Evaluating maximal oxygen uptake in exercise-based cardiac rehabilitation

Area of Science:

• Cardiology
• Exercise Physiology
• Preventive Medicine

Background:

• Maximal oxygen uptake (VO2max) is a critical health and performance indicator, especially for individuals with heart disease, predicting mortality.
• Cardiopulmonary exercise testing is the gold standard for VO2max but is underutilized in primary healthcare.
• Cardiac rehabilitation programs can benefit from accessible VO2max assessment methods.

Purpose of the Study:

• To evaluate standard criteria for assessing VO2max in patients undergoing cardiac rehabilitation.
• To determine the suitability of VO2 plateau cut-offs in a primary healthcare setting.
• To identify reliable secondary criteria for confirming maximal effort during exercise testing.

Main Methods:

• A cross-sectional study involving 93 participants in a primary healthcare cardiac rehabilitation program.
• Cycle ergometer exercise tests were performed to determine VO2max.
• Primary validation used VO2 plateau cut-offs (≤50 and ≤100 mL O2/min); secondary criteria included respiratory exchange ratio (RER), rate of perceived exertion (RPE), and maximal heart rate.

Main Results:

• A VO2 plateau was achieved by 88% of participants using the ≤100 mL cut-off.
• 61% of participants met at least two secondary criteria, confirming maximal effort.
• The ≤100 mL cut-off demonstrated good utility in this population.

Conclusions:

• A VO2 plateau cut-off of ≤100 mL is a potentially suitable criterion for VO2max assessment in primary healthcare cardiac rehabilitation.
• When a plateau is not reached, RER ≥1.15 and RPE ≥17 can effectively indicate maximal effort.
• These findings support the integration of standardized VO2max testing in cardiac rehabilitation settings.