measures of energy expenditure

Question 1

what can measuring energy tell you

Answer 1

• gives an indication of the intensity of exercise
• used to identify levels of fitness
• highlight dietary requirements needed for performer to recover and replace energy
• provide feedback on effectiveness of training programme

Question 2

explain indirect calorimetry

Answer 2

technique that provides an accurate estimate of energy expenditure through gas exchange

• measures how much C02 produced and how much 02 is consumed at both rest and during aerobic exercise
• calculating gas volumes enables us to find the main substrate being used (fat or carb)
• reliable
• precise calculation of V02 and V02 max

Question 3

define calorimetry

Answer 3

• calculation of heat in physical changes and chemical reactions

Question 4

define indirect calorimetry

Answer 4

measures production of C02 and or consumption of 02

Question 5

how does lactate sampling work

Answer 5

involves taking a tiny blood sample and a hand held device analyses the blood and indicates how much lactate is present

Question 6

pros of lactate sampling

Answer 6

accurate and objective

Question 7

reasons for lactate sampling

Answer 7

• measures exercise intensity
• the higher the exercise intensity at which lactate threshold occurs the fitter the athlete is
• able to select relevant training zone to get desired training effect
• regular lactate testing provides a comparison to see if improvement has occurred. If lower lactate level at same intensity = increased speed/power, improved recovery heart rate and higher lactate threshold.

Question 8

which V02 max tests are more effective

Answer 8

multistage fitness test and cooper run only give prediction of V02 max
direct gas analysis is done is a labrotory and can produce much more reliable and valid result.

Question 9

multi-stage fitness test

Answer 9

= 20m progressive shuttle run to a bleep until you reach complete exhaustion.
- level reached is compared to a standard results table

Question 10

direct gas analysis

Answer 10

• run on treadmill to exhaustion while the air that is expired is calculated by computer software.
• Volume and concentration of oxygen in expired air is measured and compared with the % of oxygen in air to see how much oxygen has been used

Question 11

respiratory exchange ratio [RER]

Answer 11

= ratio of C02 produced compared to 02 consumed and used as a measure of exercise intensity

• provides info about fuel usage during exercise
• energy sources such as carbs, fats and proteins can all be oxidised to provide energy. For a certain volume of oxygen the energy released will depend upon the energy source
• calculating RER will determine which one of these energy sources is being oxidised therefore whether performer is working aerobically or anaerobically
• attached to a gas analyser while on treadmill or cycle ergometer so accurate readings

Question 12

calculation for RER

Answer 12

C02 expired per minute (VC02) / 02 consumed per minute (v02)

Question 13

RER close to 1 =
RER approx 0.7 =
RER greater than 1 =

Answer 13

RER close to 1 = performer using carbs
RER approx 0.7 = performer using fats
RER greater than 1 = anaerobic respiration so more C02 produced than 02 consumed

• higher % of body fat = lower RER

Question 14

what are the measures of expenditure

Answer 14

indirect calorimetry
lactate sampling
V02 max test
respiratory exchange ratio