Zone 2 cardio has become a buzzword, touted by fitness influencers, tech enthusiasts, and endurance athletes alike. But what exactly is it, and why is it gaining so much attention? This article delves into the details of Zone 2 training, exploring its benefits, how to incorporate it into your routine, and why it might be the key to unlocking your weight loss and endurance goals.
Understanding Zone 2 Cardio
Zone 2 cardio refers to a steady-state aerobic workout performed at an easy to moderate level of intensity. Melissa Kendter, CPT, explains that this training method typically elevates your heart rate to between 60 and 70 percent of your maximum heart rate (HR max). The goal is to maintain a pace that is fast but sustainable, where you feel like you're breathing a bit harder than usual but can still carry on a conversation.
Determining Your Zone 2 Heart Rate
To train effectively in Zone 2, it's crucial to know your target heart rate range. Traditionally, HR max is estimated by subtracting your age from 220. However, Dr. Martha Gulati suggests this formula may not be the most accurate for women. Based on her research, she proposes a different calculation:
For women: HR max = 206 - (0.88 x your age)
Once you've estimated your HR max, you can calculate your Zone 2 range:
Read also: The Noom Weight Loss Zone explained
- Lower threshold: 0.6 x (206 - age x 0.88)
- Upper threshold: 0.7 x (206 - age x 0.88)
For example, if you're 25 years old, your Zone 2 training heart rate should be roughly 110 to 128 beats per minute. You can monitor your heart rate using a heart-rate monitor, chest strap, or similar tracking device.
The Talk Test
If you don't have access to a heart rate monitor, the "talk test" is an effective alternative. Kendter says, "You should be able to hold a conversation during Zone 2 training. You shouldn't be gasping for air." Another method is to focus on your breathing: "You should be able to inhale for three to four counts and exhale for three to four counts, and that means that you're in the proper zone."
The Benefits of Zone 2 Cardio
Zone 2 cardio offers a multitude of benefits for your health and performance.
Improved Heart Health
The CDC classifies Zone 2 cardio as an aerobic workout, meaning it strengthens your heart. During Zone 2 training, your body uses oxygen to create the energy needed to fuel your muscles. Moderate-intensity aerobic activity can lower your risk of heart disease and even heart attacks. It can also help lower blood pressure, raise good cholesterol, and manage blood sugar.
Enhanced Performance and Power
While Zone 2 is a lower intensity than other zones, it can improve your performance at higher intensities. Aerobic exercise increases the number and size of mitochondria and causes your muscle capillaries to grow. This improves your body's ability to deliver and use oxygen, boosting your performance in other aspects of your fitness routine. Kendter adds, "It then helps to improve your power output at higher intensities, your efficiency, and your overall strength."
Read also: Learn About the Zone Diet
Increased Endurance
Consistent Zone 2 cardio can help build your aerobic base, which determines how long you can sustain aerobic activity. Through repeated Zone 2 sessions, you'll increase your cardiovascular fitness, improve your body's capacity to generate energy from oxygen, and boost your ability to perform steady-state work for a long period.
Reduced Risk of Burnout and Overtraining
Zone 2 cardio is challenging enough to drive meaningful adaptations but not so taxing that it's difficult to recover from. This reduces the likelihood of fatigue and overtraining. "Becoming a more agile, well-rounded person is really about building your [aerobic] base in that Zone 2 training," notes Kendter. "Because if you do hard efforts all the time, you'll overdo it. That's when it can lead to overtraining, injuries, or eventually a drop in motivation just because your body burns out."
Improved Mitochondrial Function
Zone 2 exercises have the ability to improve the health of your mitochondria, which play a key role in your overall health.
Boosted Aerobic Capacity
Zone 2 training can increase your body’s VO2 max, reflecting your aerobic fitness. A higher VO2 max is associated with longevity, better brain function, cardiovascular health, and a lower risk of heart disease, hypertension, and stroke.
Aids in Recovery
Zone 2 training works your muscles and heart without leading to lactate accumulation, allowing for more effective recovery.
Read also: Longevity-Boosting Breakfast Recipes
Zone 2 Training and Weight Loss
Zone 2 cardio is often called the "fat-burning" zone because your body utilizes fat as an energy source. Kendter clarifies, "It's your body's way of utilizing fat as an energy source so that you're able to run longer, walk longer, swim longer, or cycle longer. It's not actually burning fat off your body. That's a big misconception."
