2024 IB DP Sports, Exercise and Health Science Practice Paper with Answers

During exercise, the metabolic demand for oxygen by the active skeletal muscles increases significantly. Consequently, the muscles extract a larger fraction of oxygen from the arterial blood, which reduces the oxygen concentration of the mixed venous blood returning to the heart. This leads to a wider gap, or an increase, in the arterio-venous oxygen difference (\(a\text{-}\bar{v}\text{O}_2 \text{ diff}\)).

Award [1] for the correct answer (C). All other options represent incorrect physiological adaptations or incorrect directions of change in blood oxygen parameters.

During a standing heel raise, the foot acts as a second-class lever where the load (body weight acting through the ankle joint) lies between the fulcrum (the metatarsophalangeal joints at the ball of the foot) and the effort (the upward pull exerted by the contracting gastrocnemius and soleus muscles via the Achilles tendon).

Award [1] for the correct option (B). Other options misclassify either the lever system class or the anatomical components acting as the fulcrum, effort, and load.

As glycogen stores deplete, active muscle cells must rely increasingly on lipid (fat) oxidation to regenerate ATP. Because lipid oxidation requires more oxygen per mole of ATP synthesized compared to carbohydrate oxidation, the maximum sustainable work rate (and therefore the athlete's pace) decreases.

Award [1] for the correct option (B). Other options incorrectly identify metabolic products or pathways associated with lipid metabolism and glycogen depletion.

This feedback is terminal because it is delivered after the movement is completed. It is classified as Knowledge of Performance (KP) because it provides information about the characteristics of the movement pattern (the wrist angle) rather than the outcome of the movement (the success or trajectory of the ball).

Award [1] for the correct option (C). Option A is incorrect as the feedback is not concurrent or intrinsic. Option B is incorrect because it relates to performance quality, not the results. Option D is incorrect because the coach provides extrinsic, not intrinsic, information.

During the downward (lowering) phase of a squat, the quadriceps femoris group contracts to control the rate of knee flexion against the force of gravity. This is an eccentric contraction (the muscle is active while lengthening), during which the individual sarcomeres are pulled apart, resulting in an increase in sarcomere length.

Award [1] for the correct option (C). Other options fail to correctly combine the active eccentric contraction with the corresponding physiological increase in sarcomere length.

Mental imagery/rehearsal is a cognitive strategy used to enhance self-efficacy, improve focus, and reinforce the motor neural pathways associated with movement execution (neuromuscular theory) without inducing physiological fatigue.

Award [1] for the correct option (B). Other options either attribute somatic (physiological) relaxation properties directly to cognitive rehearsal or mischaracterize it as a distraction technique.

Endomorphy represents the component of somatotyping associated with roundness, softness, and a physical predisposition to accumulate and store adipose tissue (body fat).

Award [1] for the correct option (C). Option A and D describe mesomorphy. Option B describes ectomorphy.

Identified regulation is an autonomous form of extrinsic motivation where an individual performs a behavior because they identify with and value its utility or benefit, even if they do not find the activity itself inherently interesting or enjoyable (e.g., training to gain fitness benefits despite finding it repetitive).

Award [1] for the correct option (B). Option A represents external regulation (tangible rewards). Option C represents intrinsic motivation (inherent enjoyment/flow). Option D represents introjected regulation (avoiding guilt/seeking approval).

In healthy, untrained individuals, stroke volume increases during incremental exercise but typically reaches a plateau at approximately 40% to 60% of \(VO_2\) max. Beyond this intensity, any further increase in cardiac output is primarily driven by increases in heart rate. This plateau occurs because the progressively higher heart rate reduces diastolic filling time, limiting end-diastolic volume and preventing further increases in stroke volume.

Award 1 mark for the correct option: B. Award 0 marks for incorrect options.

Newton's third law states that for every action, there is an equal and opposite reaction. When the sprinter pushes backward and downward against the starting blocks (action force), the starting blocks exert an equal and opposite force forward and upward on the sprinter (reaction force). This reaction force is what accelerates the sprinter forward.

Award 1 mark for the correct option: C. Award 0 marks for incorrect options.

Carbohydrates and lipids are composed of carbon, hydrogen, and oxygen atoms. Proteins contain these three elements as well, but they also uniquely contain nitrogen as a vital component of their amino acid structure (specifically in the amine group, \(-NH_2\)).

Award 1 mark for the correct option: B. Award 0 marks for incorrect options.

The feedback is extrinsic because it comes from an external source (the coach). It is Knowledge of Performance because it details the quality and execution of the movement pattern (the timing of the block off the table) that led to the outcome, rather than just stating the outcome itself (Knowledge of Results).

Award 1 mark for the correct option: B. Award 0 marks for incorrect options.

The structural hierarchy of skeletal muscle from outermost to innermost is: Epimysium (surrounds entire muscle) -> Perimysium (surrounds muscle fascicles) -> Endomysium (surrounds individual muscle fibers) -> Muscle fiber (muscle cell) -> Myofibril (thread-like structures within the fiber containing myofilaments) -> Sarcomere (the functional, contractile unit between two Z-lines).

Award 1 mark for the correct option: A. Award 0 marks for incorrect options.

Intrinsic motivation occurs when an individual engages in an activity for the inherent satisfaction, enjoyment, and challenge of the activity itself, rather than for external rewards (external regulation) or internal pressures/guilt (introjected regulation).

Award 1 mark for the correct option: D. Award 0 marks for incorrect options.

Patellar tendinopathy (often called jumper's knee) is a chronic overuse injury caused by repetitive stress on the patellar tendon over time. Hamstring tears, ankle sprains, and shoulder dislocations are acute injuries caused by sudden, specific traumatic events during physical activity.

Award 1 mark for the correct option: C. Award 0 marks for incorrect options.

The Inverted-U hypothesis suggests that there is an optimal level of arousal for peak performance. However, this optimal level shifts depending on the nature of the task. For highly complex tasks requiring fine motor control, precision, and decision-making, the optimal level of arousal is lower to prevent muscle tension and loss of concentration. For simple, gross tasks requiring strength and power, a higher level of arousal is beneficial.

Award 1 mark for the correct option: B. Award 0 marks for incorrect options.

Endurance training leads to an increase in resting stroke volume due to increased left ventricular volume and myocardial contractility. Consequently, resting heart rate decreases (bradycardia) due to increased parasympathetic tone, maintaining resting cardiac output. During submaximal exercise, cardiac output remains relatively unchanged because the increased stroke volume is balanced by a lower heart rate at any given submaximal intensity.

