VCE Physical Education key terms

Voluntary, striated tissue attached to bones by tendons that contracts to produce movement and maintain posture. It works in opposing pairs across joints, so one muscle shortens while its partner lengthens.

The muscle that produces the desired movement by contracting and shortening, acting as the prime mover at a joint. It is assisted by synergists and opposed by the antagonist.

The muscle that opposes the agonist at a joint, lengthening under control to allow smooth movement and protect the joint from excessive force. It also helps return the limb to its starting position.

A contraction in which muscle tension stays roughly constant while the muscle changes length, producing joint movement. It may be concentric, where the muscle shortens, or eccentric, where it lengthens.

A contraction in which the muscle develops tension but does not change length, so no joint movement occurs. Examples include holding a plank or pushing against an immovable object.

A type of isotonic contraction in which the muscle shortens while generating force, such as the quadriceps lifting the body during the upward phase of a squat.

A type of isotonic contraction in which the muscle lengthens while still producing force, controlling movement such as lowering into a squat. It can generate high force and often causes muscle soreness.

Distinct kinds of muscle fibres differing in contraction speed and fatigue resistance. Slow-twitch fibres suit endurance, while fast-twitch fibres produce powerful, quick contractions but tire more rapidly.

A muscle fibre rich in mitochondria and capillaries that contracts slowly and resists fatigue well. It suits sustained aerobic activity such as distance running or cycling.

A muscle fibre that contracts rapidly and powerfully but fatigues quickly, relying mainly on anaerobic energy. It suits sprinting, jumping and other short, explosive efforts.

A single motor neuron together with all the muscle fibres it stimulates. Recruiting more motor units, or larger ones, increases the force a muscle can produce.

A rigid structure that rotates about a pivot when force is applied. In the body, bones act as levers, joints as pivots and muscles supply the effort force.

The pivot point about which a lever rotates. In the body it is the joint, and its position relative to the effort and load determines the lever class and mechanical advantage.

The perpendicular distance from the axis of rotation to the line of action of a force. A longer moment arm for the muscle increases the torque it can produce.

The ratio of the effort arm to the resistance arm of a lever. A ratio greater than one means a smaller effort can move a larger load, favouring force over speed.

An object remains at rest or in uniform motion unless acted on by an unbalanced external force. In sport, this explains why a moving ball continues until gravity, friction or a player alters it.

The tendency of an object to resist changes to its state of motion, determined by its mass. A heavier object needs a larger force to start, stop or redirect it.

A push or pull that can change an object's motion, shape or direction, measured in newtons. It has magnitude and direction, making it a vector quantity.

The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass. It is summarised as force equals mass times acceleration.

For every action force there is an equal and opposite reaction force acting on a different object. This explains how a swimmer pushes water backwards to move forwards.

A quantity described by both magnitude and direction, such as velocity, acceleration or force. Vectors are added tip to tail to find a resultant.

A quantity described by magnitude alone, without direction, such as speed, distance, mass or time. It contrasts with vectors, which require a direction to be fully described.

The single force equivalent to all forces acting on an object combined. If it is zero the object is in equilibrium; if not, the object accelerates in its direction.

The curved path followed by an object launched into the air and acted on only by gravity and air resistance. Horizontal and vertical components are analysed separately.

The angle between a projectile's launch direction and the horizontal. It strongly influences range; for many projectiles an angle near 45 degrees maximises horizontal distance.

Adenosine triphosphate, the energy currency of cells. Breaking its terminal phosphate bond releases energy for muscle contraction, and it must be continually resupplied.

An immediate anaerobic energy system using stored ATP and phosphocreatine to fuel very short, explosive efforts of roughly ten seconds. It needs no oxygen and fatigues quickly.

A fast energy pathway that breaks down glucose without oxygen to produce ATP, with lactate as a by-product. It dominates during high-intensity efforts lasting from about ten seconds to two minutes.

The energy system that uses oxygen to break down carbohydrate and fat, producing large amounts of ATP slowly. It dominates during sustained, lower-intensity activity and recovers the body after exercise.

A by-product formed when glucose is broken down without oxygen. It can be used as fuel by other muscles, and its accumulation is linked to fatigue in intense efforts.

The exercise intensity at which blood lactate begins to rise faster than it can be cleared. Training at this threshold improves endurance by delaying its onset.

The rate at which the body consumes oxygen, reflecting aerobic energy production. It rises at the start of exercise and plateaus when supply meets demand.

A period during submaximal exercise when oxygen uptake matches demand and heart rate, breathing and lactate remain relatively stable.

Immediate, short-term changes occurring during or just after exercise, such as increased heart rate, breathing rate, blood flow and body temperature. They return to resting levels during recovery.

Long-term physiological changes produced by repeated training, such as a larger heart, greater blood volume and more mitochondria. They improve performance and are lost if training stops.

The number of times the heart beats per minute, used to gauge exercise intensity. It rises during activity and is influenced by fitness, temperature and emotional state.

The volume of blood ejected by the heart with each beat. It increases with exercise and with endurance training, allowing the heart to work more efficiently.

The volume of blood pumped by the heart each minute, calculated as heart rate multiplied by stroke volume. It rises during exercise to deliver more oxygen to working muscles.

The maximum rate at which a person can take up and use oxygen during intense exercise, expressed in millilitres per kilogram per minute. It is a key indicator of aerobic fitness.

Standardised procedures used to measure components of fitness, such as the beep test for aerobic capacity. Results are valid only when protocols and conditions are controlled.

The extent to which a test measures what it claims to measure. A valid fitness test must genuinely assess the targeted component rather than a related but different quality.

The consistency of a test in producing similar results under repeated, identical conditions. Reliable testing requires standardised protocols, equipment and instructions.

Guidelines used to design effective programs, including frequency, intensity, time, type, overload, progression, specificity, reversibility and individuality. Applying them ensures training is safe and effective.

Systematically increasing training demands over time so the body is stressed beyond its current capacity, prompting adaptation. Increases should be gradual to avoid injury and overtraining.

The principle that training adaptations are specific to the type of activity performed. A program should mimic the movements, energy systems and intensities of the target activity.

Planned rest and low-intensity activity that allows the body to repair tissue and restore energy stores between training sessions. Inadequate recovery reduces performance and raises injury risk.