This chapter focuses on developing speed, change-of-direction, and agility. These terms are often used interchangeably, but they describe different physical capacities and skills because they place different biomechanical and cognitive demands on the athlete. They’re defined as follows:
Speed: The skills and abilities needed to achieve high movement velocities.
Change of direction: The skills and abilities required to explosively change movement direction, velocities, or modes.
Agility: The skills and abilities needed to change direction, velocity, or mode in response to a stimulus.
In most sports, the ability to outrun opponents is a major performance advantage. Just as important is the ability to rapidly change direction during play - whether to evade an opponent, create space, or gain a tactical advantage.
Even when an action looks like “speed,” the underlying qualities can differ. Performance may depend on acceleration, maximal velocity, and technical execution. For example:
Linear speed is typically expressed in sprinting.
Multidirectional speed appears in open-field play and involves changes in direction.
Generating high speeds matters in both track and field and team sports. However, track performance depends heavily on linear speed, while success in multidirectional sports often depends on changing direction quickly and efficiently in response to constantly changing situations.
Change-of-direction abilities require deceleration and reacceleration, usually in a pre-planned pattern.
Agility adds a perceptual-cognitive element, requiring athletes to change direction in response to an external stimulus (e.g., an opponent’s movement).
Acceleration is involved in both change-of-direction and agility, but each has unique technical and cognitive demands.
Key point: Speed requires the ability to accelerate and reach maximal velocity, whereas agility performance relies more heavily on perceptual-cognitive skills and decision-making.
| Training Group | Force at 300ms | Rate of Force Development (RFD) | Impulse Area |
| Untrained | Low | Low | Small |
| Heavy resistance-trained | Moderate | Moderate | Medium |
| Explosive-ballistic-trained | High | High | Large |
The Spring-Mass Model (SMM) is a mathematical framework that describes sprinting as a coordinated sequence of spring-like actions. During sprinting:
The leg acts like a spring that compresses at foot strike and extends during push-off, propelling the athlete forward.
The center of mass lowers during midstance, aligning with maximum spring compression.
The model shows how elastic energy is stored and released during running, highlighting the role of muscle stiffness and tendon compliance.
Elite sprinters often produce more vertical force during the first half of ground contact.
As stride frequency increases, muscle stiffness becomes a key feature of effective sprinting.
Change-of-direction and agility require more than physical output. They also depend on neuromuscular and perceptual-cognitive factors, including:
Eccentric strength, especially for braking and reorienting the body.
Short ground contact times (e.g., 0.23-0.25 sec for agility vs. 0.09-0.11 sec for sprinting).
Stretch-shortening cycle (SSC) involvement during rapid reacceleration.
Perceptual-cognitive skills (e.g., decision-making, anticipation) to efficiently process tactical information.
Running speed = stride length × stride frequency
Key takeaways:
Sprinting involves repeated stride cycles: support (stance) + flight phases.
Speed increases by improving:
Stride length (more ground covered per stride)
Stride frequency (faster turnover)
Elite sprinters:
Stride length ~2.70 m
Stride rate ~4.63 steps/sec
Novice sprinters:
Stride length ~2.56 m
Stride rate ~4.43 steps/sec
The interaction between stride length and frequency across various speeds.

Stride length comparison (elite vs. novice)

Stride rate comparison (elite vs. novice)

Sprinting consists of:
Acceleration phase
Maximum velocity phase
Coaches should emphasize:
Proper ground force application
Efficient transition between eccentric braking and concentric propulsion
Reduced ground contact times during acceleration
Start:
Athlete should distribute balanced body weight using a set position (blocks, 3- or 4-point staggered start).
Front lower leg angle: ~90°
Rear lower leg angle: ~133°
Legs generate ~905 N of force during start clearance (~0.28 s).
Vertical velocity is highest during block clearance and the initial steps to elevate the center of gravity.
Key cues:
Exit angle of front leg during block clearance: ~160°
First step touchdown: ~0.5 m from start line
Initial velocity: up to 5 m/s
Acceleration:
Recovery leg should stay low; toes barely leave the ground.
Elite stride rate: 5.26 steps/sec; novice: 3.45 steps/sec
Elite stride length (first two steps): 1.13-1.15 m; novice: 1.21-1.50 m
Shorter stride = more frequent ground contact = better horizontal velocity
Ground time: elite ~0.123 s vs. novice ~0.223 s
By 20 m: sprinter should be nearly upright, with the head rising at the same rate as the torso.
Maximum velocity:
Body alignment: shoulders stacked over hips over feet
Relaxed head/shoulders, eyes forward
Elite top speed: ~12.55 m/s vs. novice: ~11.25 m/s
Elite stride rate: 4.63 steps/sec; novice: 4.43 steps/sec
Elite ground contact time: 0.087 s vs. novice: 0.101 s
Early:
Midflight:
Late:
Early:
Continued concentric hip extension
Eccentric knee flexion + plantarflexion = shock absorption
Late:
| Error | Cause | Coaching Recommendation |
| Hips too high at start | Misunderstanding crouch | Adjust foot spacing and lower into start position |
| Stepping out laterally | Improper force direction | Cue pushing through the ground |
| Short/tight arm motion | Misunderstanding swing | Teach elbow drive and trunk rotation |
| Neck tension | Misunderstanding head posture | Cue head in line with spine |
| Premature upright posture | Weak push-off or bad posture | Cue trunk alignment and drive through the ground |
| Overstriding | Misunderstanding force application | Teach “run in their lane” and reduce ground contact |
| Cycling leg action | Improper force | Emphasize vertical force; reduce open gap during stance |
| Transverse arm errors | Fatigue or habit | Cue sagittal plane swing and proper alignment |
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