Measurements of Energy Expenditure

Measurements of Energy Expenditure

1. Respiratory Exchange Ratio (RER)

   • Ratio of carbon dioxide produced to oxygen consumed
   • Provides information about fuel usage
   • RER = CO2 Expired per Min/O2 Consumed per Min
     • VCO2/VO2
     • Value close to 1 = carbohydrates as fuel
       • Value close to 0.7 = fats as fuel
         • Value >1 = working anaerobically, more CO2 produced than O2 consumed
   • Requires athlete to be attached to a gas analyser or cycle ergometer so accurate readings can be taken

2. VO2 Max Test

   • Bleep Test, Harvard Step Test, Cooper 12 min Run
   • Level that is reached can be compared to a chart
   • Sports lab can produce valid and reliable results using direct gas analysis
   • Increasing intensities on a treadmill, cycle ergometer or rowing machine
     • Tests on treadmill are accurate under lab conditions
       • Individual runs to exhaustion while air expired is calculated by a computer to see how much carbon dioxide is being expired and how much oxygen is being consumed

3. Lactate Sampling

   • Taking blood sample and a device analyses the blood & indicates how much lactate is present
   • Accurate, objective, qualitative data
   • Can give an idea of fitness levels
     • The higher the intensity at which lactate threshold occurs, the fitter the performer
   • Allows performer to select relevant training zones in order to get desired training effect
   • Regular lactate testing provides a comparison to see if improvements have been made

4. Indirect Calorimetry

   • Measures how much carbon dioxide is produced and how much oxygen is consumed during rest and aerobic exercise
   • Calculating gas volumes means we can find out the main energy source during activity (carbohydrates, fats, etc.)
   • Very reliable and accurate