Identify one effect on the immune system of training for a marathon.

Outline strategies a marathon runner could use to reduce the risk of infection.

Describe the extrinsic regulation of the sinoatrial (SA) node as an athlete begins a warm-up.

Describe two functions of the skin.

Suggest how an aerobic 1500 m endurance athlete uses the principles of overload.

Evaluate the multistage fitness test as a method of assessing aerobic capacity in a long-distance runner.

decrease in innate and adaptive immune functions✔

due to increases in levels of cortisol and adrenaline over long periods ✔

low concentrations of lymphocytes ✔

leucocytes may drop compared to sedentary individuals ✔

ensure that the athlete plans sufficient recovery within their training/avoid overtraining
OR
ensure that the athlete achieves sufficient sleep ✔

maintain a varied diet providing suitable vitamins and minerals
OR
ensure the athlete maintains fluid levels ✔

drink pathogen-free water
OR
maintain good food hygiene standards when preparing food ✔

athlete maintains good personal hygiene
OR
maintains oral hygiene ✔

minimize/avoid contact with infectious individuals ✔

do not train during illness ✔

Receptors: Sub Max [2]
chemoreceptors detect an increase in CO₂ ✔

baroreceptors detect an increase in blood pressure ✔

proprioceptors detect an increase in muscular movement ✔

Autonomic nervous system: Sub Max [2]
information is received by the <cardiovascular control centre in the> medulla oblongata ✔

the sympathetic nervous system < accelerator nerve > sends a signal to the SA node ✔

SA node increases firing to increase HR ✔

Regulation of body temperature:
production of sweat <helps evaporation> for heat loss ✔

hairs erect to trap air to reduce heat loss ✔

vasodilation of blood vessels to the skin to release heat
OR
vasoconstriction of blood vessels to the skin to conserve heat ✔

Protection and immunity:
a barrier to microorganisms ✔

a barrier to physical trauma ✔

reduces harmful effects of radiation ✔

Sensation:
contains nerves that relay information about the environment, such as heat, cold and sensing touch or pain ✔

Excretion:
waste material, such as urea / uric acid / water / ammonia through sweat ✔

Synthesis of vitamin D:
organic chemical within the skin reacts with UVB ultraviolet light to synthesize vitamin D ✔

overload is the increase of stress on the body during exercise training to bring about desired adaptations
OR
forcing the body to work harder/more intense/longer than normal ✔

frequency, intensity, time (type) are principles of overload ✔

as adaptation takes place, a further increase in training load is required to stimulate further increases ✔

Frequency:
eg 1500 m athlete could increase their frequency of training to 4 times a week instead of 3 ✔

Intensity:
eg 1500 m athlete could change from working at 70 % MHR to 75 % MHR ✔

eg include hill running rather than just road/track ✔

Time:
eg 1500 m athlete could run for 30 minutes instead of 25 minutes ✔

Strengths: Sub Max [3]
the test has validity/reliability for predicting VO₂ max/ assessing aerobic capacity✔

a number of participants can be assessed simultaneously ✔

relatively limited cost/equipment required ✔

relatively easy to administer ✔

Limitations: Sub Max [3]
due to the regular turning required it is more specific to games-based athletes✔

requires motivation of athletes to reach volitional exhaustion ✔

maximal test can place participants at risk ✔

administrators need to ensure cheating doesn’t occur/follow strict protocol ✔

not specific for long-distance runners ✔

MSFT score is converted to estimate VO₂ max
OR
not a direct measure of VO₂ max ✔