Award [1] for the correct answer: A.

With topspin, the top surface of the ball rotates forward (against the oncoming air), which slows the air flow over the top. The bottom surface rotates backward (in the direction of the oncoming air), which accelerates the air flow underneath. According to Bernoulli's principle, higher velocity results in lower pressure. Therefore, air velocity is higher and pressure is lower on the bottom surface, creating a downward force (Magnus effect) that causes the ball to dip.

Award [1] for the correct answer: B.

A positively accelerating curve represents a situation where early practice yields little progress, but later practice leads to rapid, significant improvements as the learner grasps the task mechanics.

Award [1] for the correct answer: C.

Eating low GI carbohydrates 3-4 hours prior to prolonged exercise is ideal as it provides a slow, steady release of glucose, avoiding a rapid spike in insulin which could otherwise trigger premature hypoglycemia at the start of the event.

Award [1] for the correct answer: B.

During the downward phase of a squat, gravity is flexing the knees. The quadriceps (knee extensors) must lengthen under tension (eccentric contraction) to control this flexion and prevent the person from falling too quickly.

Award [1] for the correct answer: B.

External imagery occurs when the person views themselves from an outside perspective (third-person view), like watching a video of oneself. Internal imagery involves visualizing from behind one's own eyes (first-person view).

Award [1] for the correct answer: B.

Identified regulation is a form of extrinsic motivation where an activity is accepted and valued as personally important or useful, even if the activity itself is not inherently enjoyable or intrinsically motivating.

Award [1] for the correct answer: B.

Somatic anxiety refers to the physical symptoms of anxiety, such as sweating, increased heart rate, and muscle tension. Cognitive anxiety, on the other hand, refers to the mental symptoms, such as worry, negative expectations, and apprehension.

Award [1] for the correct answer: B.

During prolonged exercise in a warm environment, sweat rate increases to aid thermoregulation, which reduces blood plasma volume. This reduction in plasma volume lowers venous return and stroke volume (SV). To maintain cardiac output (\(Q = \text{HR} \times \text{SV}\)), heart rate (HR) must increase. This phenomenon is known as cardiac drift.

Award [1] mark for identifying the correct physiological mechanism: a decrease in stroke volume leading to a compensatory increase in heart rate to maintain cardiac output.

With topspin, the top of the ball rotates forward, opposing the oncoming airflow. This creates a region of lower relative air velocity on top, which according to Bernoulli's principle results in higher pressure. The bottom of the ball rotates in the same direction as the airflow, increasing relative velocity and creating lower pressure. The resulting pressure gradient pushes the ball downward.

Award [1] mark for identifying that low velocity of air on top creates high pressure on top, creating a downward force.

Immediately after strenuous exercise, muscle cells are highly sensitive to insulin, and glycogen synthase activity is high. Consuming high glycemic index (GI) foods rapidly increases blood glucose and insulin levels, optimizing the rate of muscle glycogen replenishment. Low GI foods are better suited for pre-exercise meals to provide sustained energy, and high GI foods are preferred during exercise for rapid absorption.

Award [1] mark for identifying high GI foods immediately post-exercise as the optimal strategy for rapid glycogen replenishment.

A gymnast's vault routine is a serial skill because it consists of several discrete movements (the run-up, takeoff, handspring, flight, and landing) linked together in a specific sequence. It is a closed skill because the environment is stable, predictable, and self-paced. It is a gross motor skill because it requires large muscle groups and full-body coordination.

Award [1] mark for the correct combination: Serial, closed, gross motor skill.

During the downward phase of a squat, gravity is pulling the body down, and the knee joint is flexing. To control this downward movement and prevent collapsing, the knee extensors (quadriceps) must contract while they are lengthening. This lengthening under tension is an eccentric contraction of the quadriceps.

Award [1] mark for identifying that the quadriceps contract eccentrically to control the descent.

This is a process goal because it focuses on the specific behaviors, actions, and physical execution elements of the technique (the approach run and takeoff drive) during the event. Unlike outcome goals (which focus on winning) or performance goals (which focus on personal targets like height achieved), process goals focus on the execution of the skill.

Award [1] mark for identifying this as a process goal.

Deci and Ryan's Self-Determination Theory (SDT) proposes that humans have three innate, universal psychological needs: Autonomy (the need to feel in control of one's behavior), Competence (the need to feel effective and master tasks), and Relatedness (the need to feel a sense of belonging and connection with others). Satisfying these three needs promotes intrinsic motivation.

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

Chronic aerobic training leads to several cardiovascular adaptations, including an increase in left ventricular volume and wall thickness (eccentric hypertrophy), resulting in a significantly increased stroke volume. At the level of the muscle, capillarization increases (greater capillary density), which facilitates better oxygen diffusion and delivery to the working tissues.

Award [1] mark for identifying the correct pair of adaptations: increased capillary density and increased stroke volume.

Arteriovenous oxygen difference measures the difference in oxygen content between arterial and mixed venous blood. During exercise, working muscles extract more oxygen from the arterial blood to meet the metabolic demands of aerobic respiration. Consequently, the oxygen content of venous blood decreases, leading to an increase in the \(a\text{-}v\text{O}_2\text{ diff}\).

Award [1] for selecting the correct option C.

With topspin, the top of the ball rotates against the oncoming airflow, decreasing relative air velocity and creating a high-pressure zone. The bottom of the ball rotates in the same direction as the airflow, increasing relative air velocity and creating a low-pressure zone. This pressure differential forces the ball downwards.

Award [1] for selecting the correct option B.

Post-exercise glycogen resynthesis is maximized by consuming high-glycemic index carbohydrates immediately after exercise. Adding protein can further stimulate insulin secretion, which enhances glucose uptake and glycogen storage.

Award [1] for selecting the correct option B.

The feedback is given after the movement is completed (terminal). It describes the quality or technique of the performance ('legs were slightly bent during the flight phase') rather than the outcome (such as the score or distance), making it knowledge of performance. Since it is provided by an external source (the coach), it is extrinsic, terminal knowledge of performance.

Award [1] for selecting the correct option C.

During muscle contraction, calcium ions released from the sarcoplasmic reticulum bind to troponin. This binding causes a conformational change in troponin, which shifts tropomyosin away from the active sites on the actin filament, allowing myosin heads to bind and form cross-bridges.

Award [1] for selecting the correct option A.

