This article from the September 2012 issue of Breathe has been corrected and republished online according to the erratum originally published in the December 2012 print issue of Breathe.
Regrettably, there was a mistake on page 233 of the article as originally published. The following terms were incorrectly defined and should read as follows:
• Vital capacity (VC), the maximum amount of air that can be exhaled when blowing out at a steady rate.
• Peak expiratory flow (PEF), the maximal flow that can be exhaled when blowing out as fast as possible.