Explain how anaerobic energy systems could contribute to ATP production during a 3-minute round of boxing.

Describe long-term vascular adaptations to endurance training.

Describe the process of energy production and supply to brain cells.

Using examples, suggest ways a coach could manipulate task constraints in training.

all systems work concurrently / at all times ✔

dominant system is determined by intensity and duration / the anaerobic system will dominate due to the short duration «3 minutes» and high intensity of many of the actions «punching is explosive» ✔

ATP-CP:

dominant for the first 7–10 seconds ✔

system replenishes initially used ATP ✔

one ATP produced from one CP ✔

has a high rate but low yield ✔

during quieter phases in the round the system may be replenished to assist the seamless flow of ATP ✔

Lactic acid / anaerobic glycolysis:

dominant from five seconds to 1–2 minutes ✔

source of ATP is glucose molecule ✔

2–4 ATP produced from one glucose molecule ✔

bi-product of «hydrogen ions» / lactic acid inhibits effectiveness of ATP production ✔

Award [3 max] per energy system.

Award [5 max] if the explanation does not refer to the energy systems during boxing

[6 max]

increased capillarisation in lungs/ trained muscles ✔

blood plasma increases ✔

red blood cell count / hemoglobin increases ✔

more effective blood redistribution ✔

these factors result in increased arterio-venous oxygen difference (a-VO₂ difference) ✔

decreased resting blood pressure ✔

improved elasticity of blood vessels ✔

decreased resting heart rate ✔

increased stroke volume ✔

lower working heart rate when working at the same intensity as to prior to the training occurred ✔

Lower working HR needs to be clearly linked to when working at the same intensity as prior to training

[4 max]

glucose is the main fuel source «for energy production in the brain» ✔

glucose «and oxygen» cross the blood–brain barrier / are passed from the blood cells to the brain ✔

the process is aerobic respiration / using oxygen ✔

carbohydrate storage in the brain is limited ✔

«however» supply of glucose is continuous ✔

brain uses about half of all the sugar energy in the body ✔

[4 max]

modifying equipment available eg lighter, shorter-handle rackets ✔

setting relevant task goals eg must make three passes before scoring ✔

changing the time of game eg shortening time of half/quarter ✔

modifying the size of the playing area eg smaller to encourage tighter control / adapt for young children ✔

adapting playing area design eg attacking/defending zones/no go zones ✔

modifying the balance of the teams eg create overload to practice attacking or defending ✔

modifying team’s personnel eg moving better quality players to different team ✔

Award [1] max for a list of 3 or more task constraints with no examples.

[6 max]

Many candidates were able to explain anaerobic respiration stages well. Some students struggled to apply the concepts in boxing.

Many students were able to access at least 3 marks. Several students identified adaptations, which were not related to the vascular system.

Many candidates were able to describe that glucose, oxygen and aerobic glycolysis was part of the process.

Many candidates understood the three different types of constraints and were able to give some examples. Although many examples were repetitions or similar themes.