CHAPTER 19 - Program Design and Technique for Speed

Question 1

RFD (Rate of Force Development)

Answer 1

the development of maximal force in minimal time, typically used as an index of explosive strength

change in force by chance in time

Question 2

Impulse

Answer 2

the product of the generated force and the time required for its production.

measure under the force-time curve

change in momentum

Question 3

speed

Answer 3

rate at which an object covers a distance

Question 4

Velocity

Answer 4

how fast and which direction an object is traveling

Question 5

Acceleration

Answer 5

rate in which the velocity changes in time

Question 6

Most Important Factor Of Sprinting Success

Answer 6

RFD

Question 7

Nervous System

Answer 7

Strength training enhances neural drive

Question 8

Increases in Neural Drive

Answer 8

related to increases in both muscular force production and the rate of force production

Question 9

SSC (Stretch-Shortening Cycle)

Answer 9

Eccentric-Concentric coupling phenomenon

Question 10

Criteria to improve SSC

Answer 10

1. Skillful, multijoint movements
2. Brief work bouts (Plyo + Heavy Resistance)

Question 11

Spring-Mass Model

Answer 11

Mathematical model that depicts sprinting’s a type of human locomotion in which displacement of a body mass is the aftereffect from energy produced and is delivered through the collective coiling and extension of spring-like actions

Question 12

Running Speed

Answer 12

Sprint speed is an interaction of stride frequency and stride length

Question 13

Differences between elite and novice sprinters

Answer 13

1. Amount of vertical force applied to the ground during the stance phase
2. Greater forces must be applied in shortest time (RDF)
3. Elite sprinters achieve longer stride lengths compared to novice
4. Elite sprinters achieve higher stride rates

Question 14

Increase in Speed

Answer 14

It can be achieved by increase of stride length or stride frequency, or both.

Question 15

Ground Contact Time

Answer 15

The total time allotted for a single stance phase

Question 16

Step Length

Answer 16

Distance between the toe and heel of two consecutive footsteps.

Example: cm between the heel of right foot and the heel of left.

Question 17

Stride Length

Answer 17

Distance between the heel in two consecutive steps of the same foot.

Example: meters between the heel of the right foot and the heel of the next ground contact made by the right foot.

Question 18

Flight time

Answer 18

Duration of time that an athlete is not in contact with the ground.

Question 19

Stride angle

Answer 19

The angle at which the foot leaves the track

Question 20

Monitoring Speed Development

Answer 20

1. Ground Conctact Time
2. Step Length
3. Stride Length
4. Stride angle
5. Flight time
6. Speed
7. Acceleration

Question 21

How long does it take for maximal contraction force to occur?

Answer 21

300ms

Question 22

What should be emphasized when prescribing exercises to improve speed ability?

Answer 22

Increase in neural drive
Overload muscles in hips/knees with SSC

Question 23

Braking Impulse

Answer 23

braking forces over certain periods of time - related to acceleration

Question 24

Stance Phase

Answer 24

Eccentric braking period
Concentric propulsive period

Question 25

Flight Phase

Answer 25

Recovery
Ground Preparation

Question 26

START

Answer 26

Front leg: 90 degrees / Rear leg : 133degrees

Vertical velocity is greatest during block clearance and the subsequent two steps due to the need for appropriate rise in the body’s COG

Exit angle: 160degrees
Optimal length of touchdown of first step is 0.5m
Initial Velocity: 5m/s

Question 27

ACCELERATION

Answer 27

Stride length is shorter in elite sprinters due to the need for less flight time so that horizontal velocity is increased through more frequent ground contact time during ACC

By ~20m, the bodys has been raised nearly upright. head is relaxed, neutral position, rising at the same rate as the torso

Question 28

MAXIMUM VELOCITY

Answer 28

Shoulders appearing to sit directly above the hips, which sit above the foot during stance phase

Head relaxed, neutral position with the eyes focused ahead
Shoulders stay down and relaxed, leg and arms cycle together

~12.55m/s elite / 11.25m/s novice

top sprinters display higher stride at maximum velocity

Question 29

Early Flight

Answer 29

Eccentric Hip Flexion: decelerates the backward rotation of the thigh

Eccentric Knee Extension: decelerates backward rotation of lef/foot

Question 30

Midflight

Answer 30

Concentric hip flexion: accelerates thigh forward

Eccentric knee extension —> eccentric knee flexion

Question 31

Late Flight

Answer 31

Concentric hip extension: rotates thigh backward in preparation for foot contact

Eccentric knee flexion: accelerates leg backward, limiting knee extesnion; stops before foot strike

Question 32

Late Flight

Answer 32

Concentric hip extension: rotates thigh backward in preparation for foot contact

Eccentric knee flexion: accelerates leg backward, limiting knee extension; stops before foot strikes

Question 33

Early Support

Answer 33

Continued Concentric Hip Extension: minimize the braking effect of foot strike

Brief concentric knee flexion followed by eccentric hip extension: resists the tendency of hip/ankle extension to a hyperextended knee
Eccentric plantarflexion: help absorb shock

Question 34

Late Support

Answer 34

Eccentric hip flexion: decelerates backward thigh rotation; rotates trunk in preparation for forward takeoff
Concentric knee extension: propels COG forward
Concentric plantarflexion: aids in propulsion

Question 35

Improve in COD and Agility

Answer 35

COD: ground contact time and ground reaction force during plant phase
Agility: perceptual-cognitive factors

Eccentric strength and maximal strength alongside the concentric explosiveness during reacceleration

Question 36

Guidelines Coaching COD/Agility

Answer 36

Visual Focus
Body position during braking ad reacceleration
Leg Action
Arm action

Question 37

Monitoring Agility Development

Answer 37

1. Changed of direction deficit
   Ground Contact time
   Exit velocity
   Entry velocity
   Decision making time