While my experience is limited and this is not strain advice, I do want to say that after years of smoking cigarettes, I began experiencing the whole waking up in the middle of the night to gasp for air sensation (obviously quite a few of you know exactly what I'm talking about) but that's only part of the reason I eventually quit smoking. Anyways, I did quit smoking, went full blown vaper, and this issue has gone away entirely. My breathing isn't good, I wouldn't say, but it's not absolutely awful like it was and I no longer wake up in the middle of the night gasping for air. Vaping has quite literally made a world of difference for me. For reference, I do exercise daily by trekking miles through the woods or on the roads, making a point to run/jog here and there to get my lungs really going. This combination of exercise and switching from smoking to vaping has done wonders for me. Still not tip top shape here but I feel worlds better than I used to. That smoking will really kick your ass. Also, I am mainly referring to cigarettes, as I do still burn the occasional bowl or jay, but even that I've mostly given up in favor of vaping. Gotta have some really tasty nugs to rope me into a smoke sesh.