By: Juan Rodriguez
Did you ever wonder why some people can last a long time while exercising? Or why high intensity exercisers have the power they need for their challenging exercises? Our body is composed of a variety muscle fibers that work differently based on the activity that is being performed.
Slow Twitch Muscle Fibers
Lets start with the slow twitch muscle fibers, also known as slow oxidative (SO) muscle fibers or type 1 muscle fibers. These fibers are highly used for endurance exercises and may provide up to hours of energy . Something to keep in mind is that these muscle fibers contact very slowly and cannot generate energy for fast performance. This means exercises that are mainly long in duration or high repetition in low weight-bearing exercises. Now you may wonder how people that run long periods of time are able to maintain that energy needed to keep going? Our bodies are composed of cells called Mitochondria that produce the energy needed by breaking down sugar, fat and other chemicals with the assistance of oxygen. The more an endurance athlete trains, the more Mitochondria they have and therefore, they may exercise for a longer time.
Fast Twitch Muscle Fibers
Fast twitch muscle fibers on the other hand are larger and more powerful muscles that work for less amount of time. These muscle fibers work primarily with creatine and sugar to produce the amount of energy needed for the exercise. Since these muscle fibers generate more power, they are found in individuals who perform high intensity and power exercises that require high amounts of energy and fast muscular contraction. Those activities may include sprinting, power lifting, and soccer for example. How long will the energy last with these muscle fibers? There are a few fast twitch muscle fibers that last different amounts of time, but depending on the amount of mitochondria (as mentioned above) each muscle fiber contains, the time may vary. However overall, the duration is about 30 seconds to 1 minute for a fast twitch muscle fiber. To sum it all up, if you are someone that performs more fast and high intensity power exercises, you will have a greater density of fast twitch muscle fibers. On the other hand, if you perform more endurance exercises, you will have a greater density of slow twitch muscle fibers and higher amounts of Mitochondria!
If you have any questions about this blog, feel free to comment below !
By: Juan Rodriguez
How does Creatine play a role in our energy system?
Creatine is a supplement taken by many exercisers that allows their bodies to perform better during a power exercise that lasts about 0-6 seconds. Our bodies first energy system is called the Phosphocreatine energy system (ATP-PC). In this system, Creatine allows for our muscles to quickly replenish the energy that is being used during the exercise. If we run out of Creatine at some point during our 6 second intervals, we turn to our next energy system called Glycolysis. The question is, what is the benefit of taking Creatine? Well, if we take about 25-30 second breaks between our interval training, our body will be able to restore the energy we spent during our 0-6 second bouts. This is good news for those power lifters or sprinters that perform quick and powerful activities. What happens if we exercise passed the 0-6 second mark? At that point, our body will stop utilizing Creatine as a form of creating energy and begin using another energy system called Glycolysis.
Why do we need Carbohydrates?
Carbohydrates play an essential role in our bodies when we are performing fast paced exercises that last roughly about 6 seconds to 2 minutes long. These Carbohydrates are broken down to glycogen (sugar) and are used as energy for the body. This process is called Glycolysis. During this process, glycogen (sugar) is then broken down to a more simpler form and as a byproduct, lactic acid accumulates in our muscles. If you don't already know, lactic acid build up is the feeling we get when we feel the "burn" during our exercise routine and causes our body to fatigue. So, how do we remove lactic acid? All in short, Lactic Acid is turned into energy and carbon dioxide through a system called the Cori Cycle. It is important and crucial that our bodies are supplied with Carbohydrates to ensure that we have the necessary energy that is needed for our exercise routine! when do we ever use fat as energy? Fat is another source of energy that requires a longer time to break down, which means that our demand for energy must slow down as well!
How does Fat play a role in our bodies?
Fat is another source of energy that requires a longer time to break down, which means that our demand for energy must slow down as well! Any exercise passed about the 2 minute mark requires the usage of oxygen and the breakdown of Fat. This form of energy is the least powerful of the three energy systems we use. This explains why this form of energy is used for a lot of endurance athletes. One thing to keep in mind is that we will always use a certain percentage of every source of energy. For example, if we were doing a long distance exercise our primary use of energy would be Fat, but we will also be utilizing a certain percentage of Carbohydrates at the same time!
If you have any questions or would like to learn more about this blog, feel free to comment below or email Ageless Fitness at firstname.lastname@example.org!
by: Juan Rodriguez
Why is exercise important for decreasing sugar levels?
Exercise plays a big role in decreasing sugar levels, thanks to our GLUT4 receptors. These GLUT4 receptors are activated through the contraction of muscles and allow for insulin to bind with these receptors and allow for the uptake of sugar (glucose) into the muscle. This sugar molecule is then used as energy for the body.
In other words, if we move around and stay active, we will be able to utilize sugar for energy!
Should we take insulin medication before or after exercise?
When taking insulin medications, people sometimes wonder if it is safe to take them before or after an exercise. The answer is mainly going to be after the exercise or a decreased dosage before the exercise bout. If you don't already know, insulin is used to regulate the blood sugar, and allows for our body to take in sugar to use it for energy (all in short). As I mentioned above, we have these GLUT4 transporters that will activate during exercise and allow for our bodies to naturally take in sugar without the help of insulin. The risk of taking insulin before an exercise could result in hypoglycemia, meaning that you will have low blood sugar levels.
All in short, insulin should be monitored closely when exercising to prevent hypoglycemia and to maintain normal blood sugar level during and after our exercise!
Should we be active before or after our meals?
There are many studies that talk about whether or not it is more beneficial to exercise before or after our meals. Although the answer is not set in stone, one thing is for certain, we will have energy to carry us through the exercise in a fasted and non-fasted state. When exercising on an empty stomach, our body will use our stored energy called glycogen as energy, as well as fat. There are studies that talk about how exercising at a fasted state will promote weight loss, since we are using more fat as energy in this state. On the other hand, exercising after a meal makes sense that you will have more energy to carry you through the exercise routine, but this is also not certain. There are some studies that found no difference in exercise performance during a fasted state or fed state.
So, where does this end? Although there are no certainties, depending on your exercise routine it is your personal preference on whether or not you would like to eat before an exercise or not, you will benefit from the exercise regardless.
Julie is the program director and head personal trainer at Ageless Fitness. She focuses on wellness and health education with her clients and encourages the process of creating programs to be individual and informative