| Date | November 2018 | Marks available | 2 | Reference code | 18N.3.HL:.tz0.4 |
| Level | Higher Level | Paper | Paper 3 | Time zone | time zone 0 |
| Command term | Explain | Question number | 4 | Adapted from | N/A |
Question
Distinguish between the physiological effects of exercising at sea level with the effects of exercise at altitude within 24 hours of arrival.
Explain two long-term adaptations resulting from altitude training.
Markscheme
Blood adaptations:
increased number of red blood cells / viscosity to compensate for each carrying less oxygen at low oxygen levels ✔
smaller reduction in hemoglobin saturation ✔
excretion of base via the kidneys to restore acid-base balance ✔
Muscle adaptations:
reduced lean body mass ✔
increased capillary density, particularly in skeletal muscle to aid saturation ✔
increased mitochondrial density and enzyme concentration ✔
erythrpoietic response increases ✔
Cardiorespiratory adaptations:
increased pulmonary ventilation to compensate for vasoconstriction ✔
a decrease in maximum cardiac output a decreased maximum heart rate ✔
Accept other appropriate adaptions.
Adaptation must be explained for [1] mark.
Examiners report
This was difficult question for students, even though there were only 2 marks, many students did not distinguish between sea level and altitude and only gave one piece of information. The markscheme was also extensive with 14 mark points for only 2 marks.
