Exercise Physiology and Human Performance
What this domain tests
This domain checks whether you can turn bioenergetics and cardiorespiratory physiology into safe, individualised training prescription for athletes and active patients - not just recite definitions.
Core rules and concepts
- Energy systems sit on a continuum: phosphagen (ATP-PCr) dominates roughly 0–10 s, glycolysis roughly 10 s–2 min, oxidative phosphorylation thereafter. Specificity follows the system you overload.
- VO2max equals cardiac output (HR × SV) multiplied by the arteriovenous oxygen difference. A valid graded test needs a VO2 plateau, RER ≥1.10, and HR within about 10 bpm of measured maximum.
- Lactate thresholds: ~2 mmol/L is the first breakpoint; ~4 mmol/L approximates onset of blood lactate accumulation. Maximal lactate steady state is the highest intensity at which lactate stays stable.
- Training principles: overload, specificity, reversibility, individuality, recovery. A taper usually cuts volume 40–60% for 1–2 weeks while retaining intensity.
- Cardiovascular drift: heart rate rises at a fixed workload in heat as plasma volume falls, so HR alone misrepresents intensity.
Worked example
A 30-year-old runner has measured HRmax 190 bpm and resting HR 60. Karvonen for a 70% session: target = 60 + 0.70(190 − 60) = 60 + 91 = 151 bpm. Reasoning: Karvonen scales heart rate reserve, so 70% of the working range is prescribed; a naive 70% of 190 (133 bpm) would be a materially easier session and would not produce the intended adaptive stimulus.
Traps that cost marks
- Treating 220 − age as a measured maximum instead of an estimate with large individual error.
- Confusing RER with RQ, or assuming maximal fat oxidation always occurs at low intensity.
- Reading session heart rate without accounting for heat, dehydration, or caffeine.