I quitted smoking a few days ago and went back to boxing,i used to train it for like 2 years and it went smooth during trainings,but now i just gas out imidiately I want to improve my cardio What should i do to repair my lungs,increase lung capacity etc?
Continue to train, and continue not smoking. There isn't really specific advice for ex-smokers. Good news is your body can, to a limited extent, repair the damage. You'll start to feel the difference after the first four or five months clean. Otherwise, do like everyone else. Run, skip, spar. Good luck with it.
Train consistently and don't try to gain everything back at once. I think doing something five days a week is better than three large effort days, for example.
Rest assured after 2 weeks of non smoking your lungs will begin to heal, there' a time chart for it you should look up, keep up with training and give it time.
Like Giancomino said - Run, skip, spar - great advice. I smoke and have gone back to boxing as a strategy to reduce then quit smoking. The burning in the lungs from 'Run, skip, spar' replaces the burning of my lungs from smoking. I've halved the amount I smoke and WILL quit this year b/c of how much my cardio is holding me back. It's frustrating to be able to only execute my skills in sparring for a couple of rounds before having to revert to a style that involves less ring movement, lower punch output and more defence.