In the world of fitness, it may seem intuitive that results are directly correlated to how hard you push your body. In other words, you might think that “in order to burn the most fat, and reap the most benefits from exercise, I need to get my heart rate as high as possible and keep it there for as long as possible.” This however can be an oversimplified approach to health both in terms of optimized performance and longevity. It turns out that slow, steady state cardiovascular exercise at around 60-70% of your max heart rate, known as zone 2 exercise, can yield some powerful and long-lasting health benefits. In this article we will explore a few of these notable benefits and how to implement zone 2 exercise into your routine.
Zone 2 Defined
First let’s make sure we are on the same page about what exactly qualifies as zone 2 exercise. The good news is that it is heart rate dependent, meaning that really any type of movement, provided it stays within the above prescribed range, will do the trick. Thus jogging, biking, rowing, walking, and any other form of movement can be utilized as a form of zone 2 so long as you stay within 60-70% of your max heart rate. Another way to ensure you stay in this range is to utilize the talk test. Essentially, what this means is that the intensity of your movement should not limit your ability to speak in full sentences because you are so out of breath, but it should be more difficult to get the words out than if you were sitting down (you should be right on the cusp of not being able to say the sentence without slowing down). You can do this test in junction with a wearable heart rate monitor to establish your zone 2 threshold [1].
Aerobic vs. Anaerobic and Fat Oxidation
In order to understand why this form of slow and steady exercise is effective we have to understand the difference between aerobic and anaerobic metabolism. Aerobic metabolism is the consumption of energy with the presence of oxygen and utilizes energy generated from fat, glucose, and protein while anaerobic metabolism is the consumption of energy without the presence of oxygen and only utilizes glucose as the fuel source [2]. Why is this distinction important to understand? Zone 2 exercise keeps the body in an aerobic state leading to more calories being burned from fat than higher intensity exercise [2]. Additionally, zone 2 is more sustainable for longer periods and consecutive days without over training enabling a sustainable method of burning fat over time. For these reasons, zone 2 is an incredibly effective form of exercise for burning fat.
Zone 2 and Cardiovascular Heath
Not only is zone 2 a great way to burn fat, it also aids in building a strong foundation for cardiovascular health. Think of your cardiovascular endurance as a pyramid. The height of the peak of the pyramid is your VO2 max and the width of the base is your zone 2. You want to have a wide base and a high peak and zone 2 training increases both the base and the height of this pyramid by increasing the size and blood pumping capacity of the heart (though the benefits of zone 2 on VO2 max are less significant than VO2 training itself) [1]. In addition to this, zone 2 has also been linked to an increase in the creation of newer and stronger mitochondria [3]. As the so called “powerhouse of the cell” the mitochondria play a key role in providing energy for the body so the stronger and more abundant they are, the healthier the body is and better it can perform.
How to Implement Zone 2 Into Your Workout Routine
Now that we’ve established that zone 2 is an important factor in physical training, how do we best implement it? It is best to do zone 2 exercise in segments of at least 20 consecutive minutes (or more) at a time. This will compensate for the time it takes for your body to warm up and make the switch over to aerobic metabolism to burn primarily fat. Next, you want to aim for about 120-150 minutes of zone 2 a week. You can find what works best for your schedule keeping in mind the 20-minute minimum. Aside from that its up to you on how you want to implement. I personally prefer 20-30 minutes of zone 2 after lifting during the week with longer sessions (40+ minutes) on the weekends because I’ve noticed that for me, doing zone 2 before lifting degrades my intensity. This may be different for others, so I recommend exploring different methods until you find the right one. After all, the best workout routine is the one you can stick to, and it’s a lot easier to stick to a routine when you enjoy or at least don’t hate it.
Conclusion
Bringing it all together, slow, steady state cardiovascular movement can be more effective for burning fat than other forms of exercise, can increase the amount and efficiency of the mitochondria, and can increase the blood pumping capacity of the heart. Aim for 150 minutes a week with no less than 20 minutes of consecutive zone 2 movement at a time. If you can stick to this for four weeks, you will see noticeable changes in both your body composition, and energy levels. Try the zone 2 challenge and let us know your results!
References
[1] https://www.levels.com/blog/the-metabolic-benefits-of-slow-steady-zone-2-exercise
[2] https://openoregon.pressbooks.pub/nutritionscience/chapter/10b-fuel-sources-exercise/