The exercise is focused on the deep stabilization system for side muscles. You will feel your waist and hips.
Single exercises: shoulders - rear
handles: upper pulley, seat: knees
If you attache handles from side to the seat you get a suspension straps and you can do the hardest rowing with XUP.
Rowing with single leg workout will strenghten your back, glut and hamstrings at the same time.
Rowing with XUP will help back pain and improve proper posture. You will active your back core and biceps as well.
The reverse peck deck greatly tone your rear delts and shoulder blades muscles.