A group of students is designing an investigation into how different energy systems respond during a 45-minute aerobic training session that gradually increases in intensity. Evaluate various methods they could use to collect data on these physiological responses. (8 marks)
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Sample Answer
- Blood lactate sampling provides direct measurement of lactate accumulation indicating anaerobic glycolytic system contribution but requires specialised equipment and is invasive, limiting sampling frequency.
- Heart rate monitoring offers continuous data on cardiovascular demand throughout the session and can be correlated to energy system usage when combined with known individual maximum heart rate.
- Respiratory gas analysis measuring oxygen consumption and carbon dioxide production would provide the most comprehensive data on aerobic energy system contribution but requires expensive equipment not typically available to students.
- Rating of Perceived Exertion (RPE) offers subjective feedback on exercise intensity that correlates with energy system transitions but lacks the precision of physiological measurements.
- A combination approach using heart rate monitoring continuously with periodic RPE ratings and strategically timed lactate samples (if available) would provide multi-dimensional data on energy system transitions during increasing exercise intensity.
- Data collection should occur at rest, during defined intensity transition points, and during recovery to capture the full spectrum of physiological responses across energy systems.
- Standardisation of exercise protocol is essential when collecting data on energy system responses, with clearly defined intensity increments at set time intervals.
- The practical limitations of invasive methods must be weighed against the value of direct physiological measurements when selecting appropriate data collection methods for student investigations.
Show Worked Solution
Sample Answer
- Blood lactate sampling provides direct measurement of lactate accumulation indicating anaerobic glycolytic system contribution but requires specialised equipment and is invasive, limiting sampling frequency.
- Heart rate monitoring offers continuous data on cardiovascular demand throughout the session and can be correlated to energy system usage when combined with known individual maximum heart rate.
- Respiratory gas analysis measuring oxygen consumption and carbon dioxide production would provide the most comprehensive data on aerobic energy system contribution but requires expensive equipment not typically available to students.
- Rating of Perceived Exertion (RPE) offers subjective feedback on exercise intensity that correlates with energy system transitions but lacks the precision of physiological measurements.
- A combination approach using heart rate monitoring continuously with periodic RPE ratings and strategically timed lactate samples (if available) would provide multi-dimensional data on energy system transitions during increasing exercise intensity.
- Data collection should occur at rest, during defined intensity transition points, and during recovery to capture the full spectrum of physiological responses across energy systems.
- Standardisation of exercise protocol is essential when collecting data on energy system responses, with clearly defined intensity increments at set time intervals.
- The practical limitations of invasive methods must be weighed against the value of direct physiological measurements when selecting appropriate data collection methods for student investigations.