Confirming Maximal Oxygen Uptake: Is Heart Rate the Answer?

Area of Science:

• Exercise Physiology
• Cardiovascular Physiology

Background:

• Determining maximal oxygen uptake (V̇O2max) is crucial for assessing aerobic fitness.
• Maximal heart rate (HRmax) is often used as a secondary measure to confirm V̇O2max attainment.
• Traditional methods for confirming V̇O2max can be time-consuming and may require verification phases.

Purpose of the Study:

• To investigate if a heart rate plateau (HRplat) can reliably confirm the attainment of V̇O2max in young adults.
• To compare the efficacy of HRplat with other secondary criteria for V̇O2max verification.

Main Methods:

• Eleven young adults (22.4±3.21 yr) underwent V̇O2max testing.
• Heart rate (HR) and V̇O2 were measured continuously.
• HRplat was defined as a change in HR ≤ 2 beats/min over the final 60s of sampling.
• V̇O2max was confirmed using established criteria and an independent verification phase.

Main Results:

• A HRplat (≤2 beats/min) was achieved by 91% of participants, with an average HR change of 1.3±1 beats/min.
• The timing of HRmax attainment coincided with V̇O2max achievement.
• Respiratory exchange ratio (RER) and ΔRER criteria were met significantly earlier than V̇O2max.
• Age-predicted maximal heart rate (HRage) was not reached by many participants.

Conclusions:

• A heart rate plateau (HRplat) ≤ 2 beats/min is a more accurate indicator of true V̇O2max achievement in this cohort than other secondary criteria.
• HRplat may reduce or eliminate the need for a separate verification phase in V̇O2max testing.
• This finding has implications for efficient and reliable assessment of maximal aerobic capacity.