Julie Istvan feels at her best when she’s hanging upside down.
She’s been suspending herself that way for the better part of four years, ever since encountering the art of aerial silks on a yoga retreat in Costa Rica. Since then, she’s made a point of spider-climbing toward the nearest high ceiling on long sashes of cloth for, oh, roughly five hours a day.
It was basically the discovery of a long-desired career, Istvan says.
“I started taking classes, and…