The '12 weeks' duration establishes a clear deadline or timeframe for achieving the goal, which corresponds directly to the 'Time-phased' (or timely) component of the SMARTER principles.

Award [1] for selecting the correct option C.

Deci and Ryan's Self-Determination Theory posits that the three fundamental psychological needs essential for facilitating intrinsic motivation are autonomy (feeling in control of one's actions), competence (feeling effective), and relatedness (feeling a sense of connection with others).

Award [1] for selecting the correct option B.

A mesomorph somatotype is characterized by high muscularity, low body fat, broad shoulders, and a narrow waist, which are structural advantages for power-based sports like sprinting.

Award [1] for selecting the correct option C.

(a) Cardiac Output \(Q = \text{Heart Rate (HR)} \times \text{Stroke Volume (SV)}\).
For Untrained rest: \(72 \text{ beats min}^{-1} \times 70 \text{ mL beat}^{-1} = 5040 \text{ mL min}^{-1} = 5.04 \text{ L min}^{-1}\).
For Trained rest: \(48 \text{ beats min}^{-1} \times 115 \text{ mL beat}^{-1} = 5520 \text{ mL min}^{-1} = 5.52 \text{ L min}^{-1}\).

(b) Stroke volume: The trained individual achieves a much higher maximal stroke volume compared to the untrained individual (170 mL vs 110 mL). The stroke volume increase from rest to maximal exercise is also greater in the trained individual (+55 mL vs +40 mL). Heart rate: The trained individual has a lower maximal heart rate than the untrained individual (185 beats \(min^{-1}\) vs 195 beats \(min^{-1}\)).

(c) Training adaptation causes cardiac hypertrophy, specifically increasing the volume of the left ventricle. This enables a much greater stroke volume per beat. Because the resting metabolic demands (and thus the resting cardiac output) remain relatively unchanged, the higher stroke volume allows the heart to maintain the same resting cardiac output with a lower heart rate (known as training bradycardia, mediated by increased vagal/parasympathetic activity).

(a) [2 marks total]
- Award [1] for correct formula and showing working: \(Q = \text{HR} \times \text{SV}\) converted to liters.
- Award [1] for both correct resting values: Untrained = 5.04 L \(min^{-1}\) and Trained = 5.52 L \(min^{-1}\) (accept values in mL if units are correct).

(b) [3 marks total]
- Award [1] for stating that the trained individual has a higher maximal stroke volume.
- Award [1] for comparing the magnitude of stroke volume change (greater increase in the trained individual).
- Award [1] for identifying that the trained individual has a lower maximal heart rate.

(c) [2 marks total]
- Award [1] for identifying cardiac hypertrophy / increased left ventricular volume, which increases resting stroke volume.
- Award [1] for linking a larger stroke volume to a lower heart rate to maintain the same resting cardiac output / increased parasympathetic tone.

(a) Distance is the complete length of the path traveled by the runner and is a scalar quantity (possessing only magnitude). Displacement is the shortest straight-line path from the starting point to the final point and is a vector quantity (possessing both magnitude and direction).

(b) Newton's third law of motion states that for every action, there is an equal and opposite reaction. When the sprinter pushes backward and downward against the starting blocks (action force), the blocks simultaneously exert an equal and opposite force forward and upward on the sprinter's feet (reaction force), pushing them forward.

(c) Impulse is the product of average force and the time during which that force is applied (\(J = F \times \Delta t\)). According to the impulse-momentum relationship, impulse is equal to the change in momentum (\(F \Delta t = m \Delta v\)). Since the sprinter's mass (m) is constant, maximizing the forward horizontal impulse directly maximizes the change in horizontal velocity (\(\Delta v\)). The sprinter can achieve this by maximizing the muscular force applied against the blocks and optimizing the duration of block contact (maintaining force over an optimal period without compromising execution speed).

(a) [2 marks total]
- Award [1] for defining distance as total path length / a scalar.
- Award [1] for defining displacement as straight-line distance in a specific direction / a vector.

(b) [2 marks total]
- Award [1] for stating Newton's third law (action and reaction are equal and opposite).
- Award [1] for explaining how pushing backward against the starting blocks results in a forward reaction force that propels the sprinter.

(c) [3 marks total]
- Award [1] for defining impulse (\(F \times t\)) and stating that it is equal to the change in momentum (\(m \Delta v\)).
- Award [1] for stating that maximizing average force output increases impulse and exit velocity.
- Award [1] for explaining that optimizing block contact time allows for a greater total impulse to be generated without slowing block clearance.

(a) Glycogen resynthesis is substantially faster and reaches a much higher level in Trial A than in Trial B over the 24-hour recovery period. In Trial A, glycogen increases by 95 mmol \(kg^{-1}\) (from 15 to 110 mmol \(kg^{-1}\)), while in Trial B it increases by only 25 mmol \(kg^{-1}\) (from 15 to 40 mmol \(kg^{-1}\)). The highest rate of resynthesis in Trial A occurs in the first 2 hours (an increase of 15 mmol \(kg^{-1}\) per hour), whereas Trial B remains extremely slow and relatively flat throughout the 24 hours (only 1.04 mmol \(kg^{-1}\) per hour).

(b) Ingestion of carbohydrates post-exercise causes a rapid elevation in blood glucose concentration. This stimulates the pancreas to secrete insulin. Insulin increases glucose uptake into the depleted muscle fibers by promoting the translocation of glucose transporter proteins (GLUT4) to the cell membrane. It also directly activates glycogen synthase, which is the key rate-limiting enzyme that catalyzes the conversion of glucose into glycogen.

(c) 1. Consuming protein (approx. 20-25g) alongside carbohydrates to promote muscle protein synthesis, repair micro-tears in muscle fibers, and slightly enhance the rate of glycogen replenishment. 2. Rehydrating with fluid containing sodium/electrolytes to replace sweat losses, restore electrolyte balance, and improve fluid retention in the body.

(a) [3 marks total]
- Award [1] for stating that Trial A has a higher rate/amount of glycogen resynthesis than Trial B.
- Award [1] for quantifying the difference (e.g. Trial A reaches 110 mmol \(kg^{-1}\) whereas Trial B only reaches 40 mmol \(kg^{-1}\) after 24 hours).
- Award [1] for identifying that the rate is highest in the first 2 hours of recovery in Trial A compared to a slow, continuous flat rate in Trial B.

