1. Anatomy and Functional Kinesiology

This is the "map" of the human body. Exercise professionals must understand not just where muscles are, but how they create movement across joints.

• Musculoskeletal System: Identifying bones, joints (synovial, hinge, ball-and-socket), and muscle groups.
• The Kinetic Chain: How the nervous, muscular, and skeletal systems work together to produce movement.
• Planes of Motion: Analyzing movement in the Sagittal (forward/back), Frontal (side-to-side), and Transverse (rotational) planes.

2. Exercise Physiology

This is the study of how the body’s systems (cardiovascular, respiratory, and endocrine) respond to the "stress" of exercise.

• Bioenergetics: How the body converts food into adenosine triphosphate (ATP) via aerobic and anaerobic pathways.
• Acute vs. Chronic Adaptations: * Acute: Immediate changes like increased heart rate and heavy breathing.
• Chronic: Long-term changes like muscular hypertrophy (growth), increased bone density, and improved $VO_2$ max.
• General Adaptation Syndrome (GAS): The three-stage response to stress: Alarm (initial fatigue), Resistance (adaptation/building), and Exhaustion (overtraining).

3. Biomechanics

Biomechanics applies the laws of physics to human movement. It is essential for correcting form and preventing injury.

• Levers: Understanding how the body uses bones as levers and joints as fulcrums to move loads.
• Force and Torque: Calculating how much stress is placed on a joint during a specific lift (e.g., why a long-limbed person might struggle with a specific squat depth).
• Newton’s Laws: Applying concepts like inertia, acceleration, and action-reaction to athletic movements like sprinting or jumping.

4. Motor Behavior

This field focuses on how the brain and nervous system control movement and how skills are learned.

• Motor Learning: The process of improving the smoothness and accuracy of movements through practice.
• Motor Control: How the central nervous system integrates sensory information to produce a motor response.
• Proprioception: The body's ability to sense its position in space, which is critical for balance and coordination.