Zone 2 Cardio
Understanding Zone 2
The term “Zone 2 Cardio” is suddenly becoming a ubiquitous expression in health, wellness, and fitness spaces alike. While the trend might come off as a buzzy catchphrase, it is actually one of the most established and well-researched principles in human physiology. Essentially, Zone 2 is the gear put into motion by your body wherein it uses fat as its primary fuel source (as opposed to carbohydrates) through the act of a low-to-moderate intensity aerobic exercise.
If we consider all of the cardio “Zones” as shifts in gear, they each correspond with a heart rate intensity ranging from Basic to Maximum. Zone 1 (Basic) exerts a heart rate of about 50-60% while Zone 5 (Maximum) exerts 90-100%. Zone 2 is a basic endurance level that corresponds to about 60–70% of your maximum heart rate. In practical terms, it’s a brisk walk, a light jog, or a steady bike ride—sustained for 30 to 45 minutes or more. In this state, your body uses fat as its primary fuel source, your breathing remains steady and controlled, and you are just barely able to hold a conversation.
How Does Reaching Zone 2 Benefit Our Health?
Although Zone 2 has become trendy shoptalk for burning fat, applying it in a holistic way has a plethora of proven benefits for our body systems. Firstly, reaching Zone 2 cardio in a consistent manner helps to build mitochondria (the energy-producing engines inside of every cell.) The stimulation of mitochondrial biogenesis results in energy production (ATP), improved fat metabolization, and a stronger and more resilient heart and vascular system as you age. Essentially, an influx of healthier mitochondria results in more endurance and tenacity in the basic foundation of our bodies.
Along with improving mitochondrial function, Zone 2 strengthens the heart muscle to pump more blood with each beat. Over time, this lowers resting heart rate and improves circulation. It also increases the number of capillaries (small blood vessels) around muscles to improve blood flow and boost red blood cell production to deliver more oxygen to muscles.
The big catch in today’s discourse is that Zone 2 enhances fat oxidation. In this gear, your body relies mostly on fat for fuel. The higher your heart rate soars (to a higher Zone) the more your body uses sources other than fat like carbohydrates (glycogen) and protein for fuel. Higher zones also result in less oxygen intake, which further restricts the body from being able to burn fat. Exercising in Zone 2 gives priority to fat-burning and does not push your body to a point where it needs to rely on those other fuel resources.
How Do Infrared Saunas Get Us to Zone 2?
When you sit in an infrared sauna, your core body temperature rises and your cardiovascular system responds. Your heart rate climbs to that 60-70% zone, blood vessels dilate, and circulation increases. Your body works to cool itself in the same way it does during moderate aerobic exercise. The physiological stress is real, and so are the adaptations.
An infrared sauna can replace an aerobic workout when needed - without joint load, without equipment, and without effort. Using an infrared sauna on “off days” or on a regulated schedule can help to augment results for wellness and fitness goals while also being a relaxing experience.
In addition to putting your body into Zone 2 cardio, infrared saunas are one of the most effective detoxification tools available to us - helping your body sweat out chemicals, heavy metals, and environmental toxins over time. Infrared reduces inflammation, supports recovery, and leaves most people feeling clearer and calmer after a session.
Infrared saunas cannot replace movement. But for the days you can’t get a long walk or ride in - or when your body needs recovery more than exertions, it’s one of the most effective tools you can reach for.