(b) [2 marks total]
- Award [1] for explaining that carbohydrate consumption increases blood glucose levels, triggering the secretion of insulin from the pancreas.
- Award [1] for explaining that insulin increases glucose uptake (via GLUT4 translocation) and/or activates the glycogen synthase enzyme within skeletal muscle cells.

(c) [2 marks total]
- Award [1] for recommending protein intake to promote muscle repair and synthesis.
- Award [1] for recommending water/electrolyte (sodium) intake to assist in rapid rehydration and fluid retention.

(a) 1. Closed: The skill is self-paced and performed in a stable, predictable environment where the performer dictates when to begin. 2. Gross: The movement requires the contraction of large muscle groups (legs, core, shoulders) to generate the necessary force. 3. Discrete: The serve is a single, brief skill that has a clear, distinct beginning (releasing the ball/swing start) and end (ball contact/follow-through).

(b) A learner in the cognitive stage is focused on understanding 'what' needs to be done. Performance is characterized by high variability, a large frequency of errors, and a lack of fluidity or coordination. The learner cannot self-correct because they lack an established internal feel (kinesthesis) for the skill, relying heavily on explicit instructions, external feedback, and visual modeling (demonstrations).

(c) Distributed practice: The coach structures the practice session with frequent rest intervals or inserts different light tasks between serving practices. This is useful for beginners as it prevents physical fatigue and mental overload, keeping attention high. Blocked practice: The coach has the beginners perform the underhand serve repeatedly in a single block (e.g., executing 15 serves consecutively) before changing tasks. This repetition is ideal for beginners to develop muscle memory and establish consistent basic motor programs.

(a) [3 marks total]
- Award [1] for classifying as closed and giving a valid reason (stable/predictable environment, self-paced).
- Award [1] for classifying as gross and giving a valid reason (involves large muscle groups/whole-body movement).
- Award [1] for classifying as discrete and giving a valid reason (has a clear, distinct beginning and end).

(b) [2 marks total]
- Award [1] for identifying that performance is highly inconsistent, lacks fluidity, and contains many errors.
- Award [1] for explaining that the learner relies heavily on visual cues/demonstrations and external feedback because their internal kinesthetic feel is not yet developed.

(c) [2 marks total]
- Award [1] for explaining how distributed practice prevents fatigue or maintains concentration by spacing practice with rest periods.
- Award [1] for explaining how blocked practice uses high repetition of a single skill to consolidate the basic motor program.

(a) Tidal volume is the volume of air inhaled or exhaled with each single breath during quiet or active breathing. Ventilation is the total volume of air moved into and out of the lungs in one minute, calculated as tidal volume multiplied by breathing frequency (\(V_E = V_T \times f\)).

(b) At rest, ventilation is maintained at a low, stable rate (typically 6-8 L \(min^{-1}\)). During submaximal exercise, ventilation increases linearly with exercise intensity/oxygen consumption to ensure adequate gas exchange. This is achieved by increases in both tidal volume and breathing frequency. At maximal/near-maximal exercise, ventilation increases non-linearly (at the ventilatory threshold) relative to workload. This disproportionate rise is driven by a dramatic increase in breathing frequency to expel carbon dioxide and manage blood acidosis.

(c) During high-intensity exercise, anaerobic metabolism produces lactic acid, which dissociates into hydrogen ions (\(H^+\)), lowering blood pH. Concurrently, metabolic rate increases, raising the partial pressure of carbon dioxide (\(PCO_2\)). Chemoreceptors (central chemoreceptors in the medulla and peripheral chemoreceptors in the carotid and aortic bodies) detect this increase in acidity and \(PCO_2\). They transmit neural signals to the respiratory control center in the medulla oblongata, which stimulates the respiratory muscles to contract more rapidly and deeply, elevating ventilation to eliminate \(CO_2\) and normalize pH.

(a) [2 marks total]
- Award [1] for defining tidal volume as the volume of air breathed in/out per single breath.
- Award [1] for defining ventilation as the volume of air breathed in/out per minute (or stating the formula \(V_E = V_T \times f\)).

(b) [3 marks total]
- Award [1] for describing resting ventilation (low and stable, approx. 6-8 L \(min^{-1}\)).
- Award [1] for describing submaximal exercise (linear increase with workload/intensity to meet metabolic demands).
- Award [1] for describing maximal exercise (disproportionate/non-linear increase, reaching the ventilatory threshold, driven heavily by increased breathing frequency).

(c) [2 marks total]
- Award [1] for explaining that chemoreceptors detect rises in blood/cerebrospinal fluid \(PCO_2\) and hydrogen ions (\(H^+\)) / decrease in pH.
- Award [1] for explaining that chemoreceptors stimulate the respiratory control center in the medulla to increase the depth and frequency of breathing.

(a) Agonist muscle: Biceps brachii (contracts concentrically to generate force). Antagonist muscle: Triceps brachii (relaxes/lengthens to allow movement). Joint action: Elbow flexion (decreasing the angle at the elbow joint).

(b) Once calcium ions are released from the sarcoplasmic reticulum into the sarcoplasm, they bind to troponin. This binding causes a conformational change that pulls tropomyosin away from the active binding sites on the actin filament, exposing them. Myosin heads, which are energized by prior ATP hydrolysis, bind to these exposed active sites on the actin filament to form cross-bridges. The release of ADP and inorganic phosphate (Pi) triggers the power stroke, during which the myosin head pivots and pulls the actin filament toward the center of the sarcomere (M-line), shortening the H-zone and sarcomere. A new molecule of ATP then binds to the myosin head, causing it to detach from actin. Finally, ATP is hydrolyzed by myosin ATPase into ADP and Pi, releasing energy that re-cocks the myosin head to its high-energy position, ready to repeat the cycle.

(a) [3 marks total]
- Award [1] for identifying agonist as the biceps brachii.
- Award [1] for identifying antagonist as the triceps brachii.
- Award [1] for identifying joint action as elbow flexion.

(b) [4 marks total]
- Award [1] for stating that calcium binds to troponin, causing a shape change that shifts tropomyosin and exposes active binding sites on actin.
- Award [1] for explaining that myosin heads bind to actin to form cross-bridges.
- Award [1] for describing the power stroke where the myosin head pivots, releasing ADP/Pi and pulling the actin filament toward the center of the sarcomere (M-line).
- Award [1] for explaining the role of ATP binding (causing myosin to detach from actin) and ATP hydrolysis (providing energy to re-cock the myosin head).

