the abdominal muscles
The gluteal muscle.
The major spine flexor is the rectus abdominis muscle. It runs along the front of the abdomen and helps to bend the spine forward. It is commonly known as the "abs" muscle and is important for activities like sit-ups and crunches.
your gluts, abs, and your intogalactibal muscle.
Pretty much only abs, if you're doing them correctly. If you're doing it wrong, tights and arms might be worked too.
ur abs
sartorius
Because you sit on it everyday!
Rectus abdominus Internal and external obliques Transversus abdominus.
Technically speaking it's the abs. The agonist muscle in a situp is actually the hip flexors.
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.