PE - Chronic adaptations

Aerobic Respiratory Adaptations - Tidal Volume

• Adaptation: Increases (more air breathed in and out per breath).

• Benefit: More oxygen is available in the lungs to be transported to working muscles for aerobic energy.

Aerobic Respiratory Adaptations - Pulmonary Diffusion

• Adaptation: Increases due to more surface area in the alveoli and more capillaries.

• Benefit: More oxygen moves faster from the lungs into the blood.

Aerobic Respiratory Adaptations - Ventilation

• Adaptation: Decreases at rest/submax (more efficient), but increases at maximal intensity.

• Benefit: Allows for maximum oxygen intake when working at your hardest.

Aerobic Cardiovascular Adaptations - Cardiac Hypertrophy (Aerobic)

• Adaptation: Increase in the size and volume of the left ventricle.

• Benefit: The heart can hold and pump more blood per beat.

Aerobic Cardiovascular Adaptations - Stroke Volume (SV)

• Adaptation: Increases at rest, submax, and maximal intensities.

• Benefit: More oxygenated blood and fuels are delivered to muscles every single beat

Aerobic Cardiovascular Adaptations - Resting Heart Rate

• Adaptation: Decreases (bradycardia).

• Benefit: The heart is more efficient; it pumps the same amount of blood with fewer contractions.

Aerobic Cardiovascular Adaptations - Capillarisation

• Adaptation: Increased density of capillaries in the heart and skeletal muscles.

• Benefit: Improved delivery of oxygen/nutrients and faster removal of waste products

Aerobic Cardiovascular Adaptations - Blood Volume & Haemoglobin

• Adaptation: Total blood volume and red blood cells increase.

• Benefit: More haemoglobin to carry oxygen and better temperature regulation.

Aerobic Muscular Adaptations - Mitochondria

• Adaptation: Increased size and number (density).

• Benefit: More sites available to produce aerobic energy (ATP).

Aerobic Muscular Adaptations - Myoglobin

• Adaptation: Increased levels in the muscle cells.

• Benefit: Faster transport of oxygen from the blood to the mitochondria for energy.

Aerobic Muscular Adaptations - a-vO2 Difference -blood

• Adaptation: Increases (more oxygen is "extracted" from the blood).

• Benefit: More oxygen is used by the muscles, reducing reliance on anaerobic systems.

Aerobic Muscular Adaptations - Fuel Stores & Oxidative Enzymes

• Adaptation: Increased storage of glycogen and fats (triglycerides), plus more enzymes to break them down.

• Benefit: Muscles can produce more energy faster and for longer durations.

Aerobic Muscular Adaptations - Glycogen Sparing

• Adaptation: Improved ability to metabolise fats at higher intensities.

• Benefit: Saves (spares) glycogen stores for the end of a race, delaying fatigue.

Glycogen sparing - where the body uses fats for energy more efficiently. This spares glycogen stores for later, allowing an athlete to work at higher intensities for longer before fatigue sets in.

Anaerobic & Resistance Adaptations - Cardiac Hypertrophy (Anaerobic)

• Adaptation: Thickening of the left ventricle wall.

• Benefit: Allows for a more forceful contraction to eject blood.

Anaerobic & Resistance Adaptations - Muscle Hypertrophy

• Adaptation: Increased size of fast-twitch fibers and more myofibrils/contractile proteins.

• Benefit: Increased speed and force of muscular contractions.

Anaerobic & Resistance Adaptations - Anaerobic Fuel Stores & Enzymes

• Adaptation: Increased ATP, PC, and Glycogen stores, plus more ATPase, Creatine Kinase and glycolytic enzymes.

• Benefit: Faster rate and higher yield of energy for explosive movements.

Anaerobic & Resistance Adaptations - Motor Unit Recruitment

• Adaptation: Increased ability to recruit more and larger motor units.

• Benefit: Greater force production for powerful movements.

Anaerobic & Resistance Adaptations - Synchronisation & Firing Rate

• Adaptation: More motor units fire at the same time and at a faster frequency.

• Benefit: Reaches maximal force faster (explosive power).

Key Performance Concepts - VO2 Max

• Definition: The maximum oxygen the body can take up and use.

• Benefit: Allows you to work at higher intensities for longer using aerobic energy.

Key Performance Concepts - LIP (Lactate Inflection Point)

• Definition: The highest intensity where lactate production equals removal.

• Training: 80–85% Max HR.

• Benefit: You can run/cycle at a faster pace before lactate begins to accumulate uncontrollably.

Key Performance Concepts - Lactate Tolerance

• Definition: The ability to keep working while lactate and H+ ions build up.

• Training: Above 85% Max HR (Intermediate Interval).

• Benefit: Improved buffering capacity allows you to sustain high-intensity efforts despite the "burn".

Chronic adaptations timeline

at least 6–8 weeks with a minimum of 3 sessions per week to develop. If training stops, the body will gradually return to its pre-training state.

Chronic adaptation definition

A long-term physiological response of the body’s cardiovascular, respiratory, and muscular systems that develops over time as a result of regular training