crazy health trend waist training

Illustration: David Wyffels

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Waist Training

The Idea: If you've been on Instagram in the past year, you've probably seen celebrities like the Kardashians snapping selfies in their waist trainers. These corset-like contraptions take a cue from Victorian times and claim to reshape your waist and kick-start fat loss in your stomach. You begin with 2-to-4-hour sessions and gradually build to round-the-clock wear.

The Problem: Makers of the garment say it strengthens your core, but like the back-support belts worn by people who lift heavy things for a living, it's more likely to leave your muscles weaker in the long run, says Michael Roizen, MD, chief wellness officer at the Cleveland Clinic. "It's not training—it's deconditioning," he says. "And your stomach will go back to its original shape as soon as you take it off."

The Lesson: If you want a tighter, stronger stomach, actual abdominal exercises are your best bet. Try this 4-move routine (no crunches!) to get started.