Just because on another post I saw TomWill ask about calculating VO2max from 2.4km run, you can also calculate a VO2max score from the MAS score
There is a more complicated formula but the difference is minimal so use:
VO2max (ml/kg/min) = 3.5 X final speed on MAS test
Therefore if your athlete has a MAS of 18 km/hr, their predicted
VO2max would be 63 ml/kg/min.
Cheers