Zone 2 For Dummies

If you follow any of our work here, you know just how much of a fan we are of cardiovascular exercise. We believe the development of any athlete or human potential requires a balance of strength, flexibility, cardiovascular capacity, and speed.

One of the most common terms in the cardio world right now is ‘Zone 2’. If you’re looking to improve your cardiovascular fitness, then you may have heard of it. This type of training involves working out at an intensity that is moderate but sustainable for an extended period of time. In this blog post, we’ll explore how to do Zone 2 training, how it works, and why it benefits most people, including strength-trained and field-based athletes.

Zone 2 for dummies

What is Zone 2 Training?

Zone 2 training is a type of cardiovascular training that involves working out at an intensity that is approximately 60-70% of your maximum heart rate (MHR). This intensity is moderate and can be sustained for an extended period of time, usually 30-60 minutes. It’s important to note that Zone 2 training is not a high-intensity workout, the purpose of Zone 2, is slow and steady. It is designed to improve your aerobic fitness and endurance. There is a deliberate reason as to why it is slow and steady and crucial to stay close to this range when doing this type of training ( we will go into more detail below).

The image below highlights the different heart rate zones :

Zone 2 for dummies

How to Do Zone 2 Cardiovascular Training

To do Zone 2 cardio, you’ll need to calculate your maximum heart rate. There are a few ways to do this, but one common method is to subtract your age from 220. For example, if you’re 30 years old, your maximum heart rate would be approximately 190 beats per minute (220 – 30 = 190). Your Zone 2 training intensity would then be between 114 and 133 beats per minute (60-70% of 190).

Once you know your Zone 2 training intensity, you can choose an activity that you enjoy, such as running, cycling, or swimming. Start at a comfortable pace and work up to your Zone 2 intensity. You should be able to carry on a conversation while exercising, but you may start to feel fatigued after 30-60 minutes.

The way you go about doing Zone 2 is not as important as doing it and doing it SLOW. Just ensure it is something you enjoy or won’t get sick of, as it is not that exciting.

How Does Zone 2 Cardiovascular Training Work?

When you do zone 2 cardiovascular training, you’re training your body to use oxygen more efficiently. This type of training increases the size and number of mitochondria in your muscles, which are responsible for producing energy. This is the main way in which it improves your fitness. It will improve your body’s ability to use oxygen, meaning, your muscles are more efficient and require less effort from the heart in order to do the same amount of work. Additionally, it also increases the density of your blood vessels, allowing more nutrients to be used through out the body. These physiological changes can lead to improved endurance and performance.

If you want a bit of a nerdier explanation read the two points below:

  • Mitochondrial Biogenesis: Mitochondria are the powerhouses of our cells, responsible for producing energy. Zone 2 cardio has been shown to stimulate mitochondrial biogenesis, increasing the number and efficiency of mitochondria in muscle cells. This adaptation can lead to enhanced energy production during high-intensity strength workouts, delaying fatigue, and improving overall performance. A study published in the European Journal of Applied Physiology in 2019 demonstrated that aerobic exercise increased the expression of genes related to mitochondrial biogenesis in skeletal muscle.
  • Improved Capillary Density: Zone 2 cardio promotes the growth of capillaries within muscle tissues. These tiny blood vessels enhance nutrient and oxygen delivery to muscles, supporting their growth and recovery. A study published in the European Journal of Applied Physiology in 2014 found that aerobic training increased the capillary-to-fiber ratio in skeletal muscles, which positively impacted muscle metabolism and exercise performance.

Why is Zone 2 Beneficial for Strength and Field Athletes?

