It's important to consider what kinds of muscle fibers your body is mainly made up of so you can learn the exercises and activities your body will benefit from most.
After talking about the difference muscle fiber types in my exercise physiology class, Type I, Type IIa and Type IIx, I began to think more about my own muscle fiber types and which may be more dominate in my body. I am an 800m runner, so my training consists of both longer runs and quick interval training as well. 800m runners have an increase in both Type I and Type II muscle fibers, which is essential for success in the mid distance events. Since an 800m race is only two laps long, it is essential to build up speed through Type II muscle fibers to finish the race strong. It is also important to have some endurance as well, since the race cannot be executed in a full out sprint. This is where the Type I muscle fibers are important.
As mentioned above, its important to be aware of your specific percentage of each muscle fiber type so you can workout accordingly. Knowing if one has 40 percent Type I and 60 percent Type II, or 90 percent Type I and 10 percent Type II could be very useful information when trynig to find a training program that will work for an individual. Training should reflect the individuals physiology, as opposed to training for a specific race.
When considering long distance runners vs sprinters, those with more endurance and a passion for long distance running will likely have a majority of Type I fibers. This also means they have a slower contraction speed due to less ATPase splitting, which allows for slower turnover. Type I muscle fibers are also predominately aerobic, which also means they have an increase in mitochondria density for and increased ATP energy production to sustain their energy throughout the race for a longer period of time. Contrarily, those with more Type IIa and Type IIx muscle fibers will have more anaerobic fitness. This includes a faster ATPase turnover so more ATP can constantly be made for more cross bridges to form for increased force and power.
As a 800m runner, I fall somewhere in the middle of both extremes. I have always preferred speed workouts to long runs, but I enjoy the endurance training involved for the 800m race as well. I never considered why speed training and endurance training were both used as a training program for the 800m. Understanding what makes up the different muscle fiber types and what makes each so important has not only helped me to understand the physiology of muscle, but how I can apply it to my own workouts and training regime. It could be very useful to know my exact muscle fiber build up, so I can train accordingly focused on my own muscle physiology. Although this can be measured using a muscle biopsy, it is a process most people are not comfortable going through. It would be very interesting researching other ways muscle fiber could be measured without taking a piece of muscle directly from the body. Being aware of each individuals' muscle fiber percentage could impact the sport of Track and Field immensely. If athletes were to detect their muscle fiber build up, they could begin their track career accordingly, based off which event would benefit their muscle fiber build up.
I’m very grateful for the knowledge I have acquired as an exercise science major so I am able to apply the physiology to my own athletic life. I have a new awareness about my body and why it works the way it does, which has become almost essential in improving my athletic performance.
