Anatomy

Discover what abduction is in bodybuilding, this movement which moves a limb away from the central axis of the body to develop the stabilizing muscles.

Adduction is a movement that brings a body part toward the body's midline. Opposite of abduction.

BMI (Body Mass Index) is a quick health screening tool, but it doesn't account for body composition. Limited but useful.

Body fat percentage measures the share of fat in your total body mass. A key indicator of body composition.

Extension is the anatomical movement that increases the angle between two body segments. Opposite of flexion.

Fat mass is the total weight of fat tissue. Essential for survival, but excess harms health and aesthetics.

Muscle fibers are the cells that make up muscle. Two main types — Type I (slow) and Type II (fast) — define your physical potential.

Flexion is the anatomical movement that decreases the angle between two body segments. Opposite of extension.

Lean mass is everything in your body except fat: muscles, bones, organs, water. A real performance indicator.

Muscle mass is the total weight of muscles in the body. Key indicator of strength, metabolism, and longevity.

Range of motion (ROM) is the amplitude through which a joint or muscle can move during an exercise. Crucial for hypertrophy and joint health.

The sarcomere is the basic contractile unit of muscle. Composed of actin and myosin, it produces all your movements.

Type I fibers (slow-twitch) are endurance-oriented muscle fibers. Resistant to fatigue, they sustain prolonged efforts.

Type II fibers (fast-twitch) are powerful muscle fibers optimized for explosive efforts. Essential for strength and power.