(a) Cardiovascular drift is characterized by a gradual, progressive increase in heart rate and a corresponding decrease in stroke volume during prolonged, submaximal steady-state exercise, even though the external workload/power output remains completely constant.

(b) To cope with the elevated environmental temperature, blood is shunted to the skin (cutaneous vasodilation) to facilitate heat dissipation via the evaporation of sweat. This pooling of blood in the cutaneous circulation, combined with fluid loss from sweating (which reduces overall blood plasma volume), decreases venous return to the heart. This reduces end-diastolic volume and decreases stroke volume (via Starling's Law of the Heart). Since cardiac output must be maintained to sustain the constant 200W workload (\(Q = \text{HR} \times \text{SV}\)), the heart rate must progressively rise to compensate for the falling stroke volume.

(c) 1. Maintain a regular hydration schedule before and during the ride by consuming fluids with added electrolytes (particularly sodium) to help maintain blood plasma volume. 2. Implement active cooling interventions, such as using a strong convective fan in the laboratory, spraying water on the skin, or consuming ice-slurry beverages to attenuate the rise in core temperature and minimize skin blood flow requirements.

(a) [2 marks total]
- Award [1] for describing a progressive decline in stroke volume during prolonged, steady-state exercise.
- Award [1] for describing the parallel/compensatory progressive increase in heart rate.

(b) [3 marks total]
- Award [1] for explaining that cutaneous vasodilation (blood shunted to the skin for cooling) and/or sweat-induced dehydration reduces plasma volume/venous return.
- Award [1] for linking decreased venous return/plasma volume to a lower stroke volume.
- Award [1] for explaining that heart rate must increase to maintain a constant cardiac output (\(Q = \text{HR} \times \text{SV}\)).

(c) [2 marks total]
- Award [1] for advising drinking fluids with sodium/electrolytes during exercise to preserve plasma volume.
- Award [1] for advising external cooling techniques (such as using fans, wearing cooling garments, or consuming iced drinks) to reduce thermal strain and cutaneous blood flow.

(a) Mechanics of ventilation during high-intensity exercise:
During high-intensity exercise, ventilation must increase significantly to meet the oxygen demands of active muscles and remove carbon dioxide. Both inspiration and expiration become active processes:
- Inspiration: The diaphragm and external intercostal muscles contract more forcefully. Additional accessory muscles are recruited, including the sternocleidomastoid, scalenes, and pectoralis minor. These muscles lift the ribs and sternum further upward and outward, dramatically increasing the thoracic volume and creating a larger pressure drop (greater negative pressure) inside the lungs, drawing in more air (increased tidal volume).
- Expiration: While passive at rest, expiration becomes active during high-intensity exercise. The internal intercostal muscles contract, pulling the ribs downward and inward. Additionally, the abdominal muscles (rectus abdominis, obliques, transversus abdominis) contract forcefully, pushing the diaphragm upward. This rapidly decreases thoracic volume, creating a high positive pressure in the lungs that expels air quickly, facilitating a faster breathing frequency.

(b) Explanation of cardiovascular drift:
Cardiovascular drift is characterized by a gradual, progressive increase in heart rate (HR) and a corresponding decrease in stroke volume (SV) during prolonged, steady-state, submaximal exercise, particularly in warm environments, while cardiac output (CO) remains relatively constant.
- Thermoregulation & Sweating: To dissipate heat generated during prolonged exercise in a warm environment, the body increases sweat rate and diverts blood to the skin (vasodilation).
- Plasma Volume Reduction: Sweating leads to progressive fluid loss from the blood plasma, reducing total blood volume.
- Decreased Venous Return: The reduction in plasma volume and redistribution of blood to the skin reduces the volume of blood returning to the heart (venous return).
- Decreased Stroke Volume: Reduced venous return decreases end-diastolic volume (EDV) / preload, resulting in a reduced stroke volume (via the Frank-Starling mechanism).
- Heart Rate Compensation: Because cardiac output must be maintained to meet the metabolic demands of the working muscles (\(\text{Cardiac Output (CO)} = \text{Heart Rate (HR)} \times \text{Stroke Volume (SV)}\)), the heart rate must increase to compensate for the falling stroke volume.

(c) Physiological adaptations of the cardiovascular and respiratory systems to long-term aerobic endurance training:
Cardiovascular Adaptations:
- Cardiac Hypertrophy: Specifically, eccentric hypertrophy characterized by an increase in left ventricular chamber size/volume, which allows for greater diastolic filling.
- Increased Stroke Volume: Due to larger left ventricular volume, increased myocardial contractility, and increased blood volume. SV increases at rest, during submaximal, and maximal exercise.
- Resting and Submaximal Bradycardia: A decrease in resting and submaximal heart rate due to increased stroke volume and increased parasympathetic (vagal) tone.
- Increased Maximal Cardiac Output: Due to the dramatic increase in maximal stroke volume, even though maximal heart rate remains unchanged or decreases slightly.
- Increased Blood Volume: Increase in blood plasma volume and red blood cell count, improving overall oxygen-carrying capacity and venous return.
- Capillarization of Skeletal Muscle: Increased capillary density around slow-twitch muscle fibers, improving oxygen and nutrient delivery, and waste removal.
- Lower Blood Pressure: Especially during submaximal exercise, due to reduced peripheral vascular resistance.

Respiratory Adaptations:
- Increased Maximal Minute Ventilation (\(\text{V}_E\)): Peak ventilation increases during maximal exercise due to improvements in both tidal volume and respiratory rate.
- Improved Ventilation Efficiency: At submaximal workloads, oxygen cost of ventilation is reduced, meaning less energy is spent by respiratory muscles.
- Increased Pulmonary Diffusion Capacity: Enhanced diffusion of oxygen from alveoli to blood and carbon dioxide from blood to alveoli at maximal exercise, facilitated by increased alveolar capillary surface area.
- Increased Strength and Endurance of Respiratory Muscles: Diaphragm and intercostal muscles become more fatigue-resistant.

(a) Mechanics of ventilation during high-intensity exercise [5 marks max]:
- Award 1 mark for stating that both inspiration and expiration become active processes (compared to passive expiration at rest).
- Award up to 2 marks for explaining inspiration: Diaphragm and external intercostals contract more forcefully [1 mark]; recruitment of accessory muscles (sternocleidomastoid/scalenes/pectoralis minor) further increases thoracic volume and decreases intrapulmonary pressure [1 mark].
- Award up to 2 marks for explaining expiration: Active contraction of internal intercostals pulls ribs down/in [1 mark]; active contraction of abdominal muscles forces diaphragm upward, rapidly decreasing thoracic volume and increasing intrapulmonary pressure [1 mark].

