2025 IB DP Sports, Exercise and Health Science Practice Paper with Answers

The initial rapid increase in heart rate up to approximately 100 beats per minute at the very beginning of exercise is primarily due to the withdrawal of parasympathetic (vagal) nerve activity. Beyond this threshold, further increases in heart rate are driven by the stimulation of the sympathetic nervous system and circulating catecholamines.

Award [1] for the correct option B.

Topspin causes the upper surface of the ball to rotate in the direction of the oncoming air flow, creating a region of high air pressure. The lower surface rotates in the opposite direction, creating a region of lower pressure. This pressure difference generates a downward force (negative lift), which causes the ball to dip more rapidly than it would under gravity alone.

Award [1] for the correct option C.

The feedback is delivered by an external agent (the coach), making it extrinsic (or augmented) feedback. Because the feedback details the movement mechanics and movement technique rather than the final score or outcome, it is categorized as Knowledge of Performance.

Award [1] for the correct option A.

During the downward phase of a squat, the knee joint flexes. To control the movement against gravity, the quadriceps femoris muscles must lengthen while generating force, which is an eccentric contraction. This acts as a braking mechanism to control the rate of descent.

Award [1] for the correct option D.

Consuming carbohydrates with a high glycemic index (GI) immediately after exercise (within 30 minutes) rapidly elevates blood glucose and insulin levels, optimizing the transport of glucose into muscles and speeding up glycogen resynthesis during the early recovery window.

Award [1] for the correct option A.

Hans Eysenck proposed that extroverts have lower baseline levels of cortical arousal in their Reticular Activating System (RAS) compared to introverts. Consequently, they seek out external stimulation, dynamic environments, and high-intensity social settings to reach their optimal levels of arousal.

Award [1] for the correct option B.

Autonomy refers to the need for individuals to experience self-direction, personal agency, and choice. Allowing an athlete to participate in designing their own training schedules directly promotes a sense of personal choice and volition (autonomy). In contrast, option C targets the need for relatedness, option D targets competence, and option B is an extrinsic reward.

Award [1] for the correct option A.

Somatic anxiety refers directly to the physical symptoms and physiological bodily changes associated with anxiety, including autonomic arousal (e.g., increased heart rate, sweating, dry mouth, tension). Cognitive anxiety is the mental component of anxiety, such as worry or negative self-talk.

Award [1] for the correct option C.

In untrained individuals, stroke volume typically increases during submaximal exercise until it plateaus at approximately 40% to 60% of \(VO_2\text{max}\). Beyond this intensity, any further increase in cardiac output is achieved primarily through an increase in heart rate. Systolic blood pressure increases while diastolic blood pressure remains relatively constant.

Award 1 mark for identifying that stroke volume plateaus at submaximal intensity while heart rate continues to increase linearly to exhaustion.

Newton's Third Law of Motion states that for every action, there is an equal and opposite reaction. When the sprinter exerts a force backward and downward onto the blocks (action), the blocks exert an equal and opposite force forward and upward onto the sprinter (reaction), propelling them forward.

Award 1 mark for identifying Newton's Third Law of Motion (Action-Reaction).

Positive transfer occurs when previous learning facilitates the acquisition of a new skill. Since the tennis serve was learned before the volleyball serve and aids in its execution, this is an example of proactive positive transfer.

Award 1 mark for selecting proactive positive transfer.

During an eccentric contraction, the muscle is actively lengthening under tension to control the movement against gravity. In a squat, during the downward phase, the quadriceps (agonist muscles) lengthen to control the rate of knee flexion.

Award 1 mark for identifying that during the eccentric phase, muscle length increases while maintaining tension.

Carbohydrates are stored in the body primarily as glycogen, with the majority located in skeletal muscle and a smaller but highly active reserve in the liver.

Award 1 mark for identifying glycogen in the liver and skeletal muscle.

Self-Determination Theory (SDT) posits that there are three basic psychological needs that must be satisfied to support optimal functioning and intrinsic motivation: autonomy, competence, and relatedness.

Award 1 mark for identifying autonomy, competence, and relatedness.

The interactionist approach views personality and behavior as a result of the interaction between stable internal traits (the individual's characteristics) and the situational context (the environment).

Award 1 mark for identifying that behavior is determined by the combination of stable traits and situational factors.

Chronic aerobic training leads to physiological adaptations including cardiac hypertrophy (specifically left ventricular volume expansion) which increases stroke volume. Consequently, to maintain the same resting cardiac output, resting heart rate decreases (bradycardia).

Award 1 mark for selecting lower resting heart rate and larger stroke volume.

