Economy And Efficiency

Question 1

What is efficiency?

Answer 1

A measure of effective work

Energy out/energy in x 100 =% efficiency

Question 2

How could you measure efficiency?

Answer 2

Metabolic cart - uses direct or indirect calorimetry whilst measuring power output

Question 3

Whats the difference between direct and indirect calorimetry?

Answer 3

Direct- measure heat produced directly,

Indirect - measures heat via O2 consumption, CO2 production and H2 balance

Question 4

How do you calculate rate of EE?

Answer 4

Rate of EE (kcal/min) =VO2 (L/min) x calorific equivalent (kcal/L)

Question 5

What will a more efficient athlete be able to achieve?

Answer 5

At a given metabolic rate they will be able to produce more power and produce a given power output at a lower metabolic rate

Question 6

Name some determinants of efficiency

Answer 6

Cadence,
Muscle fibre type,
Muscle strength,
Flexibility,
Muscle-tendon stiffness,
Training,
Altitude and hypoxia

Question 7

What is net efficiency?

Answer 7

Gross efficiency - resting metabolic rate

Question 8

What is delta efficiency?

Answer 8

The change in energy expended relative to the change in actual work.
Mechanical power vs energy expended

Question 9

Whats one of the best determinant of endurance performance?

Answer 9

Delta efficiency

Question 10

If a person has a lower running VO2 for a given pace are they economic or efficient?

Answer 10

Economic

Question 11

If a person requires a smaller increase in VO2 during a change in running pace do they have better economy or efficiency?

Answer 11

Efficiency

Question 12

What is economy?

Answer 12

The energy cost per unit of power output or running speed