Exercise Physiology and Biomechanics
What this domain tests
Exercise Physiology and Biomechanics tests acute responses to exercise, energy systems, training principles, and mechanical reasoning. Expect questions on cardiac output, lactate threshold, the force-velocity relationship, levers, and stability.
Core rules and concepts
- Acute responses: heart rate, stroke volume, cardiac output, ventilation, and oxygen uptake rise; systolic blood pressure rises while diastolic changes little; blood flow shifts to working muscle; heat production increases.
- Bioenergetics: ATP-PCr supports brief maximal efforts (about 0–10 s); glycolysis supports short high-intensity work; oxidative phosphorylation dominates longer, lower-intensity work.
- EPOC is excess post-exercise oxygen consumption; it is not the same as lactate removal, and lactate is a fuel and a marker, not the direct cause of delayed-onset soreness.
- Training principles: overload, specificity, reversibility, individualization, recovery. FITT-VP stands for frequency, intensity, time, type, volume, and progression.
- Biomechanics: torque = force × perpendicular moment arm; most human joints act as third-class levers; concentric force falls as velocity rises, while eccentric actions can tolerate more force; stability improves when the center of gravity is over a larger base of support.
- Length-tension: muscles produce the most active force near resting length; too much or too little overlap reduces force.
Worked example
A 30-year-old cycles at a steady 150 W. Heart rate rises from 65 to 140 beats/min in three minutes, stroke volume rises, and cardiac output increases. After several minutes, heart rate plateaus: this is a steady state. If power is increased above the lactate threshold, ventilation and perceived effort rise disproportionately because hydrogen ion accumulation and bicarbonate buffering increase CO2 drive. If the client then lifts a light load very quickly, force output is lower than with a heavy load moved slowly because of the force-velocity relationship.
Traps that cost marks
Do not equate heart rate with cardiac output; do not blame lactate for DOMS; do not apply a program for endurance to a strength goal; do not call eccentric action 'negative work' without explaining force; and do not assume static stretching before training prevents injury.