ACTN3 Essay

Muscles are made up of small fibres that contract making the whole muscle contract. There are three types of muscle fibre; Type 1, Type 2a and Type 2b. All individuals have a combination of all fibre types and their combination of fibre types is genetically determined. Different parts of the body have different combinations of fibre types.

Based on Dr. Noakes’ alternative paradigm, VO2 plateau is not reached and oxygen delivery is not the limiting factor for VO2 max, but muscle factors are. He believes the muscle factors that limit performance are myosin ATPase activity due to the myosin cross-bridge cycling rate and calcium sensitivity of skeletal muscle (Bassett & Edward, 1997). From my understanding, sprinters have percentage of type II fibers which allows for faster cross-bridge cycling rates that allows them

Spectators at sporting events come to watch athletes compete at their best during a game or meet. However, there is more to sports than just “playing the game”, “running the course”, “performing”, or whatever the case may be. Athletes understand how important sport specific workouts are; cross country is one sport that focuses on this. Most people think that “all you do is run”, although running is indeed the task, it takes a combinations of different workouts to build up an athlete’s body in order to be race ready. It is beneficial for cross country runners to do workouts that focus on speed, strength, and endurance.

Physical activity is a key component in maintaining ones individual health and promoting longevity in life. In order for individuals to initially commence and continue being physically active, we are required to look at their motivation and attitude towards physical activity, as this plays a crucial role. A number of genes have been identified as affecting an individual’s level of physical activity. One of these genes is the ACTN3 gene, and is said to be the most highly researched sporting performance gene (Sessa et al., 2011). However the association between the ACTN3 gene and an individual’s motivation and attitude towards physical activity is poorly researched and inadequately understood.

One type of workout runners complete consists of several short intervals that include 100, 200, 300, and 400 meter intervals. “The purpose of short interval workouts is to increase raw speed, stride power and running economy. They are beneficial even for marathon runners, whose race pace is substantially slower than the speeds that can be sustained over such short distances” (Fitzgerald 1). In order for athletes to win races, they must have a swift sprint at the end of a race, and practicing short intervals improves an athletes fast twitch muscles. Middle-distance intervals are another type of workout that every running athlete should complete and has different benefits than short-interval workouts. The main benefits are the, “the resulting increase in aerobic capacity, lactate recycling capacity and fatigue resistance will enable [athletes] to sustain faster speeds for longer periods of time” (Fitzgerald 2). When all the athletes on the Calabasas High cross-country team complete middle-distance intervals, they gain endurance and it shows on future races. Without these workouts, the runners tire out quicker and do not improve five kilometer times. For athletes who run extremely long races such as 10Ks or half-marathons, prolonged intervals are pivotal for achievement. Long intervals benefit athletes because, “this pace is close to lactate threshold pace for many runners

More hemoglobin allows the muscles to work harder for a longer period of time. The higher aerobic capacity, gives men the advantage over women when running events over 800 meters.

The differing results are likely because of differences in skill level among test subjects, methods of evaluation, and erratic sprint distances. The main strength qualities being explored in this data analysis are: absolute strength, relative strength, high-load speed strength, and low-load speed strength. Every sport requires several combinations of these strength qualities to be successful (13). Absolute strength is the measurement of how much force a subject can exert with no regard to body size (3). Relative strength is the measurement of strength to body size. High-load speed strength is the ability for the muscle to exert a high amount of force while contracting at a high speed. The tests to gauge high-load speed strength are typically short in nature, executed at maximal speeds, and produce high power outputs, and include exercises such as the power clean, snatch, and push jerk (1). Triple extension of the hips, knees, and ankles during these movements allows the athletes to express force against the ground rapidly. Low-load speed strength involves low velocity movements, and is a quality that “reflects the dynamic abilities necessary for sport. They are the maximal strength tests of choice for strength and conditioning professionals”

In an attempt to understand the underlying biological differences of these runners Pui W. Kong hypothesized that one variation is, “related to the fact that Kenyans generally live and train at high altitude (around 2000 m above sea level) influencing their oxygen capacity” (Kong, 2008). One study that addressed this compared Kenyan runners oxygen uptake, as well as blood ammonia

There are three types of myosin fibers within a muscle and those are aerobic fiber 1a (slow-twitch), aerobic fiber 2a (fast-twitch), and anaerobic fiber 2x (fast-twitch). 1a is low intensity and it increases in intensity to 2x. 1a and 2a are aerobic, so they require oxygen for cell respiration to complete glycolysis, Kreb’s cycle, and the electron transport train. If they do not get enough oxygen, they start to create lactic acid because they can only complete glycolysis. Whereas 2x fibers immediately start to create lactic acid because they are anaerobic and can not use oxygen so they only do glycolysis. Everyone is born with these three types of fibers usually almost equally balanced throughout their muscles but some people will get an unequal

twitch muscles. Fast twitch muscles have a fast form of myosin ATP and are very

The age-related loss of muscle power is more rapid than the parallel loss of muscle strength which in turn is more rapid than the loss of muscle mass. Patients with sarcopenia manifested a reduction in the number of both type I/slow-twitch

In fact, there is a high probability that there isn’t one at all (4). More than likely, there is a group of genes that interact with each other in just the right way to produce a high-level unique athlete (4).

Also black people have low body fat that also can be helpful for them in running. According to Sailor article “Muscle and tendon physiology also contribute to black “athleticism.” It is well publicized that blacks have a higher percentage of fast twitch muscle fibers and higher levels of glycotic and phosphogenic enzyme activity levels, when diet and activity levels are controlled for, which would provide an advantage in explosive, short-duration muscular exertions.“ Black people have short bellies as well; this is a great help for them for running. Since the muscles can be stretched and store energy that can be this energy can be retransferred during running that will cause them lose less energy. These are some physiological reasons that black people can do better in sports. Due to these biological advances they got with time, because of their genetic material that has been changed in evolution, they can do better in sport competitions in specific fields of sport compare to other races. However they do poor in some other sports such as swimming because of these differences as

Several gaps in the current body of knowledge have been indentified including, among others: small sample size of most athletic cohorts, lack of corroboration with replication cohorts of different ethnic backgrounds (particularly, made up of non-Caucasian athletes), the need of research accounting for the potential role of epigenetics in elite athletic performance, and also the need for future models that take into account the association between athletic status and complex gene gene and gene environment

Think of your national athletics team at the Olympics. All the individuals in it are exceptionally talented – but at different things. The javelin thrower is able to throw his javelin powerfully and release it from his grasp at exactly the right time; the marathon runner has phenomenal endurance; and the sprinter has powerful leg muscles so that she can explode out of the starting blocks.