Is a Sub 2:00 marathon possible? How long will it be until the latest record is broken? These are hard questions to answer and no one has a crystal ball, but the history and current performance data would suggest that the answers are, “yes” and “maybe a long time.”
The history would indicate that the record will continue to fall, but at a slower and slower rate. The data also seems to suggest that record falls steadily for a while and then plateaus for a while before falling again. We have been on a down slope for a few years, so the trend could flatten out and we could see no improvement for an extended time.
Scientists have concluded from their research that it should be humanly possible without genetic manipulation or drug use to run under 2:00. Most of this is based on VO2max and Lactate measurements over shorter distances though, and the marathon is not just twice as far as the half marathon.
So, how low can we go? Noboby knows.