Carbohydrates are important for muscular contraction during hill walking. Describe the role of insulin on glucose uptake when walking.

Discuss the structural differences between slow twitch and fast twitch muscle fibre types.

Analyse how research design and statistical analysis aid the validity of studies conducted by sports scientists.

Motor skills are classified into various continua. Using examples, outline the motor skills along the interaction continuum.

insulin is released from pancreas <beta cells> in response to elevated levels of blood glucose;

insulin promotes glycogenesis;

this process maintains blood glucose homeostasis;

if glycogen storage sites are full, insulin stores glucose as adipose tissue <through lipogenesis>;

during exercise insulin release is inhibited/ decreases due to the sympathetic nervous system operating;

exercise enhances transport of glucose across the cell membrane <due to glut-4 transporters>;

insulin enhances glycolysis which is useful when walking;

slow twitch fibres:
higher myoglobin content;

higher capillary density allows for increased oxygenation;

higher triglyceride storage;

lower glycogen storage;

higher mitochondrial density;

lower phosphocreatine stores;

smaller fibre diameter;

lower sarcoplasmic reticulum amounts;

Contrast for each function must be provided.

Accept in the converse for fast-twitch.

Do not accept colour.

use of dependent and independent variables demonstrate causality;

control groups ensure that changes observed are attributable solely to the intervention and not to any other factors;

placebos are inactive substances or conditions that should have no effect on the subject;

use of blind / double blind allocation prevents bias;

use of <inferential> statistics shows the significance of the findings / informs researcher whether or not to accept null hypothesis;

randomization guards against ordering/learned/fatigue effects;

design a method / use valid measuring tools that permit repetition and replication;

Award [3 max] if no reference to statistics.

individual:
performed in isolation;
e.g. running by yourself;

coactive:
performed at the same time as others but without direct confrontation;
e.g. running a race in your own lane (such as 100 m);

interactive:
performed where other performers are directly involved / space is shared / performance can be influenced by the opposition;
e.g. soccer game;

Award [1 max] for list of three elements within the continuum.

Award [3 max] if no examples given.

i.e. Note: [1] for description, [1] for example.

This is a complex question because role of insulin and exercise are different in how they impact on the movement of glucose, yet they do the same thing: encourage the movement of carbohydrate into a cell.

Candidates found it difficult to recall the "structural" differences of the two types of muscle fibre.

Candidates were generally able to show their understanding for the use of statistical analysis to get a mark. They struggled to gain the other marks for the study design features.

In general, candidates did well on this question; some became confused with the other types of continua such as "open versus closed".