For strength-trained athletes:

  • Enhanced Recovery and Reduced Fatigue: Research has shown that moderate-intensity aerobic exercise can help clear metabolic byproducts, such as lactate, more efficiently than passive recovery. By promoting better blood flow and oxygen delivery to the muscles, Zone 2 cardio can aid in removing waste products accumulated during intense strength training sessions. This, in turn, leads to reduced muscle soreness and fatigue, allowing strength athletes to recover faster and perform better in subsequent training sessions or competitions. (Reference: Journal of Strength and Conditioning Research, 2016)
  • Increased Mitochondrial Density and Energy Production: Moderate-intensity aerobic exercise has been linked to increased mitochondrial biogenesis, which means an increase in the number and efficiency of mitochondria in muscle cells. Since mitochondria are responsible for producing adenosine triphosphate (ATP), the primary energy currency of cells, improved mitochondrial density through zone 2 cardio translates to enhanced energy production during high-intensity strength exercises. This can lead to better performance in the gym and greater overall strength and power output. (Reference: Medicine and Science in Sports and Exercise, 2018)
  • Enhanced Muscle Capillarization: Zone 2 cardio promotes the growth of capillaries in muscle tissues, which enhances blood flow and nutrient delivery to working muscles. This improved capillarization allows for better oxygen and nutrient supply during strength training, reducing the likelihood of premature fatigue. With enhanced blood flow to the muscles, strength athletes can maintain higher workloads for longer periods, leading to more effective strength and power development. (Reference: American Journal of Physiology – Heart and Circulatory Physiology, 2012)
  • Improved Aerobic Base and Endurance: Even though strength athletes primarily focus on anaerobic activities, developing a solid aerobic base through zone 2 cardio can have a positive impact on their performance. Having a well-developed aerobic system allows strength athletes to recover more quickly between sets and exercises, ensuring they can sustain a high level of effort throughout their training sessions or competitions. It also enables them to perform better in events that require sustained efforts, such as strongman competitions or extended lifting sessions. (Reference: Journal of Applied Physiology, 2013)
  • Body Composition and Weight Management: Moderate-intensity aerobic exercise is an effective tool for managing body composition and weight. Strength athletes aiming to optimize their power-to-weight ratio can benefit from including zone 2 cardio in their training regimen. By promoting fat utilization and caloric expenditure, this form of exercise can help athletes maintain a leaner physique without compromising their muscle mass or strength. (Reference: Obesity Reviews, 2015)
Zone 2 for dummies

For field-based athletes, such as soccer players or basketball players, zone 2 training can improve their endurance and help them maintain a high level of performance throughout a game. Here is how:

  • Improved Aerobic Capacity and Endurance: Field athletes participate in sports that involve continuous movement over extended periods, such as soccer, basketball, rugby, and field hockey. Developing a strong aerobic base through zone 2 cardio can enhance their aerobic capacity and endurance. Research has shown that improved aerobic fitness allows athletes to maintain higher work rates for a more extended period before fatigue sets in, which is crucial for success in field sports. (Reference: Journal of Sports Science & Medicine, 2015)
  • Faster Recovery between Sprints and Bursts of Activity: In field sports, athletes often perform repeated sprints, jumps, and high-intensity movements. Engaging in zone 2 cardio can enhance blood flow and oxygen delivery to muscles, leading to faster clearance of metabolic byproducts like lactate during recovery periods between intense bursts of activity. This enables field athletes to recover more quickly, reduce muscle fatigue, and perform at a higher level during subsequent sprints or plays. (Reference: International Journal of Sports Physiology and Performance, 2011)
  • Increased Muscle Capillarization and Oxygen Delivery: Moderate-intensity aerobic exercise promotes the growth of capillaries in muscles, enhancing blood flow and oxygen delivery. This adaptation is particularly valuable for field athletes as it allows for improved oxygen supply to working muscles during continuous and intermittent high-intensity efforts. Enhanced muscle capillarization can delay the onset of fatigue, ensuring that field athletes can sustain their performance throughout the entire game. (Reference: European Journal of Applied Physiology, 2011)
  • Enhanced Mental Resilience and Decision-Making: Field sports require quick decision-making and mental resilience during intense, fast-paced gameplay. Regular zone 2 cardio can improve cognitive function and reduce mental fatigue, leading to better decision-making on the field. Believe it or not, it is easier to make quick, sharp decisions when you are not fatigued!. (Reference: Sports Medicine, 2019)
Zone 2 for dummies

So there you have it.

Zone 2 in a nutshell. If you’re a strength training athlete or a field-based athlete, and you still don’t think zone 2 will benefit you, you must be crazy! Here at Performance United, we recommend all of our athletes do some form of cardio, regardless of their sport. If you aren’t sure how to implement Zone 2 into your training program or have questions, feel free to reach out.



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