How to Calculate the Ventilatory Threshold

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The study of exercise physiology gives an insight into how your body reacts while working out. As exercise increases in intensity, the air flowing in and out of your respiratory tract, known as ventilation, progressively increases in a linear fashion. When this pattern deviates and becomes non-linear, the corresponding change is called ventilatory threshold. You can calculate your ventilatory threshold in a few steps if you have familiarity with formal exercise measurements and terms.

Review the components. Ventilatory threshold is derived from oxygen consumption and the amount of O2 extracted from the air by the lungs. Oxygen consumption (VO2) is dependent on the ability of the heart to pump out blood, the ability of the tissues to extract oxygen from the blood, the ability to ventilate, and the ability of the alveoli to extract oxygen from the air.

Identify the formula. Ventilatory threshold is calculated as VO2 divided by (.2093 minus FEO2); where (.2093 – FEO2) represents the amount of O2 extracted from the air by lungs.

Calculate Ventilatory Threshold. For example, where VO2 equals 3.5 mL/kg/min and FEO2 equals 16% of O2, compute VE as (3.5 mL/kg/min)/(.2903- .16) = 26.86 L/min. Most people have a VE of 6-10 L/min at rest and range between 100-170 L/min at maximum exercise rate.