Accumulated Oxygen Deficit During Exercise to Exhaustion Determined at Different Supramaximal Work Rates

Area of Science:

• Exercise Physiology
• Sports Science
• Human Performance

Background:

• The accumulated oxygen deficit (AOD) is a key physiological indicator used to assess anaerobic energy system contributions during high-intensity exercise.
• Understanding the factors influencing AOD, such as exercise intensity and reliability, is crucial for accurate physiological assessment in athletes.

Purpose of the Study:

• To investigate the impact of supramaximal exercise intensities on the accumulated oxygen deficit (AOD) during constant work-rate cycling to exhaustion.
• To evaluate the test-retest reliability of AOD measurements obtained from these high-intensity cycling trials.

Main Methods:

• Twenty-one trained male cyclists and triathletes underwent incremental cycling tests to establish maximal oxygen uptake (V̇O₂max) and the V̇O₂-power output relationship.
• Participants completed square-wave cycling trials to exhaustion at various supramaximal intensities (105%, 112.5%, 120%, 127.5% V̇O₂max), with the 112.5% intensity performed twice for reliability assessment.

Main Results:

• Exercise intensity significantly affected AOD (P = .011), with values peaking at 112.5% and 120% V̇O₂max.
• AOD at 112.5% V̇O₂max was significantly higher than at 105% (P = .033) and 127.5% V̇O₂max (P = .022).
• The test-retest reliability for AOD at 112.5% V̇O₂max was high, with an intraclass correlation coefficient of .927 and a coefficient of variation of 8.72%.

Conclusions:

• The accumulated oxygen deficit, when measured during square-wave cycling to exhaustion, reaches its peak at exercise intensities between 112.5% and 120% of V̇O₂max.
• AOD measurement at 112.5% V̇O₂max demonstrates robust test-retest reliability, making it a dependable physiological marker.