Zone 2 Cardio for Body Composition
Zone 2 cardio can contribute to weight loss because it allows you to move your body more consistently. You're also more likely to stick with enjoyable and sustainable physical activity, leading to more progress in the long run.
Calories and Intensity
While Zone 2 training doesn't target body fat specifically, and higher-intensity activities generally burn more calories per minute, Zone 2 has unique perks for weight loss. It builds endurance, allowing you to sustain a workout for longer, which can increase the total calories burned. It may also be an easier entry point than higher-intensity workouts.
Fat Burning and Energy Systems
In Zone 2, your body primarily uses fat as its fuel source, enabling increased fat burning compared with higher intensity exercises that rely more on carbohydrates and protein for fuel. This encourages the mitochondria in your body to produce the most ATP, improving your fat-burning abilities.
The Importance of Sustainability
Experts agree that all forms of exercise can be effective for losing body fat, and it really comes down to your preferences and whether a particular exercise regimen is sustainable.
How to Incorporate Zone 2 Training into Your Routine
Zone 2 cardio can be incorporated into various activities, making it accessible to everyone.
Types of Zone 2 Activities
- Running: An easy jog at a conversational pace.
- Walking/Hiking: A brisk walk on a flat surface or with a gentle incline.
- Cycling: A relaxed bike ride, either outdoors or on a stationary bike.
- Swimming: Swimming laps at a steady pace.
- Elliptical Training/Rowing: Using gym equipment to maintain a steady, low-intensity effort.
- Rollerblading: Maintaining a consistent, moderate pace.
- Walking Your Dog: As long as you can maintain a slightly elevated heart rate.
Duration and Frequency
Generally, a Zone 2 cardio workout should be at least 20 to 30 minutes, gradually progressing to 60-minute sessions as your fitness improves. Aim to incorporate Zone 2 training into your routine twice a week to score the cardiovascular and performance benefits. For optimal results, complete around 3-4 hours of Zone 2 training every week.
Zone 2 cardio is low-intensity, so you’re able to do it every day without any serious repercussions. “If you're training for a marathon, an Ironman, or just improving your fitness, you can definitely go for a brisk 20- or 30-minute walk every single day-and that's Zone 2 training,” says Kendter.
Tips for Staying in Zone 2
- Monitor your heart rate using a heart rate monitor or fitness tracker.
- Use the talk test to gauge your intensity.
- Maintain a consistent pace and avoid sudden increases in workload.
- Stay hydrated.
- Adjust your activity based on environmental factors like temperature.
If you notice your heart rate jumping out of the zone, slow down or take a break. "If you need to stop and walk or take a break from whatever you're doing, take a break and then come back in a minute," says Kendter. "Or just slow it down until your heart rate lessens or you're able to talk or breathe normally again."
Potential Pitfalls and Considerations
While Zone 2 training offers numerous benefits, it's essential to be aware of potential pitfalls.
Difficulty Maintaining Heart Rate
Some people struggle to keep their heart rates low enough to sustain Zone 2 levels throughout their entire exercise session.
The Boredom Factor
Many athletes find low-intensity work boring, and it can be a blow to the ego to spend your entire Saturday jog getting passed. It also takes patience.
Over-Reliance on Technology
The gadget-focused athlete can sometimes find themselves contorting their behaviors to satisfy their trackers. Forum posts from Garmin, Polar, Apple Watch show users having difficulty finding and staying in Zone 2. Extended low-intensity exercise is not always highly regarded by the machines. Garmin users, for example, have found their low-and-slow training marked as “unproductive.”
Accuracy of Fitness Trackers
San Millán said that some technology may be able to capture data and assemble sophisticated graphs, but that does not mean they’re representing reality. Dr. Levine went even further. “You should throw everything out the window if you've not had a maximal exercise test to measure your heart rate and ventilation for yourself,” he said. These tests typically involve getting on a treadmill or bike while breathing into a tube, while your oxygen uptake, carbon dioxide output, heart rate, and other stats are monitored. Dr. San Millán is similarly doubtful about fitness trackers and their Zone 2 calculations. “After 30 years, and doing research, I still would not be able to tell you where your Zone 2 is without testing you.”
Zone 2 as Part of a Balanced Fitness Plan
Zone 2 training should be around 80 percent of that pie, with the remaining 20 percent done at high intensity.
For higher-intensity work, Levine likes the old Norwegian ski team workout: a 4x4 aerobic interval workout consisting of 4 minutes at 95 percent of max heart rate, followed by three minutes of rest, repeated four times. “That's the best workout to build aerobic power in a short period of time.”