What is exercise physiology?

Exercise Physiology

Study of skeletal muscle contractions and their effects.

Physical Activity

Movement by skeletal muscles leading to energy expenditure.

Exercise

Structured physical activity.

Types of Muscle

Skeletal, smooth, and cardiac.

Skeletal Muscle

Makes up 40-50% of body weight; characterized by long, multinucleated fibers, striated appearance, and voluntary control.

Epimysium

The outer layer of connective tissue surrounding a muscle.

Perimysium

Connective tissue that surrounds fascicles within muscles.

Endomysium

The connective tissue that surrounds individual muscle fibers.

Sarcolemma

The membrane that encloses muscle fibers.

Myofibrils

Contain actin and myosin, essential for muscle contraction.

T-tubules

Conduct impulses into the muscle fiber, triggering calcium release.

Sarcoplasmic Reticulum (SR)

Calcium storage organelle within muscle fibers.

Mitochondria

Organelles responsible for aerobic metabolism.

Sliding Filament Theory

Describes how actin slides over myosin, shortening sarcomeres during contraction.

Neuromuscular Junction

Site where acetylcholine (ACh) triggers muscle action potential.

Type I Muscle Fiber

Slow-twitch fibers characterized by small diameter, high oxidative capacity, and resistance to fatigue, mainly used in endurance activities.

Type II Muscle Fiber

Fast-twitch fibers characterized by large diameter, high peak force, and quick fatigue, used for sprints and high-power activities.

Eccentric Exercise

Type of exercise that causes Delayed Onset Muscle Soreness (DOMS), leading to symptoms appearing 1-3 days post-exercise.

Length-Tension Relationship

Describes the optimal length of muscle for maximum force production.

Force-Velocity Relationship

As velocity of contraction increases, the force produced by the muscle decreases.