I smoke too much, drink too much, eat too much etc etc.
Did a medical last year, not my usual Doc, but his fitness/healthy lifestyle son (nice guy btw) Had to do the peak flow thingy in a red plastic gadget. I blew it to the end of its range - don't know the value. The Doc looked at me speachless.
I put it down to the smoking induced coughing - gives me an extra strong diaphragm?