During high-intensity exercise, sympathetic nervous system stimulation causes vasoconstriction in non-essential organs (like the digestive tract) and vasodilation in active skeletal muscles to meet the increased demand for oxygen and nutrients. Blood flow to the brain is maintained, and blood flow to the heart increases.

Award [1] for the correct option C. No partial credit is given for incorrect answers.

Top-spin causes the boundary layer of air on top of the ball to oppose the oncoming airflow, decreasing relative velocity and creating a high-pressure zone. Air below the ball flows faster, creating low pressure. This pressure difference creates a downward force, causing the ball to dive downwards.

Award [1] for the correct option A. No partial credit is given for incorrect answers.

Intrinsic feedback is sensory information that is naturally available to the performer during or after the movement. Knowledge of performance relates to the characteristics of the movement or execution rather than the ultimate outcome of the shot. Feeling the vibration of the frame is intrinsic knowledge of performance.

Award [1] for the correct option B. No partial credit is given for incorrect answers.

During the upward phase of a push-up, the body is raised away from the floor, requiring elbow extension. The prime mover for elbow extension is the triceps brachii, which shortens under tension (concentric contraction).

Award [1] for the correct option B. No partial credit is given for incorrect answers.

High-glycemic index (GI) carbohydrates are rapidly digested and absorbed, causing a fast rise in blood glucose levels. This triggers a high release of insulin, which maximizes glucose uptake into muscle cells for rapid glycogen resynthesis.

Award [1] for the correct option B. No partial credit is given for incorrect answers.

In Weiner's Attribution Theory, luck is classified as an external factor (outside the athlete's body/control), unstable (it can change unpredictably from task to task), and uncontrollable (the athlete cannot influence it).

Award [1] for the correct option B. No partial credit is given for incorrect answers.

Drive Theory proposes a linear relationship where higher arousal levels lead to better performance. The Inverted-U Hypothesis proposes a curvilinear relationship where performance increases with arousal up to an optimal midpoint, beyond which further arousal impairs performance.

Award [1] for the correct option A. No partial credit is given for incorrect answers.

NACH (Need to Achieve) athletes typically seek out challenging but realistic situations (such as a 50 percent probability of success) where they can take personal responsibility for the outcome, value feedback, and are motivated by the challenge of pride in success.

Award [1] for the correct option A. No partial credit is given for incorrect answers.

During exercise, blood flow is shunted away from non-essential visceral organs to support the metabolically active skeletal muscles. While absolute blood flow to the brain remains relatively constant, the kidneys experience the most drastic relative reduction in their percentage share of the total cardiac output (dropping from approximately 20% at rest to around 1% during maximal exercise).

Award [1] mark for identifying C as the correct option.

In a third-class lever system, the effort force is applied between the fulcrum and the load. This is the most common lever class found in the human body, facilitating speed and range of motion at the expense of force.

Award [1] mark for identifying C as the correct option.

The autonomous stage of learning is characterized by skills becoming automatic, requiring little to no conscious cognitive processing. This frees up the performer's attentional capacity to focus on external cues or higher-level tactics and artistic expression.

Award [1] mark for identifying C as the correct option.

During the downward phase of a squat, the knee flexes under the resistance of gravity. The quadriceps femoris lengthens while generating force to control the descent, which is defined as an eccentric contraction.

Award [1] mark for identifying B as the correct option.

Consuming high-glycemic index carbohydrates within the first 30 minutes post-exercise maximizes muscle glycogen resynthesis. This timing takes advantage of elevated insulin sensitivity and GLUT-4 transporter activity.

Award [1] mark for identifying B as the correct option.

The interactionist perspective proposes that behavior is determined by the interaction between a person's personality traits and the situational factors of their environment, typically represented by the formula \(B = f(P, E)\).

Award [1] mark for identifying C as the correct option.

Intrinsic motivation refers to engaging in an activity for the inherent satisfaction of the activity itself, rather than for some separable consequence, external reward, or pressure.

Award [1] mark for identifying B as the correct option.

Somatic anxiety represents the physiological manifestations of arousal and anxiety, such as sweating, elevated heart rate, muscle tension, and nausea, as opposed to cognitive anxiety, which relates to negative thoughts and worries.

Award [1] mark for identifying B as the correct option.

At the onset of exercise, the rapid initial increase in heart rate (up to approximately 100 beats per minute) is caused by the withdrawal of parasympathetic (vagal) nerve activity. Beyond this point, further increases in heart rate are driven by the activation of the sympathetic nervous system and the release of catecholamines (epinephrine and norepinephrine).

[1] Award 1 mark for identifying C as the correct mechanism.

