Zone 2 Training: The Science-Backed Way to Get Fit

You might have heard the buzz about zone 2 training, but do you know what it really means for your body and why it’s so beneficial for your fitness goals? Zone 2 training is more than just a fancy term – it’s a science-backed way to improve your endurance and burn fat. 

Keep reading to learn how zone 2 training can boost your health and how you can get started today.

Getting to know your zones

Have you ever wondered why your heart beats faster when you exercise? Or why some workouts make your heart race more than others? Your heart rate is a powerful indicator of how hard your body is working and how fit you are. Knowing how your heart rate changes with exercise can help you train smarter and achieve your fitness goals quicker. 

When you work out, your heart rate changes depending on how hard you push yourself. This is good because it means your body is adapting to the challenge and getting stronger. But how do you know if you’re working out at the right intensity for your goals? That’s where heart rate zones come in. These zones show you how much your heart and lungs are pumping to keep up with your activity, whether enjoying a leisurely walk, lifting weights, or running on a treadmill. 

Heart rate zones typically range from zone 1, which is very light and easy, to zone 5, which is very intense and challenging. Each zone has different benefits and drawbacks for your fitness and health.

Let’s take a closer look at each zone and understand how they relate to heart rate:

Zone 1 (50-60% of max heart rate): At this lowest level of effort, you can breathe easily and talk comfortably. This zone is suitable for warming up, cooling down, and recovering from more strenuous workouts. 

Zone 2 (60-70% of max heart rate): This is a level of effort where you can still talk but not sing. This zone is optimal for improving your athletic endurance and burning fat. 

Zone 3 (70-80% of max heart rate): This is a high level of effort where you can only say a few words at once. 

Zone 4 (80-90% of max heart rate): This is a very high level of effort where you can barely speak a word. 

Zone 5 (90-100% of max heart rate): This is the maximum level of effort where you can’t speak. 

Zone 2 training: the sweet spot for fat-burning and cardio fitness 

While it’s true that you’ll always use some fat for energy when you exercise, exercise on the lower end of the intensity spectrum burns a higher percentage of fat than more vigorous exercise. That’s because as the heart rate increases with more effort, the body doesn’t take in as much oxygen, causing it to shift to using a different energy source that is more plentiful – carbohydrates. Relying on less fat and more carbs for fuel results in one thing: a decreased rate of fat burn. So, sticking with lower-intensity exercises like zone 2 is a surefire way to boost weight loss because it’s when your body uses up the most fat for its energy. 

Zone 2 workouts may be optimal for burning fat, but they also offer other health benefits that may not be as readily found even in more intense workouts.  HIIT, or high-intensity interval training, is the craze sweeping the nation as a form of exercise involving alternating between bursts of intense activity and periods of rest. HIIT has many believing it is the ultimate way to boost fitness, but is it really the best option?

Scientists are discovering that a lower-intensity regimen called polarized training may be the key to a healthier, fitter body. A polarized training session typically includes 80% low-intensity and 20% high-intensity activity. Although there is no one standard, and these ratios can differ from workout to workout, the goal remains to focus on lower-intensity movement.

There are several reasons polarized training works. For starters, polarized training can help prevent burnout and injury by providing a more balanced approach to exercise. And studies have also shown that low-intensity training can significantly improve athletic factors, even compared to other exercise programs.

For example, one randomized controlled trial compared the effects of polarized training, threshold training, high-intensity interval training (HIIT), and high-volume training on endurance performance in 48 healthy, well-trained athletes over nine weeks. The researchers found that among the four exercise methods, polarized training resulted in the greatest improvements in key endurance variables, such as VO2max and time to exhaustion. VO2max is the maximum amount of oxygen your body can use during intense exercise. It measures your aerobic fitness and is often used to predict athletic performance. The polarized training group showed an 11.7% increase in VO2max, followed by the HIIT group with only a 4.8% increase. The change in VO2max in the polarized training group was also greater than the threshold training and high-volume training groups. In addition, the polarized training group showed a 17.4% increase in time to exhaustion, followed by the HIIT group, with an 8.8% increase. The time to exhaustion improvement in the polarized training group was also higher than in the threshold and high-volume training groups. Time to exhaustion is the amount of time you can maintain a certain intensity of exercise before you cannot continue. So, having a higher time to exhaustion means you’ll be able to perform endurance activities for longer.

A second recent study confirmed the health benefits of polarized training, looking at its effect on body composition and cardiorespiratory function of 16 male and female cross-country skiers. The researchers found that after 12 weeks of polarized training, both male and female athletes saw a decrease in body fat, from 18.1% to 12.7% and 29.1% to 21.4%, respectively. VO2max increased by 7.72% in male athletes and 6.32% in female athletes, and treadmill exercise time increased by 5.39% for male athletes and 2.23% for female athletes. Moreover, the 50% recovery time from the maximum heart rate to the target heart rate decreased by 64.52% in males and 6.48% in females. A faster recovery time is beneficial because it allows you to get back to your training sooner, leading to enhanced fitness and performance. 

How to start zone 2 training 

If you’re new to zone 2 training, the first step is to determine your target heart rate. Knowing your target heart rate will help you get the most out of your workouts by staying in the range where you’re burning more fat for fuel. 

The following chart from the American Heart Association can help you determine the heart rate to aim for based on your age. These numbers reflect zone 2 intensity or 60 to 70% of your maximum heart rate.

So, for example, a 45-year-old should aim for a heart rate of 105 to 123 beats per minute for 80% of their workout to reap the rewards of zone 2 training.

Once you’ve determined your zone 2 target heart rate, it’s time to find a method to measure it while you train. There are easy ways to measure your heart rate, including wearing a chest strap, a smartwatch, or using a fitness app. If going the tech-free route, try the trusty “talk test.” To do this, start exercising. After a few minutes, if you can talk in complete sentences without getting out of breath, consider yourself in zone 2.

There are many different types of zone 2 exercises that you can do. Some great ideas include low-impact activities like walking, jogging, cycling, swimming, rowing, and using an elliptical trainer. But the best exercises are the ones that you enjoy and that you can do consistently. 

Here’s how Biosense can help

Biosense is a valuable tool for anyone looking to improve their health and fitness while in zone 2 training. Biosense measures the number of ketones in your breath, letting you know instantly whether your workout efforts, along with the way you’re eating, are promoting or hindering your fat burn goals. Biosense can also help you track your progress over time while providing guidance on how to adjust your exercise routine as needed. Simply put, Biosense ensures you stay on the shortest path toward reaching your health goals. 

The bottom line 

If you’re looking for a sustainable way to lose weight and improve your overall health and fitness, zone 2 training is a great option. Zone 2 training is a low-impact form of exercise that people of all ages and fitness levels can do. There are many benefits to zone 2 training, including increased fat burning, improved cardiovascular fitness, greater endurance, and reduced risk of injury. Paired with Biosense, you’ll get the most out of your workout by knowing when you’re right on track – and when it’s time to make an adjustment. Before starting any new exercise routine, including zone 2 training, it is always a good idea to check with your doctor, as they can help create a safe and effective plan for you.