(b) Cardiovascular drift [7 marks max]:
- Award 1 mark for defining cardiovascular drift (increase in HR, decrease in SV over time at a constant work rate).
- Award 1 mark for stating that Cardiac Output (CO) remains relatively constant.
- Award 1 mark for mentioning the equation: \(\text{CO} = \text{HR} \times \text{SV}\).
- Award 1 mark for linking prolonged exercise/heat to increased sweating and skin blood flow (thermoregulation).
- Award 1 mark for explaining that sweating reduces blood plasma volume.
- Award 1 mark for linking reduced plasma volume to decreased venous return / end-diastolic volume (preload).
- Award 1 mark for explaining that reduced venous return leads to a reduction in stroke volume (Frank-Starling law).
- Award 1 mark for concluding that HR must rise to compensate for the decrease in SV to maintain CO.

(c) Physiological adaptations to aerobic training [8 marks max]:
Award 1 mark per distinct point up to 8 marks. Must cover both systems for maximum marks (max 6 marks if only cardiovascular or only respiratory adaptations are discussed).
Cardiovascular (Max 5 marks):
- Left ventricular hypertrophy / increased chamber size [1].
- Increased stroke volume (at rest, submax, and max) [1].
- Decreased resting and submaximal heart rate (bradycardia) [1].
- Increased maximal cardiac output [1].
- Increased capillary density/capillarization in skeletal muscles [1].
- Increased blood volume / plasma volume / red blood cell count [1].
Respiratory (Max 4 marks):
- Increased maximal minute ventilation (\(\text{V}_E\)) [1].
- Improved ventilation efficiency at submaximal levels (lower oxygen cost of breathing) [1].
- Increased pulmonary diffusion capacity (at maximal exercise) due to increased capillary network around alveoli [1].
- Increased strength/endurance of respiratory muscles (diaphragm/intercostals) [1].

(a) Application of Newton's Laws of Motion to a sprinter:
- Newton's First Law (Law of Inertia): States that an object will remain at rest or in uniform motion unless acted upon by an external force. The sprinter remains stationary in the blocks (inertia of rest) until they actively generate a muscular force. This force overcomes their inertia, causing them to change their state of motion and start accelerating.
- Newton's Second Law (Law of Acceleration): States that the rate of change of momentum (or acceleration) of a body is directly proportional to the force applied and takes place in the direction of the force (\(F = ma\)). A sprinter with a given mass (\(m\)) will accelerate (\(a\)) faster out of the blocks if they can exert a greater force (\(F\)) against the blocks. The direction of acceleration is the same as the direction of the net external force.
- Newton's Third Law (Law of Action-Reaction): States that for every action, there is an equal and opposite reaction. The sprinter exerts a force backwards and downwards onto the starting blocks (action force). Simultaneously, the starting blocks exert an equal and opposite force forwards and upwards onto the sprinter's feet (reaction force/ground reaction force), which propels the sprinter forward.

(b) Biomechanical factors affecting the trajectory of a projectile:
- Speed of release (projection speed): This is the most critical factor determining the horizontal distance (range) and peak height of the projectile. A higher release speed increases the initial kinetic energy, allowing the projectile to travel further and stay in the air longer.
- Angle of release (projection angle): The angle relative to the horizontal at which the object is released. Theoretically, in a vacuum with equal release and landing heights, the optimal angle for maximum distance is \(45^\circ\). In sports like shot put, the release height is higher than the landing height, making the optimal angle of release lower than \(45^\circ\) (typically \(35^\circ - 42^\circ\)).
- Height of release (projection height): The vertical height above the ground at which the object is released. A greater release height increases the time the projectile spends in the air (flight time), which increases the total horizontal distance traveled, assuming other factors are constant.
- Aerodynamic factors (Air resistance/Wind/Lift/Drag): For aerodynamic projectiles like a javelin or discus, lift forces can keep the object airborne longer, and drag forces will slow it down. The Magnus effect (spin) can also alter the flight path of spinning projectiles, though it is less significant for a heavy shot put.

(c) Manipulation of moment of inertia and angular velocity in gymnastics:
- Definition of Angular Momentum (\(L\)): The quantity of rotation of a body, defined as the product of its moment of inertia (\(I\)) and its angular velocity (\(\omega\)), expressed as \(L = I\omega\).
- Law of Conservation of Angular Momentum: Once the gymnast leaves the ground (in flight), there are no external torques acting on them (neglecting air resistance). Therefore, their total angular momentum (\(L\)) must remain constant throughout the flight.
- Definition of Moment of Inertia (\(I\)): A body's resistance to angular acceleration/rotation, which depends on the body's mass (\(m\)) and the distribution of that mass relative to the axis of rotation (\(I = \sum mr^2\)).
- Initiating/Increasing Spin (Tucking): To rotate faster (increase angular velocity, \(\omega\)), the gymnast pulls their limbs close to their body (tuck position). This decreases the radius (\(r\)) of mass distribution from the axis of rotation, which significantly reduces the moment of inertia (\(I\)). Since \(L\) is conserved and must remain constant, the angular velocity (\(\omega\)) must increase, causing them to spin faster.
- Slowing Down for Landing (Opening up): To prepare for a controlled landing (decrease angular velocity, \(\omega\)), the gymnast extends their body (layout position). This increases the radius of mass distribution from the axis of rotation, increasing the moment of inertia (\(I\)). Since \(L\) is conserved and must remain constant, the angular velocity (\(\omega\)) decreases, slowing down the rotation.

(a) Application of Newton's Laws [6 marks max]:
- Award up to 2 marks for Newton's First Law: Define/explain inertia / state of rest [1 mark]; link to the sprinter requiring muscle force to overcome inertia and move out of the blocks [1 mark].
- Award up to 2 marks for Newton's Second Law: State \(F=ma\) or define the law [1 mark]; link to how a greater force applied by the sprinter results in a greater acceleration out of the blocks (for a given mass) [1 mark].
- Award up to 2 marks for Newton's Third Law: State "action-reaction" concept [1 mark]; explain that the sprinter pushes back/down on the blocks (action) and the blocks push the sprinter forward/up (reaction) [1 mark].

