I appreciate that aircraft have different weights for similar models but let's take an 'average' 150/152 with reasonable avionics fit and the sort of weight increase that comes with time, say:
1150 lbs
Add full fuel at: 160 lbs
MAUW: 1600 lbs
This leaves: 290 lbs
Allow: 10 lbs for headsets/clothing etc
Leaves room for 280 pounds of crew (10 stone each!)
I would suggest that many 150/152 training sorties are flown with the aircraft above MAUW.