How the Lumen CO2 Breath Test Reveals What Fuel Your Body Is Burning

Get the lowdown on how Lumen’s co2 breath test shows exactly what fuel your body’s burning.

If you train regularly, or even just try to stay active during a busy week, you’ll know exactly what it feels like to wake up full of energy one day and then feel completely flat the next. Even when you’re eating well and staying consistent, your body still seems to switch things up without warning and it can be hard to get to grips with what’s going on.

Well Lumen helps you make sense of it all. It uses a quick co2 breath test to show you what fuel your body’s running on and how that might impact things like your energy levels.

The device itself is tiny and incredibly straightforward. You breathe into it, the app analyses the carbon dioxide in your breath, and you get a reading that shows whether you’re burning more carbs or more fat. The whole process is quick, clear, and easy to understand. It’s the kind of check you can do before you’ve even had your morning coffee.

And if you do decide to try it, remember to use our Lumen discount code GYMDISCOUNT for 10% off at the online checkout.

How the Lumen CO2 Breath Test Works

When you breathe into Lumen you’re doing more than taking a quick reading. You’re triggering a proper co2 breath test that shows what fuel your body is using in that moment.

Inside the device you’ve got sensors that pick up the carbon dioxide in your breath along with airflow and pressure measurements. All of that helps the app understand whether you’re burning mostly carbs or mostly fat.

The process is really simple. You take a slow inhale, hold it for a couple of seconds, then breathe out steadily into the device. Lumen measures the carbon dioxide in that breath and sends the result straight to your app.

A higher carbon dioxide level usually means your body is relying more on carbs, while a lower level points towards fat burning.

The app then takes that info from your co2 breath test and uses it to give you real insights into what your body is doing. But that’s not all. It also then gives you insights and strategies you can put into action to help you reach your goals.

How The CO2 Breath Test Helps You Make Better Choices

Once you start using Lumen’s co2 breath test consistently, you’ll begin to spot patterns you never noticed before. A heavy meal late at night shows up the next morning. A good sleep routine keeps your readings steadier. A tougher training day or a long walk might shift things around too.

Even small lifestyle choices, like drinking more water or eating earlier in the evening, can create changes you see in your morning score.

And the best part is how easy it becomes to use this feedback.

Maybe your reading suggests you’d benefit from a more structured breakfast. Maybe it nudges you towards lighter carbs because your body’s already doing a great job using fat.

You don’t need complicated meal plans or intense tracking. You just follow the guidance that lines up with the co2 breath test result you got that morning.

What You Get With Lumen

So what do you actually get when you sign up with Lumen? Well, for the current price of £299 you get the Lumen device itself, and that includes unlimited lifetime measurements, which means you can test as often as you want without worrying about any limits or extra costs.

You also get 12 months of premium membership that unlocks your personalised nutrition plans, meal timing guidance, macronutrient coaching, and daily recommendations that adapt to your readings.

The membership also gives you access to more than 30 integrations, including Apple Health, Google Fit, Garmin, Oura, Whoop, Strava, MyFitnessPal, and others. Everything works together so you have a full picture of your daily habits.

On top of that, you get unlimited support from a metabolic expert, which is a nice little safety net if you ever want extra help or clarification.

Final Thoughts

If you’re trying to understand your body better and want a simple way to see whether you’re burning carbs or fat, Lumen’s co2 breath test gives you the kind of clarity that’s normally hard to get.

It helps you link your habits to your energy, makes your daily choices feel more intentional, and turns your metabolism into something you can actually work with.

So if you’re ready to give it a try for yourself head to the Lumen website to get started, and don’t forget to use our Lumen discount code GYMDISCOUNT for 10% off your order.