1. Initiation of exercise
- When we exercise, the tendency for our muscles is to work harder, which utilizes more oxygen and thus, produces more carbon dioxide. With this, our breathing needs to increase from approximately 15 times a minute when we are resting up to around 40-60 times a minute when exercising to meet the demands of our bodies.
2. Moderate exercise
- Our muscles and the heart work harder when we exercise to burn more calories and more oxygen is needed to do the process. And as the level of activity increases, our respiratory rate increases as well to bring more oxygen into the lungs that will be pumped into our blood and out to our muscles.
3. Abrupt ascent into high altitudes
- When experiencing an abrupt ascent into high altitudes, we breathe faster and deeper, which is called hyperventilation–necessary for us to survive. Our lungs expose blood to fresh air and the increase in respiratory rate increases the flow of fresh air past the blood, which means that as each oxygen molecule is taken away by the blood, they will be replaced by a fresh one immediately.
4. Paralysis of phrenic nerve
- When the phrenic nerve is paralyzed, a patient experiences weakening of the diaphragm and reducing of breathing capabilities and being unable to control voluntary breathing. This is due to the phrenic nerve’s weak signaling to the diaphragm to relax or contract, or even unable to send any signal part of or the entire diaphragm.
5. Severe anemia
- Anemia occurs when there is a decrease in the level of hemoglobin compared to normal. It causes reduced capacity for blood to provide organs with oxygen and thus, the body needs to compensate for this by working harder to meet the same requirements such as increasing the breathing or heart rate.
6. Advanced pregnancy
- Since there is an increased body mass, the total body oxygen demand will increase as well by approximately 21%; and there will be an increase in the ventilatory requirements to clear the excess carbon dioxide. And thus, during labor, the oxygen consumption will increase by approximately 60%.
References:
Department of Health & Human Services. (n.d.). Anaemia. Better Health Channel. https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/anaemia#:~:text=A%20decreased%20level%20of%20haemoglobin,breathing%20rate%20or%20heart%20rate.
Diaphragmatic weakness & paralysis. (n.d.). Columbia Surgery. https://columbiasurgery.org/conditions-and-treatments/diaphragmatic-weakness-paralysis#:~:text=Patients%20with%20a%20paralyzed%20diaphragm,exhale%20outside%20air%20as%20efficiently.
High Altitude | APEX | Altitude.org. (n.d.). altitude.org. https://www.altitude.org/high-altitude#:~:text=BREATHING%20AT%20HIGH%20ALTITUDE,fresh%20air%20past%20the%20blood.
Why does your breathing rate increase when you exercise? (n.d.). https://www.cliffsnotes.com/cliffsnotes/subjects/sciences/why-does-your-breathing-rate-increase-when-you-exercise#google_vignette
Yartsev, A. (n.d.). Respiratory changes during pregnancy. Deranged Physiology. https://derangedphysiology.com/main/required-reading/pregnancy-obstetrics-and-gynaecology/Chapter%20114/respiratory-changes-during-pregnancy
Your lungs and exercise. (2016). Breathe, 12(1), 97–100. https://doi.org/10.1183/20734735.elf121