1. Speed, Agility, and Speed-Endurance Development
NSCA Chapter 20 Page 471

2. Speed, Stride Frequency, and Stride Length
The ability to move the body in one intended direction as fast as possible
Product of stride length and stride frequency (rate)
Stride Frequency (rate)
Number of strides taken in a given amount of time (or distance)
It may be improved with core strength, plyometric training, and technique
Stride Length
The distance covered in one stride, during running
High correlation to leg length (2.1 to 2.5 times leg length)

3. Agility
The ability to start (accelerate), stop (decelerate and stabilize), and change direction quickly, while maintaining proper posture
Requires high levels of neuromuscular efficiency
Individual is constantly regaining a center of gravity over his or her base of support, while changing directions, at various speeds

4. Quickness Reaction time
The ability to react and change body position with maximum rate of force production, in all planes of motion, from all body positions, during functional activities
Ability to react to visual, auditory, and kinesthetic feedback

5. Physiological Factors of Speed and Agility
Genetic Factors
Muscle fiber type
Body Fat
Height
Age
Gender
Anaerobic or Speed Endurance (ability to use fuel)

6. Muscle Fiber Type
There are three types of muscle fibers found in various parts of every athletes body:
Slow-Twitch Red (type I)
Fast-Twitch Red (type IIa)
Fast-Twitch White (type IIb)

7. Slow-Twitch Red (Type I) Muscle Fibers
Relies on oxygen to produce energy (aerobic)
Develops force slowly
Fatigue resistant (high endurance)
Low power output
High aerobic capacity for energy supply
Endurance athletes have 70-80% Type I fibers

8. Fast-Twitch Red (Type IIa) Muscle Fibers
This intermediate fiber type can contribute to both anaerobic and aerobic activity
Develops force relatively quickly
Elite sprinters have 70-80% Type II fibers
Moderate:
Fatigability
Power output
Aerobic and anaerobic power

9. Fast-Twitch White (Type IIb) Muscle Fibers
This fiber type does not rely on oxygen to produce energy (anaerobic)
Develops force rapidly
High fatigability (low endurance)
Low aerobic power
High anaerobic power

10. Muscle Fibers
The two fiber types generally produce the same amount of force per contraction, but fast twitch fibers produce that force at a higher rate (they fire more rapidly).
Muscles with a high percentage of fast-twitch fibers exert quicker, more powerful contractions
Individuals born with a high percentage of fast-twitch fiber have a higher speed potential than those born with slow-twitch fibers

11. Muscle Fibers People who are not athletes have 50% Type I and II
The right kind of high-intensity training (heavy load) will recruit and train fast-twitch fibers and aid in the improvement of acceleration and speed
Olympic lifts
Heavy medicine ball

12. Muscle Fibers
Postural muscles such as the soleus are composed mostly of slow-twitch fibers whereas the quadriceps contain a mixture of both fibers, which permit jogging and sprinting
The theory that slow-twitch fibers can be changed into fast-twitch fibers is controversial
New evidence suggests that prolonged high-intensity training may produce that effect and improve the ratio of fast-twitch to slow-twitch fibers

13. Body Fat
Body fat <6% for men
Body fat of <15% for women
The lower ranges may by unhealthy, depending on the individual
On the other hand, excess fat negatively affects both acceleration and speed

14. Age
No physiological reason exists for speed to diminish significantly from age unless the athlete ceases training, loses strength and power, or adds body fat

15. Gender
World records by men in the 100 meters are .75 seconds faster than those by women
The faster stride rates and longer strides of males appear to account for the time differences
Hormonal and anatomical differences have implications for acceleration and speed

16. Proper Running Mechanics
Foot/Ankle Complex:
Pointing straight ahead in a dorsiflexed position when it hits ground
Excessive flattening or external rotation of foot creates stress and decreases overall performance
Knee Complex:
Knees straight ahead
Excessive adduction or internal rotation of the femur leads to overuse injuries

17. Proper Running Mechanics
Lumbo-Pelvic-Hip Complex (core)
The body should have a slight lean during accleration
The spine should be fairly neutral without excessive extension or flexion
Head
In line with the lumbo-pelvic-hip-complex

18. Proper Sprint Mechanics
Triple Flexion on the Front of the Leg
Ankle dorsiflexion
Knee flexion
Hip flexion
Keeping the lumbar spine neutral
Triple Extension on the Back of the Leg
Ankle plantarflexion
Knee extension
Hip extension

19. Training Stride Length
Resisted Sprinting
Examples
Running uphill or upstairs
Running with a parachute, harness, or sled

20. Training Stride Frequency (Rate)
Over-speed training
Running at speeds higher than the individual is used to
Examples:
Running down hill
High speed treadmills
Tubing

21. Explosive Power (Plyometrics)
Mechanics of Speed
Other factors in determining speed:
Strength
Explosive Power (Plyometrics)
Flexibility
Muscle Imbalance

22. Mechanics of Speed Muscle Balance:
Prime movers in sprinting are the knee extensors, hip extensors, and ankle plantar flexors
An imbalance usually exists between the knee extensors/flexors
The strength of the hamstring muscle group is a sprinter’s weakest link
It should be improved to 70 to 90 percent of the strength of the quadriceps group
A minimum ratio of 70 percent is recommended for the prevention of injury

23. Speed Training Program Design
Frequency:
number of speed training sessions per week, depends on individuals goals
Recovery:
1:5 to 1:10 between repetitions
Volume:
distance covered during a training session (50 meters to 100 meters)
Progression: principles of progression

24. Speed Training Program Design
Stabilization
4-6 speed ladder drills
1-2 cone drills
Strength
6-9 speed ladder drills
Power
2-4 cone drills

25. Speed and Cone Drills

26. Speed Endurance
The metabolic conditioning needed to support speed/agility movements over an extended period of time (six or more seconds)
Athletes with poor speed endurance are unable to accelerate and sprint repeatedly because of fatigue
Offensive lineman vs. receiver
Slowing occurs because of lactic-acid buildup
Improved lactic-acid tolerance, increased quick energy stores, and improvement in the rate that quick energy is available are related to anaerobic fitness, age and nutrition.