Most athletic wearables focus on heart rate, which can be helpful but conveys nothing about how your muscles are performing or how to adapt your workout. “You have more information about your phone, your computer, and your car than you do about your body, which is a billion times more important,” says Alessandro Babini, the cofounder and CEO of Humon, which makes the Hex, a wearable muscle-oxygen sensor that’s helping elite athletes achieve performance breakthroughs and work out more safely and effectively. The $295 device has consistently sold out since it launched in February 2018, sales increased 30% month over month in 2018, and NFL and NBA teams have used it to gauge how warmed up athletes are before practices and games. Here’s how it works:
1. Red vs. Blue Blood
When oxygen enters blood through the lungs, it binds with hemoglobin in the cells and turns bright red. After oxygen is ferried to and used by muscles, the blood turns dark blue-red. The Hex interprets how well muscles are working based on blood color.
2. The Hex
The Hex shines red and infrared light into the muscle, then four evenly spaced sensors read how much of each light passes through the muscle and how much is absorbed.
3. Light Absorption
Bright-red oxygenated blood will absorb more infrared light and allow red light to pass through, while blue-red, oxygen-poor blood will absorb more red light and allow infrared to pass through.
4. Tracking Progress
The Hex measures oxygen levels in an athlete’s thigh muscle over the course of a workout and, using proprietary software, generates colored graphs that show whether the user’s muscles are consuming oxygen at a rate that’s sustainable (green), unsustainable (red), borderline (orange), or low (blue).