Through the app, you will get instructions on how to properly measure your CO 2 levels. The Lumen device is generally easy to use, though it can be tricky to get an accurate reading. Lower risks of metabolic, cardiovascular, and other diseases.Faster fat loss and lean muscle mass building.Enhanced physical and mental performance.According to the app's founders, a good Lumen flex score is a sign of improved overall health that can burn fat more effectively, which can also result in the following benefits: This metabolic flexibility is measured in the app as Lumen flex score which ranges from 0 to 21. Some practices and habits that can trigger this are exercising, macronutrient manipulation or changing the amounts of carbs, fats, and protein you consume, and time-restricted eating like intermittent fasting. Lumen aims to help you 'hack' your metabolic efficiency so that your body can efficiently shift between burning carbs and fats as fuel, or what's called metabolic flexibility. Lumen can help improve your metabolic dlexibility by enabling you to listen to your body, understand it, and make better, personalized workout and eating decisions based on its analysis.