answer:First, stretch it out by grabbing the ends and pulling it out to its full lenght a couple of times. This relaxes the latex so it won’t fight you so much. Then don’t try to start the inflation using your lung power. Your lungs are pretty limited in the amount of pressure they can generate. You want to just use the muscles in your lips, cheeks and jaw to get a mouthful of air in there to start with. You can get considerably more pressure that way. So you enclose as much air as you can with your mouth, close off the air passage back of your throat, and then compress all that air using all your mouth musculature, as if you were squirting a mouthful of water out of your lips. Once that first mouthful off air has begun opening up the balloon, your lungs can take it from there.