High intensity

Three main functions of the skeletal system

1. Support: Provides a rigid structural framework for the body.

2. Protection: Safeguards vital internal organs.

3. Movement: Works alongside muscles and joints to facilitate locomotion.

Four bone classifications and anatomical examples

1. Long bone: Femur

2. Short bone: Carpals

3. Flat bone: Scapula

4. Irregular bone: Vertebrae

Major bones of the upper and lower limbs

• Upper limb: Humerus, radius, and ulna

• Lower limb: Femur, tibia, and fibula

Joint (skeletal system)

A point where two or more bones meet; it acts as a mechanical lever system permitting bones to bend, rotate, or pivot for movement.

Hinge joint vs. Ball-and-socket joint

• Hinge joint: Uniaxial joint permitting movement in one plane (e.g., knee and elbow; bicep curls or kicking a football).

• Ball-and-socket joint: Multiaxial joint permitting movement across all planes with wide range of motion (e.g., shoulder and hip; front crawl swim strokes or throwing a javelin).

Cranium

The protective flat/irregular bone structure of the skull that encloses and safeguards the brain.

Three muscle tissue types

1. Skeletal muscle: Striated, voluntary muscle attached to the skeleton.

2. Cardiac muscle: Striated, involuntary muscle making up the heart walls.

3. Smooth muscle: Non-striated, involuntary muscle found in hollow internal organs and blood vessels.

Voluntary vs. Involuntary muscles

• Voluntary muscles: Controlled consciously via somatic neural commands (e.g., biceps brachii).

• Involuntary muscles: Function automatically without conscious oversight (e.g., cardiac muscle, smooth muscle of the intestines).

Major muscles of the upper and lower body

• Upper body: Biceps, triceps, and deltoids

• Lower body: Quadriceps, hamstrings, and gastrocnemius

Agonist and antagonist roles during a bicep curl

• Agonist (prime mover): Biceps brachii (contracts concentrically to flex the elbow joint)

• Antagonist: Triceps brachii (relaxes and lengthens to allow flexion to occur)

Three primary functions of skeletal muscle tissue

1. Produces gross and fine movement by exerting tensile forces on bones.

2. Maintains posture and bodily alignment against gravity.

3. Generates metabolic heat through involuntary and voluntary contractions.

Concentric vs. Eccentric muscle contractions

• Concentric: The muscle shortens while developing tension against a resistance (e.g., upward curling phase of a bicep curl).

• Eccentric: The muscle lengthens while maintaining tension to decelerate a load (e.g., controlled lowering phase of a bicep curl).

Isometric contraction

A muscular contraction where force is exerted without any change in overall muscle length or joint angle (e.g., maintaining a plank or static wall sit).

Fast-twitch vs. Slow-twitch muscle fibres

• Fast-twitch (Type II): Rapid contraction speed, high force output, anaerobic reliance, and rapid rate of fatigue.

• Slow-twitch (Type I): Slower contraction speed, moderate force output, high aerobic capacity, and high resistance to fatigue.

Dominant fibre type for a 100 m sprint

Fast-twitch muscle fibres, because they rapidly generate maximal force, explosive power, and velocity needed over short durations.

Three primary functions of the cardiovascular system

1. Oxygen and nutrient transport: Delivers oxygen, glucose, and essential metabolites to active tissues.

2. Waste removal: Transports metabolic by-products and carbon dioxide to excretory organs.

3. Protection and thermoregulation: Distributes heat throughout the body and seals vascular damage via clotting mechanisms.

Blood vessel types: Arteries, capillaries, and veins

• Arteries: Thick, muscular, and elastic walls; carry oxygenated blood away from the heart under high hydrostatic pressure.

• Capillaries: Microscopic single-cell walls; enable diffusion of gases, nutrients, and waste.

• Veins: Thinner walls containing internal one-way valves; return deoxygenated blood toward the heart under low pressure.

Acute cardiovascular responses to exercise

• Heart Rate (HR): Increases frequency of beats to accelerate blood delivery.

• Stroke Volume (SV): Increases the volume of blood ejected per beat due to enhanced myocardial contractility.

• Cardiac Output ($Q$): Rises dramatically, calculated as $Q = \text{HR} \times \text{SV}$.

Left ventricle

The thick-walled muscular chamber of the heart that pumps oxygenated blood at high pressure into the aorta for systemic circulation.

