Understanding Muscle Strength, Speed, and Flexibility

Muscle tension results from the contraction of muscle fibers. In the muscular system:

• Muscle fiber types: fast or slow, length, and thickness.
• Volume of fibers (muscle hypertrophy).
• Types of muscle contraction: concentric, isometric, and isotonic.

In the nervous system:

• Coordination of different muscles for movement: agonists, antagonists, and fixers.

Other factors:

• Muscle temperature, which can increase with a good warm-up.
• Training, form, or motivation.

Sorting: Force = Mass x Acceleration

Maximum Force:

The capacity to create maximum tension during muscle contraction. It is related to muscle mass or load.

Maximum Acceleration:

Minimal or no load, for example, when a weightlifter lifts weights in competition.

Explosive Strength:

The ability to overcome very high loads with maximum speed of movement. Mass or load: small to medium. Acceleration: Maximum, for example, an athlete performing a long jump.

Force-Resistance:

The ability to exert force during prolonged activity and resist fatigue. Load: medium. Acceleration: medium, for example, rowers in a kayak competition.

Speed:

The ability to perform one or more movements in the minimum possible time.

Classification:

Reaction Rate:

The time elapsed from the appearance of a stimulus until the muscle contraction: simple and discriminative reaction time.

Contractile Speed

Displacement Speeds

Flexibility:

Maximum capacity of extension in a given joint movement.

Factors:

Mechanical:

• Type of joint.
• Musculoligamentous flexibility.

Emotional:

• Temperature.
• Age.
• Social customs.

Absolute, work, and residual flexibility.

Training Principles:

Phase of Reaction or Alarm:

Stimulation alters and causes a loss of homeostatic equilibrium.

Phase of Resistance:

The organism struggles to reestablish initial equilibrium against the stimulus.

Phase of Depletion:

The stimulus disappears or exceeds the organism's limits.

Principle of Individuality:

Training programs should be adapted to each athlete's individual needs, initial capacities, and the specificity of the sport practiced.

Principle of Adaptation

The human body can adapt to the effects of training (fatigue) and, after a rest period, can increase its level of performance.

Principle of Progression:

A slow but steady increase in workload (training load) is the only way to produce adaptations and increase performance.

Principle of Continuity:

Systematic physical activity allows for adaptations. If training is not maintained, positive effects will not be achieved.

Principle of Alternation:

Rest periods are necessary to produce overcompensation.

Principle of Variation:

Training programs should use a variety of training systems and content to avoid boredom and monotony.