The women gathered inside a roped-off area at Newark Liberty International Airport. United Airlines staffers, all of them women, handed out bag tags and boarding passes. When a man approached the counter and presented his I.D. to check in for a flight, he was politely turned away. “Sorry,” a United employee said. “This is a special event.”

Marie Claire magazine’s Power Trip, now in its fourth year, is a business conference for women. It's also an endurance exercise. Over the course of 36 hours, maybe five of which are allotted for sleep, 200 entrepreneurs, executives and investors fly cross-country to meet, collaborate and throw money at each other’s ideas.

This networking sprint is invitation-only and all expenses paid. There’s also, naturally, tons of free stuff from corporate sponsors. In October, about a week before takeoff, each attendee received a Tumi carry-on suitcase filled with stuff they might like to have but probably didn’t need, including a pair of rugged-soled boots, regenerative nighttime serum and dry shampoo.

By most measures, the women invited to this event had already made it. They’d built and bolstered brands in technology, retail, food, finance, fashion and media. They had staffs to oversee, orders to fulfill, emails to send, calls to make, meetings to take, not to mention personal lives. And before they got to the airport, they didn’t know who would be joining them.