1. AIS Chap 5 Anaerobic capacity

2. Anaerobic power and anaerobic capacity
Anaerobic power 無氧動力: Peak rate of ATP produced via anaerobic metabolism, difficult to measure directly
Usually estimated from peak power output during all-out sprint-type exercise
Anaerobic capacity 無氧能力: Maximal amount of ATP that can be generated through anaerobic metabolism, during short-duration maximal ex
Important for m running, m freestyle swimming, 1-4 km track cycling, 2000 m rowing, m kayaking, team sports

3. Measure anaerobic ATP production
Muscle biopsy 肌肉穿刺: Changes in muscle metabolites
Blood lactate after supramaximal exercise
Oxygen debt 氧債 after supramaximal exercise
Total work or mean power output during short-duration maximal exercise
Wingate test (30 s all-our cycling), 9-40% ATP produced aerobically
Tests < 60 s inadequate to exhaust anaerobic system
Accumulated oxygen deficit

4. Rest-to-Exercise Transitions
Oxygen uptake increases rapidly
Reaches steady state within 1-4 minutes
Oxygen deficit
Lag in oxygen uptake at the beginning of exercise
Suggests anaerobic pathways contribute to most ATP production
After steady state is reached, ATP requirement is met through aerobic ATP production

5. The Oxygen Deficit

6. Differences in VO2 Between Trained and Untrained Subjects

7. accumulated oxygen deficit
At submaximal exercise: O2 consumption meets energy demand at steady state, aerobic metabolism
Linear VO2-power output relationship
Supramaximal exercise: required ATP from aerobic + anaerobic metabolism
Exercise performed at a power output higher than that achieved at VO2peak
<60 sec sprint, or 2-4 min at constant power output
Accumulated oxygen deficit = calculated accumulated oxygen demand – measured accumulated oxygen demand
MAOD: maximally accumulated oxygen deficit
Valid and reliable measurement for anaerobic capacity

8. Assumption and criteria for MAOD as good estimation for anaerobic capacity
Mechanical efficiency identical in supra- and submaximal exercise
the rate of total energy release (i.e. O2 demand) increases linearly with the exercise intensity
O2 demand is constant during this type of supramaximal exercise
Leveling off with exercise duration
Increased with duration of exhaustive exercise until level off
Independent of maximal oxygen uptake (VO2max)

9. Procedures VO2 – power output relationship
Originally 10 stages at 10 min per stage
Modified to fewer stages at 40-70% VO2max with 4 min per stage
Duration of performance test
Long enough to allow max anaerobic energy release
Short enough to minimize aerobic energy production
Constant power output % peak VO2
Or ‘all-out’ for a specific duration or distance

10. Oxygen stores of body
In transition from rest to exercise, mouth VO2 underestimate tissue VO2
O2 bind to hemoglobin and myoglobin
O2 dissolved in body fluids
O2 in lungs
Estimated 9% oxygen deficit
Should be subtracted from absolute MAOD

11. Maximal accumulated oxygen deficit (MAOD)
Medbo JI, 1988

12. Accumulated oxygen deficit vs duration of supramaximal exercise
Medbo JI, 1988

13. Relative accumulated oxygen deficit
Medbo JI, 1988

14. MAOD range
38 ml/kg in middle distance trained athletes, to 100 ml/kg in sprint trained athletes
60 kg: 2.3 L O2eq – 6 L O2eq
MAOD unaffected by inspired O2 concentration
Independent of aerobic metabolism

16. Oxygen Deficit and Debt During Light-Moderate and Heavy Exercise

17. Recovery From Exercise: Metabolic Responses
Oxygen debt
Elevated VO2 for several minutes immediately following exercise
Excess post-exercise oxygen consumption (EPOC)
“Fast” portion of O2 debt
Resynthesis of stored PC
Replacing muscle and blood O2 stores
“Slow” portion of O2 debt
Elevated body temperature and catecholamines
Conversion of lactic acid to glucose (gluconeogenesis)醣質新生