Puffing and panting goes with exercise, and is to be expected. The usual measure is that you should still be able to talk while exercising. If breathing is getting harder work, one possible cause could be something missing in your diet.
When we exercise, our muscles demand more oxygen and produce more carbon dioxide. That triggers our lungs to work harder to bring in the oxygen and expel the carbon dioxide. The heart also pumps faster so that the blood can get this oxygen to the muscle cells.
Vitamin B12 is essential for humans, and has two main functions. It is needed for nerve cells, and also to make the red cells in blood. These cells take oxygen to the muscles and transport carbon dioxide back to the lungs for expulsion. Red blood cells only live for around four months and so need constant replacement.
A lack of B12 can mean that the body does not make enough red blood cells, or the ones that it does make are too large and don’t transport gases efficiently. The lungs see this as a need to try harder.
There is a standard blood test to check B12 levels. However it cannot differentiate between ‘active’ and ‘inactive’ B12 forms, and it is the active form that is needed for good health. Hence diagnosis is not always straightforward and may need specialist work.
B12 comes from meat, fish and dairy sources, so those on a varied diet should have no problem getting sufficient B12. Vegans cannot get B12 from natural sources, so should ensure that their food is fortified with B12 and consider taking a daily supplement.
Hopefully a tweak or two to your diet will do the trick - but if you are still out of breath, get checked out.
Jim I had never heard that before about unwashed vegetables being a source of B12. That's really interesting, but as you say it's not something we'd want to do nowadays.
Michael isn't wrong, B12 is essential for humans. Our ancestors either ate meat or ate vegetables that, er, hadn't been washed too well. That meant they were ingesting some animal products on the vegetables. It is just as well that we can now get supplements!
This is the one thing that makes me feel veganism isn't natural or good for us. What would our ancestors have done without supplements?