Is there any difference in difficulty between the 15m and 20m bleep test? I understand that the legnth of time between the bleeps on the former is reduced to take into account the fact that you are running 5m less between each bleep, and that this is designed to compensate for the fact that the distance is shorter. My gym offers the former of these as we have limited space, the PT who does it says that there is no difference in the final result and that all things being equal this will convert into the same when I go and run the 20m. Can anyone confirm this, and if it is not true what do I need to do to convert a score from the 15m test into an approx. score on the 20m test?