Unit 3: Physical Activity Participation and Physiological Performance
What you must understand
Unit 3 focuses on the physiological responses to physical activity and the factors affecting participation. Candidates must understand acute responses to exercise (heart rate, stroke volume, cardiac output, ventilation, blood flow redistribution, body temperature) and chronic adaptations from training (cardiac hypertrophy, increased capillary density, improved oxygen extraction, muscle hypertrophy). You must know the components of fitness (health- and skill-related), fitness testing principles (validity, reliability, specificity), and training principles (overload, progression, specificity, reversibility, recovery, individuality). Also understand participation patterns and the social-ecological model.
Traps to watch
A common trap is confusing acute responses (during or immediately after exercise) with chronic adaptations (long-term training changes). Do not describe increased resting stroke volume as an acute response. Another trap is mixing validity (measures what it claims) with reliability (consistent results). Students also forget that overload must be applied with progression to avoid injury. Avoid overgeneralising participation data; use trends cautiously.
Rule of thumb and worked example
Use the FITT principle (Frequency, Intensity, Time, Type) to design or evaluate a training program. Worked example: to improve aerobic capacity, apply overload by increasing frequency from three to four sessions per week, or intensity via target heart rate zones, while allowing recovery. Justify each change against the training principle it satisfies.
Exam skill
When comparing responses and adaptations, state the timeframe (acute versus chronic) and the mechanism. Use data from tables to support conclusions.