Due to topspin, the top surface of the ball rotates forward (against the direction of relative airflow), which slows down the boundary layer of air on top. This results in lower air velocity and consequently higher pressure on top of the ball (according to Bernoulli's principle). Conversely, the bottom surface rotates with the airflow, increasing velocity and lowering pressure. This pressure difference creates a downward Magnus force, causing the ball to dip.

[1] Award 1 mark for identifying B as the correct statement explaining the Magnus effect on a topspin ball.

Welford's information processing model follows this logical sequence: sensory input is received, filtered/interpreted via perception, stored temporarily in the short-term memory store, processed to make a decision (decision making), and then instructions are organized through effector control to signal the muscles (effectors).

[1] Award 1 mark for selecting A.

According to the sliding filament theory, actin (thin) and myosin (thick) filaments do not change their actual length. Instead, they slide past each other. This causes the I-band (containing only thin filaments) and the H-zone (containing only thick filaments) to shorten, while the A-band (representing the full length of the thick filaments) remains unchanged in width.

[1] Award 1 mark for selecting B.

Consuming low-GI (Glycemic Index) carbohydrates 3 to 4 hours prior to prolonged exercise is recommended because they are digested and absorbed slowly. This prevents a rapid rise and subsequent crash in blood glucose (insulin spike), providing a steady supply of energy throughout the event.

[1] Award 1 mark for identifying B as the correct dietary recommendation.

The Interactionist Theory suggests that behavior (B) is a function (f) of personality (P) and the environment (E), i.e., \( B = f(P, E) \). It argues that stable traits and situational factors interact to shape how an athlete behaves in a sporting context.

[1] Award 1 mark for identifying C as the correct personality theory.

Autonomy refers to the need to feel in control of one's own actions, choices, and destiny. By allowing players to design their own plays, the coach gives them a sense of choice and ownership, thereby supporting their need for autonomy.

[1] Award 1 mark for selecting B.

Catastrophe Theory (Hardy and Fazey) predicts that physiological arousal is beneficial for performance up to an optimal level, but only if cognitive anxiety is low. If cognitive anxiety is high, reaching high levels of physiological arousal leads to a sudden, catastrophic drop in performance.

[1] Award 1 mark for identifying C as the correct theory.

(a) Difference at 90 minutes:
\(4.9\text{ mmol/L} - 3.6\text{ mmol/L} = 1.3\text{ mmol/L}\)

(b) Description of RPE trends:
- For both conditions, RPE increases progressively throughout the 120 minutes.
- The rate of increase in RPE is greater in the PLA condition compared to the CHO condition.
- While both start at an identical RPE of 6, the gap between conditions widens over time (e.g., a difference of 1 point at 30 minutes vs. a difference of 4 points at 120 minutes).

(c) Physiological reasons for RPE difference at 120 mins:
- In the PLA trial, blood glucose levels drop significantly (to 3.2 mmol/L), indicating hypoglycemia and depletion of glycogen stores.
- Low blood glucose reduces the rate of glucose uptake by the central nervous system/brain.
- This leads to central fatigue, where motor cortex output must increase to maintain the same power output, raising the subjective perception of effort.
- In the CHO trial, exogenous carbohydrate ingestion maintains blood glucose levels (at 4.7 mmol/L), providing an active substrate for both active skeletal muscles and the brain, delaying central and peripheral fatigue.

(d) Advantages of the experimental design:
- Double-blind: Prevents participant bias (placebo effect) and researcher expectancy bias, as neither party knows which fluid is administered.
- Randomized: Minimizes order effects (such as learning effects, fitness gains, or residual fatigue from the first trial) by varying the sequence of trials.
- Crossover: Allows each participant to act as their own control, which minimizes the confounding effects of inter-individual variability (e.g., base fitness, metabolic rate).

(a) [1 max]
- Award [1] for 1.3 (or 1.3 mmol/L).

(b) [3 max]
- Award [1] for noting that RPE increases continuously in both conditions.
- Award [1] for noting that RPE increases faster/is higher in the PLA condition than the CHO condition.
- Award [1] for quantification of the difference (e.g., identical at 0 mins but 4 points higher in PLA at 120 mins).

(c) [4 max]
- Award [1] for identifying that blood glucose drops significantly/hypoglycemia occurs in the PLA trial (to 3.2 mmol/L) due to glycogen depletion.
- Award [1] for linking low blood glucose to reduced energy availability/glucose supply to the central nervous system/brain.
- Award [1] for explaining that central fatigue increases motor unit recruitment effort, which elevates the perception of exertion (RPE).
- Award [1] for explaining that CHO ingestion maintains circulating blood glucose, sparing muscle glycogen or serving as a direct fuel, which preserves neuromuscular efficiency and lowers RPE.

