Get an adjustable 0-90 bench
Grab a light pair of DBs, something you can solidly do 10-12 reps with
Set the bench to flat, perform 1 set to failure
15 degrees, 1 set to failure
Repeat this for 30, 45, 90 degrees, and then...
90, to 45, to 30, 15, to flat
It adds to 10 sets, all to failure
Same weight all sets
How is this a prison workout?
I picked it up from Jailhouse Strong by Josh Bryant
Some prisoners, the weight yard DBs only when to 75lbs....
Doing sets to failure at each angle, & then back down, it was a way to make light weights feel heavy
For hypertrophy and strength endurance, its fantastic