Author: Owen Barder
Source: Running for Fitness Blog
Date: Dec 2013
This article explains how your body breaks down/burns energy for extended periods of strenuous exercise, like, in the case of the article the running a marathon.
Barder explains how, as we learned in class, our energy comes from three major macromolecules: carbohydrates, lipids, and sometimes proteins. Running, which is an aerobic activity, burns mostly carbohydrates and lipids. Low intensity running begins by burning mostly fat, but as the intensity goes up, so does the amount of carbohydrates burned. These two macromolecules do not store/burn energy in the same way though, which has led runners to develop strategy for storing and relaeasing energy in the most efficient way possible.
Throughout the post, Barder discusses tips and strategies like “carbo-loading" which is where runners eat a lot of carbohydrates the night before a marathon so their stores of carbohydrates. He also explains the importance long, slow training runs which teach the body to rely on lipids for a longer period time of exercise instead of glycogen (a carbohydrate), a more limited source. He also discusses how and when to get energy during long runs in the context of the carbohydrate capacity of the blood. By using Barder's scientific strategies, runners can perform their best.
Can running also burn proteins?
ReplyDeleteI agree with Catherine, but with slightly different reasoning. In average circumstances, the body will not break down protein for energy, since it has carbohydrates that can be burned first. It only breaks down fats (ketosis) when it's glucose stores start to dwindle. However, after running on glucose and fat for a while, the glucose store will finally run out. The body cannot get enough energy from only lipids, so it breaks down proteins, releasing amino acids into the bloodstream. These amino acids travel to the liver and are converted to glucose the body can use for energy. On a thirty minute run, you would be very unlikely to need to break down protein, unless you had been depriving your body of carbohydrates. Marathons runners though, can get to the point where all their glucose stores have been used up, and will begin to break down some proteins towards the end of the race.
DeleteNo, because in normal conditions, proteins participate in the generation of energy but they themselves are not actually energy. Therefore, they cannot really be burnt in the same way carbs and lipids can be.
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