(d) [3 max]
- Award [1] for explaining the benefit of a double-blind setup (reduces participant/researcher bias).
- Award [1] for explaining the benefit of randomization (mitigates order/learning/fatigue effects).
- Award [1] for explaining the benefit of a crossover design (controls for individual differences by using participants as their own control).

(a) Minimalist footwear.

(b) Comparison of parameters:
- Peak vGRF is 1.2 BW (50%) higher in the minimalist shoe (3.6 BW) compared to the traditional cushioning shoe (2.4 BW).
- Time to reach peak force is three times longer in the traditional cushioning shoe (45 ms) than in the minimalist shoe (15 ms).
- Traditional cushioning shoes distribute the impact energy over a significantly longer duration, resulting in a lower peak impact force.

(c) Biomechanical mechanisms of cushioning:
- Based on the impulse-momentum relationship, Impulse is the product of Force and Time (\(I = F
\times
\Delta t\)).
- For a given landing, the change in momentum (impulse required to stop the body) is constant.
- Cushioning materials (e.g., EVA foam midsoles) compress upon contact, which increases the time of deceleration (\(\Delta t\)).
- Because impact time is increased, the average and peak impact forces (\(F\)) acting on the body are minimized, reducing the mechanical stress and potential for overuse injuries in bones, joints, and tendons.

(d) Limitations of the laboratory study:
- Simple vertical drop landings (straight down) do not replicate multidirectional movements (e.g., cutting, pivoting, rapid deceleration) common in team sports.
- Laboratory conditions utilize fixed force plates which lack the varying friction, compliance, and unevenness of real sports surfaces (e.g., natural grass, turf).
- Controlled drops lack the psychological distress, fatigue, or cognitive load of game situations which can alter muscle pre-activation and landing mechanics.

(a) [1 max]
- Award [1] for Minimalist.

(b) [3 max]
- Award [1] for stating that peak vGRF is higher in minimalist shoes (or lower in cushioning shoes).
- Award [1] for stating that time to peak force is shorter in minimalist shoes (or longer in cushioning shoes).
- Award [1] for a comparative synthesis, e.g., cushioning shoes spread the force over a longer time duration, reducing the peak force magnitude.

(c) [4 max]
- Award [1] for referencing the impulse-momentum relationship: \(\text{Impulse} = F \Delta t\) (or \(F = \frac{\Delta p}{\Delta t}\)).
- Award [1] for explaining that the total change in momentum (impulse) during the landing is constant (mass and velocity at touchdown are constant).
- Award [1] for stating that cushioning materials deform/compress, directly increasing the duration of the impact (\(\Delta t\)).
- Award [1] for concluding that an increased time of impact results in lower peak vertical forces (\(F\)), thereby reducing mechanical stress on skeletal structures.

(d) [3 max]
- Award [1] for explaining that static drop tests lack the multidirectional/horizontal movements of team sports.
- Award [1] for noting that laboratory force plates do not simulate real sports surfaces (e.g., turf, grass, court floors).
- Award [1] for mentioning the lack of game-like conditions, such as fatigue, defensive pressure, or unpredictability, which alter landing patterns.

(a) Cardiovascular drift is characterized by a gradual, progressive increase in heart rate accompanied by a parallel decrease in stroke volume during prolonged, submaximal steady-state exercise, while cardiac output remains relatively constant.

(b) During prolonged exercise in a hot environment, the body increases sweating rates to aid thermoregulation through evaporative cooling. This loss of fluid leads to a reduction in blood plasma volume. A lower plasma volume reduces the venous return (preload) to the heart. According to Starling's Law of the heart, a reduced venous return decreases the end-diastolic volume, which in turn causes a reduction in stroke volume. To compensate for the reduced stroke volume and maintain a constant cardiac output (since \(Q = HR \times SV\)), the heart rate must progressively increase.

(c) At rest, about 15-20% of cardiac output is directed to active skeletal muscles, while the majority (approx. 80-85%) is directed to the kidneys, liver, stomach, and other visceral organs. During maximal exercise, this distribution changes dramatically: up to 80-85% of cardiac output is redirected to the working skeletal muscles via vasodilation of active arterioles. Conversely, blood flow to visceral organs is severely restricted via vasoconstriction of inactive vascular beds. While absolute blood flow to the brain is maintained, its percentage of the total cardiac output decreases. Blood flow to the skin also initially increases for cooling but may be restricted during maximal exertion to prioritize muscular oxygenation.

