TGUs in a WOD

Strength: Back Squat
5 reps @ 40% (65#)
5 reps @ 50% (75#)
3 reps @ 60% (90#)
3 reps @ 70% (105#)
3 reps @ 80% (120#)
3+ reps @ 90% (135#): 6 reps

Metcon: 10 min AMRAP
20 jumping lunges / 2 TGUs (12kg KB. Rx was 16kg KB)
7 + 20 lunges

Post: None

Failed on the 7th rep for the BS. Last week, I got 13 at 125#. I suppose my muscles are feeling taxed.
First time ever doing TGUs in a WOD. My left shoulder was too weak to even hold the 16kg KB so I resorted to the 12kg. That wasn't even the hard part. Had to break up the lunges into 4s or 5s starting in the third round.