Maximal oxygen uptake, also known as VO2max, is a crucial parameter for high endurance performance. It represents the maximum amount of oxygen that the body can consume and therefore describes the size of the “engine.” VO2max is typically measured in milliliters per minute (l/min) and adjusted to body weight (ml/min/kg).
The composition of VO2max is determined by the formula VO2max = stroke volume (SV) x heart rate (HR) x arteriovenous oxygen difference (avO2diff). Stroke volume refers to the amount of blood ejected from the heart with each beat, while heart rate represents the frequency of heartbeats per minute. Arteriovenous oxygen difference describes the difference between the amount of oxygen transported via arterial blood to muscle cells and the amount returned to the lungs via the venous system. A higher avO2diff indicates greater oxygen extraction by the muscles, which results in more oxygen being available for energy production.
VO2max is achieved when all of these systems are fully engaged, and the working muscles have access to the maximum amount of oxygen. It is a measure of aerobic performance and is applicable to all endurance sports, with higher values indicating greater aerobic capacity. Improving aerobic capacity leads to better lactate clearance and utilization, thereby increasing the anaerobic threshold and overall endurance performance. Understanding and monitoring VO2max is essential for individualized training zone determination and training progress evaluation.