(d) The three primary functions of the conducting airways are:
1. Offering a low-resistance pathway for airflow.
2. Warming the inspired air to core body temperature.
3. Humidifying/moistening the inspired air to protect the delicate mucosal surfaces.
4. Filtering/cleaning the air using cilia and mucus to trap foreign particles before they reach the alveoli.

(a) Award [1] for noting the progressive increase in heart rate and [1] for the parallel decrease in stroke volume during prolonged steady-state exercise.
- Accept reference to cardiac output remaining constant for clarification.

(b) Award [1] per valid physiological mechanism step, up to [5]:
- Body temperature increases, triggering sweating for heat dissipation [1].
- Sweating causes a reduction in blood plasma volume [1].
- Reduced plasma volume leads to lower venous return/preload [1].
- Lower venous return causes a decrease in stroke volume (Starling's Law) [1].
- Cardiac output must be maintained (\(Q = HR \times SV\)) [1].
- Therefore, heart rate increases to compensate [1].
- Redirection of blood flow to the skin for heat dissipation also decreases central blood volume/stroke volume [1].

(c) Award [1] per comparative point, up to [4]:
- At rest, only 15-20% of blood flow goes to skeletal muscle; during maximal exercise, this increases to 80-85% [1].
- At rest, digestive/visceral organs receive the majority of cardiac output; during maximal exercise, vasoconstriction reduces this drastically [1].
- Coronary blood flow (heart muscle) increases absolutely during exercise [1].
- Brain blood flow remains relatively constant in absolute terms but represents a lower overall percentage during exercise [1].

(d) Award [1] per valid function of the conducting airways, up to [3]:
- Low-resistance pathway for airflow [1].
- Warms the air [1].
- Humidifies/moistens the air [1].
- Filters/cleans the air (mucus/cilia) [1].

(a) A scalar quantity has magnitude (size) only, whereas a vector quantity has both magnitude and a specific direction. For example, mass or speed is a scalar quantity, whereas velocity, acceleration, or force is a vector quantity.

(b) Newton's laws apply as follows:
- Newton's First Law (Law of Inertia): An object remains at rest unless acted upon by an external force. The sprinter remains stationary in the starting blocks until they exert a net external force through muscular contraction to overcome their state of inertia.
- Newton's Second Law (Law of Acceleration): The rate of change of momentum is proportional to the applied force and occurs in the direction of the force (\(F = ma\)). The acceleration of the sprinter out of the blocks is directly proportional to the force they exert against the blocks, in the forward direction.
- Newton's Third Law (Law of Action and Reaction): For every action force, there is an equal and opposite reaction force. As the sprinter pushes backward and downward against the starting blocks (action force), the blocks exert an equal and opposite force forward and upward against the sprinter (reaction force), driving them forward.

(c) Levers are classified based on the relative positions of the fulcrum (pivot), the effort (force), and the load (resistance):
- First-class lever: The fulcrum lies between the effort and the load. Example: Nodding the head (atlanto-occipital joint acts as the fulcrum, the head weight is the load, and the neck extensor muscles provide the effort).
- Second-class lever: The load lies between the fulcrum and the effort. Example: Standing on tiptoes (metatarsophalangeal joint is the fulcrum, the body weight acting through the foot is the load, and the gastrocnemius/soleus contraction is the effort).
- Third-class lever: The effort lies between the fulcrum and the load. Example: Elbow flexion (elbow joint is the fulcrum, the insertion of the biceps brachii tendon is the effort, and the weight of the forearm/hand is the load).

(a) Award [1] for distinguishing definition (scalar has magnitude only, vector has magnitude and direction).
- Award [1] for a correct scalar example (e.g., speed, mass, distance).
- Award [1] for a correct vector example (e.g., velocity, force, acceleration, displacement).

(b) Award up to [2] per law clearly explained in context (total [6]):
- Newton's 1st Law: Athlete remains at rest until a force is exerted [1]; muscular contraction provides the external force to overcome inertia [1].
- Newton's 2nd Law: Explains relationship \(F=ma\) [1]; greater force exerted against the blocks results in greater acceleration out of the blocks [1].
- Newton's 3rd Law: Action-reaction pair [1]; pushing backward against the blocks (action) results in the blocks pushing the runner forward (reaction) [1].

(c) Award marks for lever classification and matching anatomical examples, up to [5]:
- Award [1] for describing/defining first-class lever (Fulcrum in middle) AND [1] for a correct matching example (e.g., extension/flexion of the neck at atlanto-occipital joint).
- Award [1] for describing/defining second-class lever (Load in middle) AND [1] for a correct matching example (e.g., plantar flexion of the ankle when standing on tiptoes).
- Award [1] for describing/defining third-class lever (Effort in middle) AND [1] for a correct matching example (e.g., elbow flexion using biceps brachii).
- Max [3] marks for lever descriptions, Max [2] marks for valid anatomical examples.

