The heart rate oximeter – a measure of blood oxygen saturation – drops when you start exercising but should return to normal as your breathing rate increases. Learn more about oxygen levels after exercise.
Your oxygen saturation measurements during exercise vary depending on your health and exercise intensity.
How do the oxygen levels change during exercise?
Your oxygen levels are likely to drop when you first start a workout because, by changing various properties in your blood, physical activity reduces the amount of oxygen that can bind to hemoglobin.
Your body adapts to different oxygenation levels during physical activity by increasing your breathing rate. As the breathing rate increases, the oxygen level in the blood may increase. However, your body quickly raises oxygen levels.
Your breathing will be strained, and you will probably not continue if you do not get enough oxygen during exercise.
Does the oxygen level in the blood fall during exercise?
Yes. Oxygen saturation in the blood only drops during exercise as the body works to meet the demands of working muscles, according to a study from the 2013 Australian Journal of Basic and Applied Sciences.
If there is a question of a person’s oxygen saturation during exercise, another measurement form may be necessary. An arterial blood gas test can provide accurate information about moving oxygenation levels.
In some cases, hypoxemia is caused by heart problems or defects or lung diseases such as bronchitis, asthma, or emphysema. Low oxygen levels can also be a side effect of some medications or sleep apnea.
Seek medical attention if you experience frequent symptoms of hypoxemia during exercise or rest.