Anatomical airflow pathway to the bloodstream

$$\text{Nasal Cavity / Mouth} \rightarrow \text{Pharynx} \rightarrow \text{Larynx} \rightarrow \text{Trachea} \rightarrow \text{Bronchi} \rightarrow \text{Bronchioles} \rightarrow \text{Alveoli} \rightarrow \text{Bloodstream}$$

Biomechanical mechanisms of inhalation vs. exhalation

• Inhalation: Diaphragm contracts and flattens; external intercostals elevate the ribs; thoracic volume increases, internal pressure drops below atmospheric pressure, drawing air in.
• Exhalation: Diaphragm relaxes and ascends; intercostals allow ribcage to depress; thoracic volume drops, internal pressure rises, pushing air out.

Gaseous exchange at the alveoli

Oxygen diffuses down its partial pressure gradient from the alveoli across the semi-permeable alveolar-capillary membrane into deoxygenated blood; simultaneously, carbon dioxide diffuses from the capillary blood into the alveoli to be exhaled.

Three primary metabolic energy systems

1. ATP-PC System: Anaerobic; utilizes stored phosphocreatine for immediate maximal power ($0\text{--}10\,\text{s}$).
2. Lactic Acid (Anaerobic Glycolysis) System: Anaerobic; breaks down glycogen rapidly without oxygen, producing lactate and hydrogen ions ($10\text{--}90\,\text{s}$).
3. Aerobic System: Oxidative; uses oxygen in the mitochondria to fully metabolize carbohydrates and fats for prolonged activity.

Dominant energy system: 100 m sprint vs. Marathon

• 100 m sprint: ATP-PC system (provides immediate, explosive energy without delay).

• Marathon: Aerobic energy system (provides steady, sustainable ATP replenishment via glycogen and lipid oxidation).

Aerobic respiration vs. Anaerobic respiration

• Aerobic respiration: Occurs in the presence of oxygen, breaks down substrate completely into $CO_2$ and $H_2O$, produces high ATP yields, and produces no fatiguing acidic by-products.

• Anaerobic respiration: Operates without oxygen, breaks down fuel rapidly to supply high-intensity work, and produces lactic acid and hydrogen ions that impair muscle contraction.

Five anatomical movement definitions

• Flexion: Decreasing the joint angle between articulating bones.

• Extension: Increasing the joint angle between articulating bones.

• Abduction: Moving a limb laterally away from the sagittal midline.

• Adduction: Bringing a limb medially toward the sagittal midline.

• Rotation: Pivoting a bone along its longitudinal axis.

FITT principle acronym

• F (Frequency): Number of training sessions conducted per given timeframe.

• I (Intensity): Magnitude of effort or resistance exerted.

• T (Time): Length or duration of the session or working interval.

• T (Type): Specific training method or modality chosen.

Progressive overload

The planned, gradual increase in physical stress placed upon the body (by altering FITT factors) to ensure continued neuromuscular and metabolic adaptations without stagnation.

Training principles: Specificity, Reversibility, and Individuality

• Specificity: Tailoring training to match the exact physiological, biomechanical, and energetic demands of the sport.

• Reversibility: The loss of accrued fitness adaptations when regular training stimulus is reduced or ceased ("use it or lose it").

• Individuality: Recognizing that each athlete adapts uniquely to identical training stimuli due to genetics, training history, age, and recovery capacity.

Continuous, Interval, and Fartlek training methods

• Continuous training: Steady-state, non-stop exercise sustained for an extended duration without rest periods.

• Interval training: Structured work periods alternated with predetermined recovery periods.

• Fartlek training: Continuous exercise integrating variable speeds, intensities, and terrain changes ("speed play").

Circuit training

A training format involving a sequence of varied exercise stations executed in order with short, scheduled recovery breaks between exercises; allows simultaneous development of aerobic fitness, muscular endurance, and strength.

Metafit training characteristics and physiological benefits

• Format: A 30-minute bodyweight-only High-Intensity Interval Training (HIIT) modality.

• Benefits: Stimulates excess post-exercise oxygen consumption (EPOC / calorie afterburn), improves both aerobic and anaerobic systems, and requires zero specialized equipment.

Exercise progression vs. Exercise regression

• Progression: Modifying an exercise movement to increase biomechanical complexity, resistance, or neuromuscular demand.

• Regression: Simplifying an exercise to reduce intensity, load, or technical demand to match current skill or mitigate fatigue.