(a) Chronic cardiovascular adaptations to endurance training include: (1) Increased left ventricular volume (eccentric hypertrophy), which increases stroke volume. (2) Decreased resting and submaximal heart rate (bradycardia) due to increased parasympathetic/vagal tone and increased stroke volume. (3) Increased maximal cardiac output during maximal exercise, primarily driven by the increase in maximal stroke volume. (4) Increased blood plasma volume, which enhances venous return and stroke volume via the Frank-Starling mechanism. (5) Increased capillarization of skeletal muscle, improving oxygen delivery and diffusion to active muscle fibers. (6) Increased arteriovenous oxygen difference (\(a-vO_2\) diff) due to enhanced oxygen extraction by muscles. (b) Cardiovascular drift is characterized by a gradual decrease in stroke volume and a parallel increase in heart rate during prolonged, steady-state exercise, particularly in hot environments: (1) Prolonged exercise leads to dehydration and increased sweating to regulate body temperature. (2) Sweat loss reduces blood plasma volume, leading to increased blood viscosity and reduced venous return. (3) Active vasodilation of cutaneous blood vessels occurs to direct blood to the skin for cooling, further reducing venous return to the heart. (4) According to the Frank-Starling law, reduced venous return decreases end-diastolic volume and thus decreases stroke volume. (5) To maintain a constant cardiac output (since Cardiac Output = Stroke Volume \(\times\) Heart Rate), the heart rate must progressively increase. (c) Physiological factors limiting \(VO_2\text{max}\) can be divided into central and peripheral factors: (1) Cardiac output (central factor): The maximal stroke volume and the heart's ability to pump large volumes of oxygenated blood is a primary limitation. (2) Pulmonary system (central factor): Oxygen diffusion capacity at the lungs and alveolar ventilation, though rarely limiting in healthy untrained individuals, can limit elite athletes who experience exercise-induced arterial hypoxemia. (3) Oxygen carrying capacity of the blood (central factor): Hemoglobin concentration and total red blood cell volume determine how much oxygen can be transported. (4) Skeletal muscle capillarization (peripheral factor): The capillary density around muscle fibers limits the surface area and time available for oxygen diffusion from blood into the muscle. (5) Mitochondrial density and oxidative enzyme activity (peripheral factor): The capacity of the muscle cells to utilize oxygen to produce ATP via aerobic pathways.

Part (a) [6 marks max]: Award 1 mark per valid adaptation described up to 6 marks. • Increased left ventricular volume / cardiac hypertrophy. • Increased stroke volume at rest, submaximal, and maximal exercise. • Decreased resting and submaximal heart rate (bradycardia). • Increased capillarization of skeletal muscle. • Increased plasma volume. • Increased arterio-venous oxygen difference (\(a-vO_2\) diff). • Increased maximal cardiac output. Part (b) [6 marks max]: Award 1 mark for each point explained up to 6 marks. • Cardiovascular drift is the gradual increase in heart rate and decrease in stroke volume over time during prolonged steady-state exercise. • Sweating occurs to facilitate heat loss/thermoregulation. • Sweat loss leads to a reduction in blood plasma volume. • Reductions in plasma volume increase blood viscosity and decrease venous return. • Skin blood flow increases (vasodilation) to dissipate heat, further reducing central venous pressure and venous return. • Decreased venous return reduces end-diastolic volume and stroke volume (Frank-Starling mechanism). • To maintain cardiac output (\(Q = \text{HR} \times \text{SV}\)), heart rate must increase to compensate for the falling stroke volume. Part (c) [8 marks max]: Award 1 mark for each discussion point up to 8 marks (allocate up to 4 marks for central factors and 4 marks for peripheral factors). Central limitations: • Cardiac output (\(Q\)) / Stroke Volume (\(SV\)): The heart's ability to pump blood is the primary limiting factor for most individuals. • Hemoglobin concentration / Red blood cell mass: Determines the oxygen-carrying capacity of the blood. • Pulmonary diffusion capacity: Alveolar-capillary diffusion can limit elite endurance athletes due to rapid transit times. Peripheral limitations: • Capillary density: Limits the rate of oxygen extraction and diffusion into the muscle tissue. • Mitochondrial density/volume: Limits the rate at which oxygen can be utilized in the electron transport chain. • Myoglobin concentration: Limits the transport of oxygen within the muscle cell. • Oxidative enzymes (e.g., SDH): Affect the rate of aerobic metabolism.

