Adjective
lung-busting (comparative more lung-busting, superlative most lung-busting)
(colloquial) exhausting, causing someone to be out of breath.
If all that sounds like a little bit too much, the Scenic Sportive is also spectacular without being quite so lung-busting. Source: Internet
Burning 800 calories an hour for a typical man, it would take more than four lung-busting 90 minutes of 11-a-side football to exercise off the Christmas bulge. Source: Internet