Comprehensive Notes on Fatigue and Skeletal System Responses

Fatigue

Decrements in muscular performance during continued effort, often accompanied by sensations of tiredness.

Power Output

The inability to maintain the required power output to continue muscular work at a given intensity.

Muscle Fiber Type

Different types of muscle fibers (e.g., Type 1, Type 2) respond differently to fatigue depending on their metabolic processes.

Phosphocreatine Depletion

Rapid energy source that is swiftly depleted during high-intensity activities, providing energy for about 10-15 seconds.

Glycogen Depletion

Limited reserves of glycogen in muscles and liver that can become depleted quickly during prolonged exercise.

Central Nervous System (CNS) Fatigue

Fatigue signals originating in the brain that may reduce motor output during muscular activity.

Peripheral Nervous System (PNS) Fatigue

Fatigue occurring at the neuromuscular junction due to altered neurotransmitter dynamics.

Bone Remodeling

A continuous cycle of bone resorption and formation, recycling about 5-7% of bone mass weekly.

Wolff’s Law

The principle stating that bone adapts to the stresses placed upon it, leading to increased bone mineral density under load.

Mechanotransduction

The process by which bone responds to mechanical loading, resulting in adaptations and increased bone mineral density.

Ergogenic Effects of Caffeine

Caffeine can improve muscle contraction and central nervous system functions, enhancing performance when taken in appropriate doses.

Central Fatigue

Signal related to muscle performance that originates in the brain, leading to reduced motor output.

Peripheral Fatigue

Occurs at the neuromuscular junction due to altered neurotransmitter dynamics affecting calcium release.

Energy Systems and ATP Generation

Fatigue results from energy systems being unable to generate sufficient ATP during exercise.

Heat Accumulation

Increase in core temperature during exercise that stresses the body and can impair muscle function.

pH and Muscle Function

Lower pH caused by H+ ions during intense activities impedes enzyme function and slows metabolism.

Fluid Movement in Bone

Triggers of exercise-induced adaptations in bone density are related to fluid movement within the bone structure.

Bone Adaptation Mechanism

Processes by which bones remodel in response to mechanical loading to ensure strength and density.

Skeletal System Function

Supports movement, protects vital organs, stores calcium, and facilitates the production of blood cells.

Role of Vitamin D in Bones

Enhances intestinal absorption of calcium, playing a crucial role in bone mineralization and health.

Resistance Training and Bone Density

Regular resistance exercise can lead to increased bone density and strength in response to mechanical load