Describe how cardiovascular drift occurs during a marathon.

Outline the process of the sliding filament theory after calcium has been released and until it is pumped back into the sarcoplasmic recticulum.

Analyse how rehearsal and organization improve memory in a sporting routine.

Evaluate two fitness tests used to assess body composition.

is an increase in HR during prolonged exercise ✔

blood volume is reduced through sweating
OR
increased blood viscosity

therefore causing a reduction in venous return ✔

stroke volume is directly affected by venous return
OR
reduction in stroke volume/SV ✔

HR × SV = Q/ cardiac output is the product of HR times SV ✔

the compensation takes place to help maintain cardiac output during exercise ✔

exercise in a hot environment exaggerates cardiovascular drift
OR
dehydration contributes to cardiovascular drift ✔

as blood is redirected to the skin to help temperature regulation ✔

Ca²⁺ binds with troponin ✔

tropomyosin are lifted from the actin filament binding sites ✔

myosin heads attach to actin to form a cross bridge ✔

heads of myosin tilt and drag the actin filaments, referred to as the power stroke ✔

cross bridge breaks as ATP splits ✔

Z lines move closer together
OR
H zone disappears ✔

ratchet mechanism continues until the ends of the myosin filaments reach the ends of the Z lines ✔

Rehearsal:
by practising the sequence as much as possible they can become overlearned ✔

this means that they become automatic and therefore effective in establishing a memory trace ✔

however this requires time and may not be accessible to the performer ✔

therefore other methods such as mental rehearsal may be required ✔

Organization:
the sequence can be organized in meaningful ways to help learn and remember them more easily ✔

for example ensuring that the movements are practised in sequence so the end of one movement is followed by the start of one movement ✔

verbalizing the routine as it is organized may also assist the learner to memorize the routine ✔

organization of the routine still requires rehearsal and therefore in isolation may not be the only method ✔

Award [3 max] per method.

BMI (body mass index):
Body mass index is a measure of an adult’s weight in relation to height/weight in kg divided by their height in metres squared ✔

Strengths:
more accurate than standard height and weight tables ✔

easy to administer ✔

non invasive ✔

Limitations:
BMI is not a direct measure of body fat ✔

not suitable for certain populations eg, children, pregnant women, elderly or athletes ✔

despite its inaccuracy it is still used as a medical standard to assess obesity ✔

 

Anthropometry:
most common field technique is skinfold calipers ✔

where skin fat thickness is measured at a number of sites and the sum of these sites used in an equation estimates percentage body fat ✔

Strengths:
accuracy is greater than BMI ✔

more detailed protocol and equations are used to focus on gender specific differences ✔

widely used due to its accessibility ✔

limited cost implications ✔

non-invasive ✔

Limitations:
reliability of the data is affected by the experience and consistency of the tester ✔

accuracy is affected by the number of sites and the calculation being used to determine density ✔

equations are based mostly on cadaver studies ✔

 

Underwater weighing/Hydrostatic weighing:
the athlete is weighed totally immersed in water OR where the difference between their scale weight and underwater weight is measured ✔

Strengths:
considered one of the most accurate measures of body composition ✔

perhaps considered the most reliable and valid ✔

Limitations:
major weakness is in the conversion of body density to estimate relative body fat ✔

equation assumes that fat mass and fat-free mass is constant in all people ✔

specialized equipment ✔

high cost ✔

 

Award [3 max] per test.

At least one strength and one limitation per test. Accept other suitable examples of strengths and limitations.

This was one of the best responses to this type of question and candidates were clearly well prepared for this type of question.

Many candidates were well prepared for this question and answered it very well; however, several candidates wrote much more than was required for a 4-mark question wasting valuable time that could have been used elsewhere. Candidates were able to describe the sequence of events accurately, but some responses lacked specificity of the steps that were required to earn full marks.

Overall, this question was typically answered very poorly. Candidates struggled to provide enough detail to achieve full mark points. Answers were not focused and candidates did not appear to be prepared for this question.

Overall, this question was answered well. Some candidates struggled to identify the correct fitness tests, confused tests, or described the mechanics of the tests rather than evaluated them.