“Just being outside is a workout today,” Arianna Gaujean, 18, said while browsing the sale rack at Awoke Vintage in Greenpoint, Brooklyn. It was a scorching July evening and Ms. Gaujean, a student at St. Francis College, was wearing a short black racer-back dress — the ideal garment, she said, for doing just about anything in the heat.
In 35-and-under parlance, this was an “exercise dress,” an all-in-one outfit that, depending on your browsing habits, may be haunting your social feeds, with ads touting its comfort (stretchy nylon and spandex!), versatility (built-in shorts!) and universally flattering silhouette (who doesn’t feel