W hen Kristian Gkolomeev woke up one morning in February, the last thing he expected to do was break a world record in the pool. The Greek swimmer and four-time Olympian, who finished fifth in the 50-m freestyle in Paris and Tokyo, had come to Greensboro, N.C., to take part in a preview of something called the Enhanced Games, a new start-up that plans to stage an Olympic-style competition permitting the use of most performance-enhancing drugs (PEDs) currently banned in global sports.