@qrp, I'm sorry to hear of your physical challenges. Believe me, I can relate. Having part of your lung removed is major surgery, and it's not unusual to have long-term side effects. Several things could contribute to your shortness of breath, even beyond the fact that you've lost 20% of your lung capacity! My first question would be, "What is your follow-up treatment?" For example, if you're on Tagrisso for an EGFR mutation, then Tagrisso is also lowering your red blood cell count.

I had the same procedure six years ago. The best thing that I've found to help is deep breathing exercises. Your doctor probably encouraged you to do them after surgery but don't stop. My Spirometer is still on my nightstand, and I try to beat my last maximum at least three times a week. Of course, I don't, but the benefit is in trying.

My surgeon told me that, over time, the other two lobes will expand to fill the void left by the missing upper right lobe. Another doctor told me it can be up to two years before you start noticing. And I do know one woman who returned to running long distances. She doesn't do marathons anymore but still does 5Ks and half marathons.

Best of luck with your continuing recovery. I don't think it ever ends. Recovery is a process, not a place.

I had wedge resections done to both RUL and LUL and I have always noticed a shortness of breath when I bend over. If I am getting ready to go somewhere, which involves lots of small motions including bending over, I notice especially.
I suspect the lungs are compressed when bending over ...someone posted something once about it...and how a few extra pounds around the middle doesn't help. I have multiple causes for shortness of breath which incude lung cancer and pulmonary fibrosis.