I am trying to return to running after a bout with viral pneumonia. All symptoms are gone except when exercising l feel like l only have a 1/4 of my oxygen. My lungs feel like they are not near full force. I don't have any phlegm, but they are still not feeling anywhere near normal in terms of running like my normal self. Today all l could manage was 4x 200 in 39 39,39,37, and 4x100s and It felt like l was moving in quicksand when I was running them, hence the reason l only did a few and some 100s. I know doing 200s at 10k pace isn't the best idea, but l am sick of huffing and puffing at an 8:45 pace or something for three miles. All this is very demoralizing, but l am just trying to do something, so when l do get better, l will be ready. Is it better to to strides of 100 to 200 everyday until l get better vs huffing and puffing 3 or 5 miles a day?