Why you're paying so much to exercise

Millennials are turning the fitness industry upside down

On a frigid Sunday this month, Rianka Dorsainvil, a 29-year-old financial planner outside Washington, D.C., found herself running up a steep, snowy hill wearing a 20-pound vest and dragging a 215-pound man behind her.
 
She was paying for the privilege. The man harnessed to her was her personal trainer, who runs a studio out of his home and micromanages not just Dorsainvil’s workouts but her meals, too. She calls him the “mad scientist”.
 
“It’s great to have an expert pushing you in the right direction,” she said.
 
A growing segment of the US population is making a