(b) Factors affecting projectile trajectory [6 marks max]:
- Award up to 2 marks for Speed of Release: Identify it as the most critical factor [1 mark]; explain that higher speed increases distance/height/flight time [1 mark].
- Award up to 2 marks for Angle of Release: Identify its role [1 mark]; explain that the optimal angle is \(45^\circ\) if landing and release heights are equal, or lower than \(45^\circ\) (e.g., \(35^\circ - 42^\circ\)) when release height is higher than landing height [1 mark].
- Award up to 2 marks for Height of Release: Identify its role [1 mark]; explain that higher release height increases flight time, resulting in greater distance [1 mark].
- Award up to 1 mark for mentioning Aerodynamic factors (drag, lift, wind, or Magnus effect/spin) affecting the trajectory (especially for javelin) [1 mark].

(c) Manipulation of moment of inertia [8 marks max]:
- Award 1 mark for the formula/relationship of angular momentum: \(L = I\omega\) (where \(L\) is angular momentum, \(I\) is moment of inertia, \(\omega\) is angular velocity).
- Award 1 mark for explaining the Law of Conservation of Angular Momentum (angular momentum remains constant when in flight/no external torque).
- Award 1 mark for defining moment of inertia as resistance to rotation/determined by mass distribution relative to the axis (\(I = \sum mr^2\)).
- Award up to 2 marks for explaining how to increase rotation speed: Gymnast tucks/pulls limbs in [1 mark], which decreases the radius of mass distribution, decreasing the moment of inertia (\(I\)), thereby increasing angular velocity (\(\omega\)) to conserve \(L\) [1 mark].
- Award up to 2 marks for explaining how to slow down rotation: Gymnast extends/opens body into a layout [1 mark], which increases the radius of mass distribution, increasing the moment of inertia (\(I\)), thereby decreasing angular velocity (\(\omega\)) to conserve \(L\) [1 mark].
- Award 1 mark for linking the controlled decrease in angular velocity directly to preparing for a safe/stable landing.

(a) (i) The difference is calculated as: \(78.5 - 55.4 = 23.1\) points.
(ii) Both Group A and Group B experienced a slight decline in performance from the post-test to the retention test. Group A's mean accuracy decreased by 2.3 points (from 78.5 to 76.2), while Group B's mean accuracy fell by 3.7 points (from 62.1 to 58.4). Despite these decreases, both groups maintained higher accuracy than their initial pre-test baselines.
(iii) PETTLEP imagery (Group A) is significantly more effective than relaxation training (Group B) at improving penalty-kick accuracy, showing a post-test improvement of 26.2 points compared to only 10.3 points for relaxation. Furthermore, PETTLEP imagery demonstrates superior skill retention, with performance remaining highly stable at Week 12 (only a 2.3 point drop), whereas the relaxation group showed a faster decay in performance (3.7 point drop) when the intervention ceased.

(b) Practical application of PETTLEP components:
- Physical: The athlete should stand in their active soccer posture, wear their competitive kit (jersey, shorts, shin guards, cleats), and hold/place the actual match ball. This ensures the physical sensations of the imagery mirror the physical state of the motor execution.
- Environment: The player should perform the imagery while standing on the actual soccer pitch, facing the real goals with net and goalkeeper if possible, or use high-quality multisensory cues (grass smell, outdoor temperature, field sounds) to match the performance context.
- Timing: The imagined preparation, run-up, and strike of the ball must take place in real-time speed. The imagined action should not be slowed down or sped up, so that the neural pathways activated correspond directly to the temporal demands of the physical movement.

(c) Distinction and effects:
- Cognitive anxiety represents the mental/thought-based symptoms of anxiety, such as worry, negative thoughts, fear of failure, and poor concentration. High cognitive anxiety can distract the athlete, cause 'paralysis by analysis', and lead to a catastrophic drop in performance if physiological arousal becomes too high.
- Somatic anxiety represents the physical/physiological manifestation of anxiety, such as elevated heart rate, muscle tension, sweating, and rapid breathing. While extreme somatic anxiety can cause mechanical stiffness and muscle tremors, moderate somatic levels can be interpreted positively as 'readiness' or excitement if cognitive anxiety remains low.

(d) Applying Achievement Goal Theory to create a mastery (task-oriented) climate:
- Tasks: Coaches should design tasks focusing on individual skill development, personal improvement, and variety. For example, setting personalized targets for ball-striking technique rather than scoring percentage.
- Authority: Coaches can involve players in the decision-making process, such as choosing their own target placement or selecting which drills to run, supporting their autonomy.
- Recognition: Recognition and rewards should be based on personal progress, effort, and persistence rather than public social comparisons or win-loss records.
- Grouping: Players should be placed in mixed-ability, collaborative small groups that emphasize peer coaching and cooperation rather than constant peer competition.
- Evaluation: Evaluations must be multi-dimensional, confidential, and focused on personal development and task mastery rather than public ranking.
- Timing: Allow flexible timelines for athletes to master skills, recognizing that learning rates differ.

(a) (i)
- 1 mark for correct math: 23.1 (or 23.1 points).

(a) (ii)
- 1 mark: Noting that both groups showed a decline in accuracy from post-test to retention test.
- 1 mark: Quantifying the change for at least one group (e.g., Group A decreased by 2.3 points / Group B decreased by 3.7 points) OR stating that Group A's performance remained more stable/retained better than Group B.

(a) (iii)
- 1 mark: Deducing that PETTLEP imagery is significantly more effective for accuracy improvement than relaxation training.
- 1 mark: Deducing that both interventions are more effective than physical practice alone (control).
- 1 mark: Stating that PETTLEP leads to superior long-term retention of accuracy compared to relaxation.

(b)
- Award up to 2 marks per component (Physical, Environment, Timing):
- 1 mark for describing the theoretical focus of the component.
- 1 mark for providing a realistic, soccer-specific practical application.
- Accept equivalent detailed examples matching the PETTLEP framework.

(c)
- 1 mark: Defining cognitive anxiety as the cognitive/mind-based thoughts/worries.
- 1 mark: Defining somatic anxiety as the physical/body-based physiological responses.
- 2 marks: Explaining the effect of cognitive anxiety on performance (e.g., loss of concentration, distraction, relationship to catastrophic failure).
- 2 marks: Explaining the effect of somatic anxiety on performance (e.g., physical stiffness, muscle tension disrupting flow, potential positive interpretation under low cognitive anxiety).

