He promised “Fitness” and “Wellness” — and big bucks.

But the pitchman behind a purported health networking Web site was only improving his own financial fitness — by allegedly issuing $400,000 in bogus “stock.”

Mark Moore, 40, pleaded not guilty in Manhattan yesterday to charges he sat at his computer in his Morningside Heights apartment and ripped off more than 50 victims.

He allegedly did so by dubbing himself “CEO” of “eSprit, Inc.” and offering gullible marks the chance to invest in what Manhattan DA Robert Morgenthau yesterday called “a mere skeleton of a Web site,” which promised users would soon be able to engage in direct, online chats with massage therapists, dieticians and even a dance instructor.

Trouble was, the site never got built, the “stock” was worthless paper, the experts had never heard of him, and Moore blew almost all the money.