They're at the gym, on hiking trails, in public parks and on social media feeds, where influencers claim wearing one can do incredible things for your health. "The benefits to walking with a weighted vest are insane," one paid promoter, theashleywill, said in a recent post on TikTok. "Your posture, your bones, increased calorie burn, your strength, your endurance," she continued. "I could go on and on and on."