incline bench angle

[Ramstein II]

I'm not going to get into the clavical head (upper chest) versus sternal head (lower chest) debate but only to say that I personally can flex just my upper pecs or lower pecs which is enough evidence for me that I need to work my chest at different angles.

Now, I personally like low incline (25-30 degrees). But note: you must account for the arch in your back. You can arch your back enough on a 45 degree fixed incline to make it a 30 degree incline in execution--know what I mean? You can also stress the upper chest on a flat bench by taking the bar to your clavical--obviously be careful if you have tight shouldlers--but the point is you can make any angle of bench work if you find the groove.