Takes me about 17 breaths to fill it up all the way (I have the small sleeping pad). Just to make sure you know, this isn't a self-inflating pad.

While there's no way to pump them up, there is actually a little bit of a trick that I found. When you unscrew the valve you have to actually press it back in towards the pad to make sure all the air you're breathing goes into the pad itself. Keep it unscrewed, but press back towards the pad. Basically - while you're inflating the mattress, make sure you're not pulling the valve away from the mattress, or a lot of the air will escape before it even makes it into the mattress. I hope that makes sense, maybe I'll try to put some graphics to a picture and upload it later. I can inflate my regular pad in about 3 minutes without getting lightheaded.