Speed development during puberty
This is an excerpt from Conditioning Young Athletes by Tudor Bompa & Michael Carrera.
Speed-Training Model for Athletic Formation
Speed development increases during puberty. Most children - both boys and girls - experience an acceleration in speed development during this stage. Such improvement may relate to increases in body and muscle size.
Strength gains positively influence speed development. From puberty on, the testosterone level in boys starts to increase dramatically, as does the ability to increase strength. The direct result of strength gains is improvement in both running speed and movement time.
Although boys show clear improvements from the later stages of pubescence, girls seem to plateau in their rate of speed development. Some speed gains can result from improved nervous system coordination of the muscles involved in quick actions, but most are the consequence of strength development and the ability of the muscles to contract more powerfully. As a result, the arms can drive more forcefully and the legs can push against the ground with more power.
Gains in upper-body power, especially the arms, improve movement time, reflecting the ability to throw the ball farther or bat more powerfully. On the other hand, improved leg strength translates into kicking the ball with more power. For most team sports in which running speed is important, the ability to quickly change directions is also significant. This skill is the result of improved nervous system coordination and strength gains of the muscles involved.
Scope of Speed Training
To improve speed to higher levels, speed training during puberty has to be specific. However, it should still be a part of multilateral athletic development, and children should do it in connection with developing other abilities.
During puberty, quickness and acceleration training lead to better nervous system adaptation, which results in enhanced coordination of the muscles performing the arm and leg actions. As strength starts to improve, especially for boys, movement time improves, which influences upper-body quickness and running speed. Similarly, as leg strength improves, children start to push more forcefully against the ground and are able to drive their bodies forward much faster.
Although coed speed training may occur during prepubescence, we advise that you separate the sexes starting at pubescence. Boys become stronger from puberty on, which positively influences the rate of limb movement and speed. As a result of these differences, it is better for girls and boys to train in separate groups.
Teaching Correct Running Technique
To improve running efficiency, athletes should work on running form. A crucial component in achieving running efficiency is good arm drive. The arms are driven back, forward, and up to the face level. Leg frequency increases as the rate of arm drive increases because the rate of leg movement is led and coordinated by arm drive and frequency. The thigh of the driving leg (for our example, this is the right leg) should reach a horizontal line; from this point on the foot of the same leg is projected forward and down. The back of the foot lands on the ground through a brushing action. As the body moves forward, the other (left) leg is driven forward. The right leg is now pushing against the ground, projecting the body forward. These actions are repeated for as long as the sprints last.
As children perform these exercises, the coach or teacher should constantly observe them for good form - keeping the shoulders down and relaxed, driving the arms simultaneously, and bringing the knees high. The position of the body should be vertical, and the eyes should be focused ahead. The foot should strike the ground quickly, coming underneath the body as it moves forward. The running step has the following phases:
- The propulsion phase, in which the foot pushes against the ground with power to drive the body quickly forward.
- The drive phase, in which the opposite leg drives forward with the thigh horizontal. The opposite arm also drives along the body, with the hand at shoulder height (arms are bent 90 degrees). It is essential to keep the ankle locked until the landing phase.
- The landing phase, in which the foot strikes the ground and quickly comes underneath the body.
- The recovery phase, in which the heel of the propelling leg quickly drives toward the buttock while the opposite arm quickly moves forward.
As children approach postpubescence, they can increase the total amount of speed training. Whether using play, games, relays, or even sprinting routines, they can progressively increase the distance run with high velocity from 20 to 50 or 60 meters or yards.
Speed training can be fun for children and instructors alike. Children can perform a variety of exercises involving play, games, and especially relays. Instructors can organize relays in ways that use many exercises, such as sprints, sprints with turns, runs around cones with direction changes, carrying or throwing medicine balls, or jumps over safe equipment at a low height.
Instructors should also organize special exercises that improve reaction time. The objective is to decrease the time it takes for the child to move a limb - for instance, the arms and legs in running or the arms in throwing a ball. Such a goal can be achieved in two simple phases:
- During the early part of improving movement time, the instructor positions herself in front of the children, facing them. At her signal - visual (clap) or sound (whistle) - the children perform the task. Because children can see the instructor, they can start the action faster.
- As children improve their reaction time, after a few months or one to two years, the instructor selects a position behind the children so she can see the children but they cannot see her. Now the children will rely on sound only. The purpose of this exercise is the same: At the signal the children perform the task as quickly as possible.
Parallel with speed and movement time exercises, children should participate in simple exercises for power improvement. For the upper body, they can use a variety of medicine ball throws. Tennis and baseball throws for distance, alternating the arms for balanced development, are fun and beneficial for developing power in the upper body. Children can develop leg power by performing simple jumps on, off, and over low and safe equipment. (Refer to chapter 7.)
As postpubescence approaches, children can progressively increase to the maximum intensity (speed) and power of exercises to improve neuromuscular coordination. As children show better adaptation to training they can also increase the number of repetitions, depending on their work tolerance.
A critical element in speed training is the duration of the rest interval between repetitions. Because the ability to repeat high-quality exercises depends on the freshness of the neuromuscular system, the rest interval between repetitions must be as long as necessary to almost fully recover and restore the fuel needed to produce energy.
As table 5.3 illustrates, instructors can use relays for developing speed in pubescent children, and these relays can be of longer distance than those used for prepubertal children: 10 to 30 meters or yards, repeated four to six times, with a rest interval of two or three minutes. Children can repeat speed training in a straight line of 20 to 50 meters or yards five to eight times with a longer rest interval (four or five minutes) between each repetition. During the rest, the children should stretch the muscles for better relaxation. For team sports, children can perform speed training with changes of direction, turns, and stop and go for 5 to 25 meters or yards, repeated 5 to 10 times, with a rest of two or three minutes. Performing game-specific skills fast also develops specific speed.
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