Speed can be defined as a rate of motion. During physical activity speed can either refer to that rate of motion on the body or of a body part from point A to point B.
Speed is demonstrated well in athletic sprint events, where runners look to cover the given distance as quick as possible. Runners first look to accelerate from a stationary position to a anticipated speed that is as sustainable as possible for a given event. In the case of a 100m sprint, maximal speed would be desired.
Speed is related very closely to muscular power, which refers to an individual’s ability to exert force rapidly. High levels of muscular power enable athletes to accelerate to and obtain high rates of speed.
Factors effecting Speed
The factors effecting Speed can be very similar to those of muscular power and muscular strength including cross sectional area, muscle fibre type, age and gender.
During a high intensity speed activity, the anaerobic capacity of an individual can determine an individual’s ability to rapidly provide ATP to the working muscles and prevent or delay associated fatigue during the event. As ATP levels in the muscles decline, the decrease will be reflected in the ability to maintain speed.
The recruitment of motor units can also play a role in determining speed. Increased speed and frequency of impulses can lead to faster contraction time, along with the preferential recruitment of fast twitch muscle fibres, to provide an increase in speed.
(Malpeli, Telford, Whittle, Corrie, 2010)
TESTING SPEED
As speed can either be referred to as whole body speed or part body speed, although in fitness testing whole body speed is usually the focus and looks at the time it takes to cover a given distance.
50-meter sprint test and 20 meter sprint test:
Aim: To cover the distance as quick as possible.
Procedure: A warm up should be completed by the subject prior to the test. The test can be completed with either a stop watch or electronic timing gates. Using electronic gate subjects are to begin stationary just behind the gate. They may begin running when they are ready, and will trigger the timer as they activate the first gate. This method will eliminate the element of reaction time. Subjects are then to complete the full distance as quickly as possible and time is to be recorded.
Appropriate distance for the test should be determined to match common patterns during competition. AFL players for example use a 20-meter sprint test as it is thought to be the most specific distance to the sport.