Steve has been interpreted as superhuman by ed brubaker. His own interpretation of "peak of human potential" has spread like wildfire and become comic law in the mind of some.
With that being said, according to original intent and normal potrayal, Cap is not superhuman.
This is where some would say "but then why does he do all those things that humans cant actual do on a consistent basis Namorsubby".....while theres actually a simple explanation for that. Its because whats humanly posssible in comicbooks has never ever been a reality in.....well, reality. Name any grade a well known human superhero fromany comic company who doesnt perform some "superhuman" feat every issue. If caps a meta, batmans a meta. Nightwing too. Might as well add punisher, elektra, etc etc etc. They all do what we cant in real life.