It was nearly two years ago that we first covered Lumen, a gadget and app combo that claims to track your metabolic flexibility — how good your body is at switching between energy sources. It does so ...

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In the most recent episode of 'What the Wellness,' star Ella Dove gives the Lumen metabolism tracker a try with the power of her own breath. Our editors independently select these products. Making a ...

Your body’s fuel-burning system has been a black box until now. The Lumen Metabolism Tracker cracks it open with a simple breath test, revealing whether you’re burning carbs or fat at any given moment ...