VO2 Max represents the maximum amount of oxygen that your body is able to utilize when you do strenuous exercise. It is the greatest indicator of your fitness as well as endurance. VO2 Max would typically be expressed in terms of milliliters of oxygen for each body weight in kilograms per minute (ml/kg/min). Your genetic makeup has a significant role to play in determining your VO2 Max, but you have the ability to enhance it through certain exercises.
An elevated VO2 Max enables athletes to work harder without fatiguing, which suits endurance sports such as cycling, running, and triathlon very well. Elite endurance athletes typically have VO2 Max levels in the 70s, 80s, or 90s, but amateur athletes have levels between 40 and 60. VO2 Max tends to rise through focused interval workouts, increases endurance, and frequent exercise. VO2 Max tends to be tested in a laboratory, but several fitness wearables now estimate VO2 Max through heart rate and performance data.