Rectus abdominus Internal and external obliques Transversus abdominus.
The gluteal muscle.
your gluts, abs, and your intogalactibal muscle.
well, your biceps longus is the muscle on the top of your thigh. You engage this muscle when you lift it while in the sitting position. the , once the leg is crossed, it is gravity that keeps your leg in place. ( I think :) )
ur abs
sartorius
Technically speaking it's the abs. The agonist muscle in a situp is actually the hip flexors.
Because you sit on it everyday!
the abdominal muscles
erector spinae for spinal extension and quadratus lumborum for spinal abduction
A sit up is an eccentric muscle contraction.
you can do lots of sit ups, it will strengthen your back and abdominal muscle!
It stops your muscle flow.