(a) Newton's laws of motion applied to a sprinter: (1) Newton's First Law (Law of Inertia) states that an object remains at rest or in uniform motion unless acted upon by an external force. The sprinter remains stationary in the blocks until they exert a muscular force to overcome their inertia and initiate motion. (2) Newton's Second Law (Law of Acceleration) states that the acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (\(F = ma\)). To maximize acceleration, the sprinter must apply a large force against the blocks in the desired direction of travel. A sprinter with less mass requires less force to achieve the same acceleration. (3) Newton's Third Law (Law of Action-Reaction) states that for every action, there is an equal and opposite reaction. The sprinter pushes backward and downward against the starting blocks (action force), and the blocks push forward and upward against the sprinter's feet with equal magnitude (reaction force), propelling them forward. (b) Factors influencing the flight path of a projectile: (1) Projection speed: The initial velocity of release. It is the most important factor in determining horizontal distance; higher speed increases both height and distance. (2) Projection angle: The angle of release relative to the horizontal. The optimal angle for maximum distance is \(45^\circ\) if release and landing heights are equal; it is less than \(45^\circ\) if release height is higher than landing height (e.g., shot put). (3) Projection height: The vertical height at which the projectile is released relative to the ground. A higher release height increases flight time and therefore horizontal distance. (4) Gravity: Accelerates the projectile downwards at \(9.81 \text{ m/s}^2\), pulling it back to earth and creating a parabolic trajectory. (5) Air resistance (aerodynamic factors): Forces such as drag and lift that can alter the flight path depending on the projectile's shape, surface texture, and spin. (c) Applying the Bernoulli principle (Magnus effect) to a spinning ball: (1) The Bernoulli principle states that fluid pressure is inversely proportional to fluid velocity. (2) When a ball spins in flight, it drags a boundary layer of air around with it due to friction. (3) On one side of the spinning ball, the surface of the ball is moving in the same direction as the oncoming airflow, which accelerates the air speed on that side. (4) On the opposite side, the surface of the ball is moving against the oncoming airflow, which decelerates the air speed. (5) According to Bernoulli's principle, the high-velocity side experiences a reduction in fluid pressure (low pressure zone). (6) The low-velocity side experiences an increase in fluid pressure (high pressure zone). (7) This pressure differential creates a pressure gradient, generating a net force (Magnus force) acting from the high-pressure side to the low-pressure side. (8) This force causes the flight path of the ball to curve or drift in the direction of the low-pressure side (e.g., topspin causes downward curvature, backspin causes upward lift, sidespin causes lateral curving).

Part (a) [6 marks max]: Award up to 2 marks per law applied correctly. • Newton's First Law: Sprinter remains stationary in the blocks until an unbalanced muscular force is applied (1 mark). Mention of overcoming inertia to start moving (1 mark). • Newton's Second Law: Acceleration is proportional to force applied and inversely proportional to mass (1 mark). To accelerate faster, the sprinter must apply a greater force against the blocks (1 mark). • Newton's Third Law: Action-reaction force pairs (1 mark). Sprinter pushes back/down on the blocks, blocks push forward/up on the sprinter with equal force (1 mark). Part (b) [6 marks max]: Award 1 mark per outline point up to 6 marks. • Speed of release: High speed increases distance/height (1 mark). • Angle of release: Determines trajectory shape; optimal is ~\(45^\circ\) for equal heights (1 mark). • Height of release: Higher release point increases flight time/distance (1 mark). • Gravity: Constantly acts downwards, pulling the projectile to the ground (1 mark). • Air resistance / Drag: Slows down the horizontal velocity of the projectile (1 mark). • Spin / Lift forces: Magnus force can alter the ideal parabolic curve (1 mark). Part (c) [8 marks max]: Award 1 mark for each point explained up to 8 marks. • Bernoulli's principle states that high velocity fluid flow is associated with low pressure, and vice versa (1 mark). • A spinning ball carries a boundary layer of air with it due to surface friction (1 mark). • On the side where the spin is in the same direction as oncoming air, velocity increases (1 mark). • On the opposite side where spin opposes oncoming air, velocity decreases (1 mark). • High velocity side creates a region of low pressure (1 mark). • Low velocity side creates a region of high pressure (1 mark). • A pressure differential/gradient is established across the ball (1 mark). • This creates a net force (Magnus force) acting from high to low pressure (1 mark). • This force deflects/curves the ball from its normal parabolic flight path (1 mark).

