Chronic adaptations to training (Topic 14)

Vocabulary flashcards covering key chronic adaptations to training across cardiovascular, respiratory and muscular systems.

Chronic adaptations to training

Long-term physiological changes that develop with regular training (usually 6+ weeks) in the cardiovascular, respiratory and muscular systems, improving performance.

Training effect

The combined result of all chronic adaptations leading to improved performance.

SAID principle

Specific Adaptation to Imposed Demands; adaptations are specific to the type of training performed.

Reversibility (detraining)

The loss of chronic adaptations when regular training stops.

VO2 max

The maximum rate at which the body can consume, transport and use oxygen during maximal exercise.

Relative VO2 max

VO2 max expressed per kilogram of body weight (ml/kg/min).

Absolute VO2 max

VO2 max expressed as total oxygen consumption (L/min or mL/s) without body weight adjustment.

Lactate inflection point (LIP)

The highest exercise intensity at which lactate production and clearance are balanced; beyond this, lactate accumulates.

a-VO2 diff

Arteriovenous oxygen difference; the difference in oxygen content between arterial and venous blood.

Capillarisation

Increase in capillary density around muscles or heart tissue due to training.

Capillary density

Number of capillaries surrounding each muscle fibre; increases with endurance training.

Cardiac hypertrophy

Enlargement of the heart muscle, especially the left ventricle, from sustained aerobic training.

Left ventricle size/volume

Increase in LV cavity size/volume contributing to higher stroke volume.

Stroke volume (SV)

Volume of blood ejected from the left ventricle per beat; increases with training.

Cardiac output (Q)

The total volume of blood pumped by the heart per minute (Q = HR × SV).

Resting heart rate (RHR)

Heart rate at rest; typically decreases with aerobic training.

Recovery heart rate

How quickly heart rate returns to resting after exercise; faster in trained individuals.

Blood volume

Total amount of blood; increases with aerobic training, including plasma volume and red blood cells.

Plasma volume

Fluid portion of blood; increases with training, aiding circulation and temperature regulation.

Hemoglobin

Oxygen-carrying protein in red blood cells; increases with training to improve oxygen transport.

Pulmonary ventilation

Movement of air into and out of the lungs per minute (VE = RF × TV).

Tidal volume (TV)

Air inspired or expired per breath; increases with aerobic training.

Respiratory frequency (RF)

Breaths per minute; tends to decrease at rest/submax with training but can rise at maximal effort.

Pulmonary diffusion

Movement of O2 and CO2 between alveoli and capillaries; increases with training.

Mitochondria

Cell organelles where aerobic energy (ATP) is produced; increase in number/size with training.

Myoglobin

Oxygen-binding protein in muscles that delivers O2 to mitochondria; increases with training.

Oxidative enzymes

Enzymes that drive aerobic metabolism; increase with aerobic training.

Fuel stores

Muscle glycogen and triglyceride stores increase with endurance training.

Glycogen sparing

Greater use of fats for energy to preserve glycogen during exercise.

Fuel utilisation (fat vs carbohydrate)

Training increases fat oxidation and reduces reliance on glycogen at given intensities.

Aerobic capillarisation of skeletal muscle

Increased capillary networks around muscle fibres, improving O2 delivery.

Mitochondrial density

Increase in number of mitochondria in muscle cells, enhancing aerobic energy production.

Myoglobin stores

Increased myoglobin in muscle to improve oxygen transport to mitochondria.

Glycogen stores

Increased intramuscular glycogen available for ATP production.

Glycolytic enzymes

Enzymes of anaerobic glycolysis; can increase with anaerobic training but may rise with mixed programs.

Type 1 fibre adaptations

Slow-twitch fibres may increase in size or oxidative capacity with endurance training.

Type 2A fibre adaptations

Fast-twitch oxidative fibres may gain oxidative characteristics with endurance training.

Muscular hypertrophy

Increase in muscle fibre size and cross-sectional area due to resistance/strength training.

ATP–CP system (PC stores)

Stored ATP and creatine phosphate; stores increase with anaerobic training to support rapid energy.

ATPase and creatine kinase

Enzymes increasing breakdown/resynthesis of ATP/CP for rapid energy release.

Glycogen synthase

Enzyme increasing glycogen synthesis; helps store glycogen in muscles.

Glycolytic capacity

The muscle’s capacity to generate energy through glycolysis; increases with anaerobic training.

Motor unit recruitment

Ability to recruit more motor units to produce greater force.

Rate coding

Firing rate of motor units; increases with resistance training to boost force production.

Inhibitory signals

Neural reflexes (e.g., Golgi tendon organs) that limit force; training can reduce these signals.

Neuromuscular adaptations to resistance training

Changes in neural control, coordination and firing that enhance strength and power.

Neural drive

Combined effect of motor unit recruitment and rate coding during contraction.

Fibre hyperplasia

Increase in the number of muscle fibres (less common; still debated).

Muscular fibre type adaptations

Endurance training can shift some Type 2 fibres toward more oxidative properties.

Aerobic vs anaerobic training

Aerobic improves oxygen delivery/use; anaerobic increases muscle size and explosive capacity.

Lactate tolerance

Enhanced ability to buffer and tolerate lactate/H+ during high-intensity effort.

Motor unit synchronisation

Simultaneous firing of multiple motor units to produce smoother, stronger contractions.

Synonymous terms: hypertrophy vs hyperplasia

Hypertrophy: increase in fibre size; Hyperplasia: potential increase in fibre number (less clear in humans).

ECONOMY of movement

Efficiency with which the body uses oxygen to generate ATP at a given pace or intensity.