(d)
- Award up to 7 marks for discussing achievement goal theory and motivational climate:
- 1-2 marks for defining the difference between task/mastery orientation (personal improvement) and ego/performance orientation (beating others).
- 1 mark for linking task-orientation to higher intrinsic motivation / self-determination.
- 3-4 marks for concrete application of the TARGET model categories (Tasks, Authority, Recognition, Grouping, Evaluation, Timing) to construct a mastery climate. Award 1 mark per distinct, well-applied strategy.

(a) (i) The difference is calculated as: \(72\% - 48\% = 24\%\).
(ii) For both strategies, muscle glycogen depletion increases progressively over the 120-minute time trial. However, Strategy B (30 g/hr single source) shows a significantly steeper rate of glycogen depletion at every interval compared to Strategy A (90 g/hr multi-transportable), resulting in a much higher final depletion level (89% vs 62%).
(iii) Glucose relies on the sodium-glucose co-transporter 1 (SGLT-1) transport proteins in the intestinal lumen, which saturate at approximately 60 g/hour. Fructose, on the other hand, is absorbed via GLUT-5 transport proteins, which are independent of SGLT-1. In Strategy A, using a combination of both glucose and fructose prevents the saturation of SGLT-1, allowing absorption to reach up to 90 g/hour. This delivers more exogenous glucose to the active muscles, providing alternative fuel and reducing reliance on endogenous muscle glycogen.

(b) Evaluation of carbohydrate loading:
- Carbohydrate loading aims to supercompensate muscle glycogen stores to delay fatigue during endurance events lasting longer than 90 minutes.
- Classic Astrand Protocol: Involves a 3-4 day glycogen depletion phase (heavy exercise + low carbohydrate intake) followed by a 3-4 day loading phase (rest + high carbohydrate intake). While extremely effective at maximizing glycogen stores, the depletion phase causes severe fatigue, irritability, immune suppression, and increases injury risk.
- Modified Protocol: Eliminates the depletion phase; involves a gradual exercise taper over 6 days with a simultaneous high carbohydrate intake (approx. 70-80% of daily caloric intake) during the final 3 days. It is safer, highly tolerated, avoids psychological distress, and achieves comparable glycogen supercompensation without physical breakdown.

(c) Physiological consequences of dehydration:
- Dehydration leads to a reduction in plasma volume and total blood volume.
- This reduced blood volume lowers venous return, decreasing end-diastolic volume and stroke volume (SV).
- To maintain cardiac output (\(\text{Q} = \text{HR} \times \text{SV}\)), heart rate (HR) must increase progressively, causing high cardiovascular drift and cardiovascular strain.
- To conserve core fluids, sweat rate decreases and cutaneous blood flow is restricted (peripheral vasoconstriction).
- This severely impairs the body's primary heat-dissipating mechanism (evaporation) in hot, humid conditions.
- Core temperature increases rapidly, accelerating central nervous system fatigue and elevating the risk of heat exhaustion or heat stroke.

(d) Metabolic and physiological roles of vitamins:
- Fat-soluble vitamins (absorbed with lipids, stored in adipose tissue and liver):
- Vitamin A: Crucial for retinal health/vision, plays an essential role in tissue growth and maintaining a robust immune system to defend against illness.
- Vitamin D: Crucial for bone health as it regulates calcium and phosphorus absorption; also supports skeletal muscle contractile function, muscle protein synthesis, and immune modulation.
- Water-soluble vitamins (dissolve in water, not stored in the body, excess excreted in urine):
- Vitamin C: Acts as a powerful antioxidant that neutralizes free radicals/oxidative stress induced by high-intensity training; essential for the synthesis of collagen for joint and tendon repair, and assists in non-heme iron absorption.
- B-Complex Vitamins (e.g., Thiamine, Riboflavin, Niacin, Cobalamin): Essential coenzymes in energy production pathways (glycolysis, Krebs cycle, electron transport chain). Cobalamin (B12) is vital for red blood cell production (erythropoiesis), optimizing oxygen transport.

(a) (i)
- 1 mark: 24% (or 24 percentage points).

(a) (ii)
- 1 mark: Recognizing that both strategies show a continuous/progressive increase in muscle glycogen depletion over time.
- 1 mark: Stating that Strategy B results in faster and overall higher glycogen depletion compared to Strategy A.

(a) (iii)
- 1 mark: Explaining that glucose uses SGLT-1 transporters, which saturate at around 60 g/hr.
- 1 mark: Explaining that fructose uses GLUT-5 transporters, which do not compete with glucose for absorption.
- 1 mark: Linking the dual-transport pathways to higher total absorption and exogenous oxidation rates, sparing endogenous glycogen.

(b)
- Award up to 6 marks:
- 1 mark: Stating the primary objective of glycogen loading (supercompensating muscle glycogen to delay depletion/fatigue).
- 1 mark: Describing the Classic Astrand protocol (depletion phase followed by loading phase).
- 1 mark: Explaining limitations of the Classic protocol (fatigue, mood swings, injury risk, gastrointestinal distress).
- 1 mark: Describing the Modified protocol (exercise tapering + high carbohydrate diet without depletion).
- 1 mark: Explaining advantages of the Modified protocol (reduced physical/mental stress, lower risk of injury, easier compliance).
- 1 mark: Stating that both successfully increase glycogen storage, but modified is generally preferred for athlete well-being.

(c)
- Award up to 6 marks for outlining physiological mechanisms:
- 1 mark: Reduction in blood plasma volume.
- 1 mark: Decrease in venous return and stroke volume.
- 1 mark: Compensatory increase in heart rate / cardiovascular drift to maintain cardiac output.
- 1 mark: Reduced sweat rate / impaired heat dissipation via evaporation.
- 1 mark: Decreased skin blood flow to conserve core volume.
- 1 mark: Rapid rise in core temperature / thermal strain / risk of heat injuries.

(d)
- Award up to 7 marks (maximum of 4 marks for either group of vitamins):
- 1 mark: General distinction of fat-soluble vitamins (stored in lipid tissue/liver) vs water-soluble vitamins (not stored, excreted).
- 1 mark: Role of Vitamin A (vision, immune support, cell growth).
- 1-2 marks: Role of Vitamin D (calcium absorption, bone mineralization, muscle remodeling/function).
- 1 mark: Role of Vitamin C (antioxidant defense, collagen synthesis, iron absorption).
- 1-2 marks: Role of B-complex vitamins (essential coenzymes in macronutrient metabolism / ATP production and/or red blood cell production).