Question: What makes up a sprinter or gives one the ability to perform explosively??
Looking at sprinting, it is dependent on high velocity limb movement and the biggest component for this to happen is based on the muscle physiology of the individual. A sprinter legs have muscle fibers that contract and relax faster over a short period of time producing maximum force, will determine a winner. There are other factors that contribute this like the individuals muscle adaptation to training and the ability of the muscle to meet the demands of high velocity performance.
Let us go deeper into the muscle physiology. Force production in our muscles is due to the interaction of protein filaments that make-up a myofibril (actin and myosin), in our muscles the myosin filament is made up of three different muscle fiber types. There is type I, IIa, IIb and IIx that have different characteristics and predominance in athletes. Type I, is the slow twitch fiber and it is common in long distance runners and also present in everyone; there is also type IIb which is a fast twitch fiber which produces the maximum force production and contraction velocity in the body and it is not so common in the average person but prevalent in sprinters; then there is type IIa which is also a fast twitch fiber but lies in between type I and IIb in force production and contraction velocity, it is present in most individuals since it has aerobic and anaerobic characteristics.
Muscle fiber types are predetermined by genetics, so it is either you are born a sprinter or you are not but studies have shown that type IIx to be a `default’ fiber in humans where activity is absent but has abilities to be converted either to type IIa or type IIb. This is a slight change of about 2%-10% and is based on the training one does, and after the training stops the muscle fiber goes back to its normal state in about a month or more.
| Type I fibers | Type II a fibers | Type II x fibers | Type II b fibers |
Contraction time | Slow | Moderately Fast | Fast | Very fast |
Size of motor neuron | Small | Medium | Large | Very large |
Resistance to fatigue | High | Fairly high | Intermediate | Low |
Activity Used for | Aerobic | Long-term anaerobic | Short-term anaerobic | Short-term anaerobic |
Maximum duration of use | Hours | <30 minutes | <5 minutes | <1 minute |
Power produced | Low | Medium | High | Very high |
Mitochondrial density | High | High | Medium | Low |
Capillary density | High | Intermediate | Low | Low |
Oxidative capacity | High | High | Intermediate | Low |
Glycolytic capacity | Low | High | High | High |
Major storage fuel | | | Creatine phosphate, glycogen | Creatine phosphate, glycogen |
Myosin heavy chain,
human genes | | | | |
Khay Zondo
Question: Does clothing or the latest shoes help you physiologically perform faster or better??