The Body Electric

W‘s beauty director gets physical with this gadget.

Athos Core

With my three Nike+ FuelBands and my Jawbone Up, I thought I had exercise monitoring covered, but the Athos Core—a pillbox-size gadget that slips into the pocket of the brand’s exercise tops or shorts and measures muscle movement, heart rate, and breathing—might be a game changer. After your workout, Athos can call you out on any overcompensation or overexertion—without the patronizing tone and public humiliation that have forever put me off Spin class.