What are these?

[runner2000]

After seeing this picture on another post, I have just have to ask what these circled muscles are. I know most lean guys have them but they are so pronounced here.

 

[NBS 4life]

Its not so much a group of muscles

It is refered to as the adonis belt or appolos belt. Its pretty much a result of the formation of muscles around and bone structure (e.g. Insertion points etc)

You need good genetics and low bodyfat

 

[i_love_muscle]

NBS hit the nail on the head with that one

That's the iliac furrow (the iliac muscle has its origin from the iliac fossa, with insertion to the tendon of the psoas muscle, the anterior surface of the lesser trochanter, and the capsule of the hip joint, with nerve supply from the lumbar plexus, and whose action flexes the thigh and rotates it medially).

Leg raises might help but you would have to rotate your hip out ...

 

[Acein91]

Ahhh, I used to have very pronounced.. whatever those are.. back when I just did tons of running and no lifting.

Basically meaning that it's possible for those "muscles" to be well-defined just from having a low BF%