my quad screaming in pain, but I was still able to stand and run effectively enough.  I managed to block out the pain in my leg enough to finish playing the rest of the game.  After the match was over, however, I had to be assisted to walk over to the bus, and was unable to walk when I got back to school.  I had a difficult time for the next few weeks, but I was able to play in our next match since we got a two week break.  By the end of the season my quad had completely healed, but I found out that I had torn my quad during my initial injury.  I was surprised that I had been able to play the rest of the game, and realized that the reason I was able to was probably due to the adrenaline during the game.  While I didn’t do anything that scored points, I felt that this was an impressive display of my body’s resiliency, and it was something that I never really thought my body was capable of until then.

I have always been interested in the way the human body works.  It’s one of the reasons that has driven me towards my interest in orthopedics and becoming a doctor.  I was unable to major in Bioengineering here as a transfer, so I enjoy taking classes that have a focus in the subject.  Exercise physiology interests me, because I feel like I will gain a better understanding of the way in which the human body works and handles physical strain.  I am hoping to learn more about joint and overall body health as a result of exercise, and how it plays a role in the long-term life of our bodies.  I also am hoping to learn about the biological and biochemical processes that occur in order for our bodies to function as they do.

I plan on using my background in Biochemistry to help me to understand the mechanisms that occur for our bodies to function effectively.  I have some basic knowledge of action potentials and the chemical processes that allow us to move.  I also have an in-depth understanding of the hormone pathways involved in regulating steroid hormones, and I believe that will give me a good base from which to discuss steroid usage in sports.  I am hoping to connect my Biochemistry major to allow myself and others to understand how the body works most effectively on a molecular level.