(a) (i) Difference = 97.5% - 94.1% = 3.4% (or -3.4%). (a) (ii) An inverse/negative relationship is observed: as cognitive anxiety increases, performance decreases. (b) Intrinsic motivation is driven by internal rewards (e.g., self-satisfaction, love of the game) whereas extrinsic motivation is driven by external rewards (e.g., trophies, money, praise). Intrinsic is more sustainable. (c) McClelland's theory proposes two motives: Need to Achieve (nAch) and Need to Avoid Failure (nAF). Group A has high nAch, meaning they seek challenges and thrive under pressure, leading to improved performance. Group B has high nAF, meaning they fear failure, leading to high anxiety and performance decline. (d) Catastrophe theory predicts that when cognitive anxiety is high, physiological arousal beyond an optimal point causes a sudden, catastrophic drop in performance. Group B's high anxiety made them vulnerable to this. (e) Weiner's attribution theory includes stability, causality, and control. Group B might attribute failure to external, unstable, or uncontrollable factors (self-serving bias) to protect self-esteem, or internal, stable, uncontrollable factors, leading to learned helplessness.

(a) (i) Award [1] for 3.4% or -3.4%. (a) (ii) Award [1] for describing a negative/inverse relationship (or stating performance decreases as anxiety increases). (b) Award [1] for defining intrinsic motivation; [1] for defining extrinsic motivation; [1] for distinguishing their impact on long-term participation or pressure. (c) Award up to [6]: [1] for identifying nAch and nAF; [2] for linking Group A to high nAch/seeking challenges/improving performance; [2] for linking Group B to high nAF/fear of failure/decline under pressure; [1] for depth/coherence of discussion. (d) Award up to [6]: [1] for explaining interaction of cognitive anxiety and physiological arousal; [1] for stating low cognitive anxiety results in inverted-U; [1] for stating high cognitive anxiety leads to sudden catastrophe drop; [1] for stating this drop is non-linear/sudden; [1] for stating recovery requires a major reduction in arousal; [1] for linking to the data (Group B's high cognitive anxiety). (e) Award up to [8]: [1] for naming Weiner's three dimensions; [2] for explaining stability (stable vs unstable) with sports examples; [2] for explaining locus of causality (internal vs external) with sports examples; [2] for explaining locus of control (controllable vs uncontrollable) with sports examples; [1] for applying this to Group B's performance drop (e.g., protecting ego via self-serving bias or experiencing learned helplessness).

(a) (i) Somatic anxiety decreased from 25.8 to 14.2 (by 11.6 points). Free-throw success rate increased from 62.4% to 78.6% (by 16.2 percentage points). (a) (ii) Physical symptoms include: increased heart rate/palpitations, muscle tension/stiffness, and heavy sweating. (b) Cognitive techniques focus on the mind (e.g., positive self-talk, imagery) to reduce worry. Somatic techniques focus on physiological responses (e.g., PMR, deep breathing) to reduce muscle tension. (c) PMR works by systematically tensing and relaxing muscle groups, enabling athletes to detect tension and activate the parasympathetic nervous system, reducing physiological arousal. (d) Outcome goals (e.g., winning) are uncontrollable and increase anxiety. Performance goals (e.g., achieving 80% success) and process goals (e.g., standard shooting technique) are highly controllable, focus attention, and lower state anxiety. (e) Bandura's theory proposes four sources: performance accomplishments (successful past free throws), vicarious experiences (watching peers succeed), verbal persuasion (coach encouragement), and physiological states (interpreting low anxiety as readiness). All four were optimized by the PST program, enhancing self-efficacy and performance.

(a) (i) Award [1] for describing the somatic anxiety decrease with values; [1] for describing the free-throw success rate increase with values. (a) (ii) Award [1] per valid somatic symptom of anxiety, up to [3] (e.g., muscle tension, sweating, elevated heart rate, nausea, dry mouth). (b) Award [1] for explaining cognitive techniques; [1] for a cognitive example (e.g., self-talk); [1] for explaining somatic techniques; [1] for a somatic example (e.g., PMR). (c) Award up to [4]: [1] for systematic tensing and relaxing of muscle groups; [1] for developing awareness of tension vs. relaxation; [1] for triggering the parasympathetic response (lowering heart rate/blood pressure); [1] for explaining how physical relaxation calms the mind (somatic-cognitive connection). (d) Award up to [6]: [2] for evaluating outcome goals (benefits vs. high anxiety/lack of control); [2] for evaluating performance and process goals (high controllability, focus on self, reduction of anxiety); [2] for recommending a balanced goal-setting strategy (e.g., goal staircase). (e) Award up to [6]: [1] for defining self-efficacy; [4] for identifying and explaining each of the four sources (performance accomplishments, vicarious experiences, verbal persuasion, physiological/emotional states); [1] for explicitly linking these sources to the basketball scenario (e.g., PMR improving physiological state interpretation, increased practice success boosting performance accomplishments).