Welcome to sport’s ultimate taboo where athletes risk it all for millions in Las Vegas

The Enhanced Games promise human advancement and world records but critics fear more worrying effects

On the eve of the most controversial sports event of the 21st century so far, one swimmer is explaining how it felt to take banned drugs for the first time. “I was anxious, to be honest,” says Andriy Govorov, the 50m butterfly world record-holder. “Because there’s no way back.”

The 34-year-old Ukrainian points to his backside. That is where the first needle carrying performance-enhancing drugs went into his body. Then to his stomach. That one hurt less. “I don’t like needles being stuck in me,” Govorov says. “When I was younger, I would pass out when I had blood tests.”