The Benefits of Zone 2 Cardio
Written by Fritz Nugent

Have you ever gone out for a run or rode a bike next to a friend and chatted the entire time? Chances are you were in “Zone 2”, which is an old term that has recently gained popularity for several reasons. Before we get into the weeds with zone 2 training, let me first place it in context with the rest of its friends, zone 1, 3, 4, and 5.

What Is Zone 2 Cardio?

Training zones are based on heart rate percentages and correspond to different levels of exercise intensity. Zone 1 (50-60% of one’s maximum heart rate) is light activity, great for warm-ups and recovery. Zone 2 (60-70%) improves aerobic endurance and fat oxidation. Zone 3 (70-80%) is moderate intensity, boosting cardiovascular fitness. Zone 4 (80-90%) targets anaerobic endurance, increasing power and speed. Zone 5 (90-100%) is maximal effort, focusing on peak performance and strength, typically used for short bursts or high-intensity intervals. Each zone plays a role in developing different aspects of fitness, from endurance to power.

“Zone 2 Cardio”, or “Zone 2 Training” is a heart rate training zone characterized by moderate-intensity effort, where your body primarily relies on aerobic metabolism (fat as a fuel source). It is often referred to as the “easy” or “conversational pace” zone because you should be able to maintain a conversation without gasping for air while you plod along. There are a host of benefits available from zone 2 training, and gained popularity recently due to its proven benefits for health, longevity, and performance. It improves mitochondrial function, metabolic health, and cardiovascular efficiency, aligning with the growing focus on sustainable fitness and recovery. In addition, advances in wearable technology have made monitoring heart rates for Zone 2 more accessible, while endorsements from fitness influencers and exercise science researchers have amplified its visibility. Athletes across various disciplines, including endurance and CrossFit, are adopting Zone 2 to build aerobic capacity, enhance recovery, and balance high-intensity training, making it a cornerstone of modern fitness programming.

How to Calculate Zone 2 Training

The simple formula for calculating your heart rate zone for “Zone 2 training” is:

Max HR×(0.6 to 0.7)

Or in simple terms, training with your heart rate at 60 to 70% of your maximum. My max heart rate is about 195 BPM, which puts my zone 2 parameters at 117-136 BPM. If you don’t know your max heart rate, you can estimate it using 220 minus your age. If you have a chest strap or fitness watch/tracker, this may also provide your estimated maximum heart rate.

There are more complex ways to quantify this training zone, but for the scope of this introductory article, I’ll stop here and move to benefits next.

Benefits of Zone 2 Cardio

Zone 2 training offers a range of benefits, including improvements in cardiovascular and mitochondrial health, fat oxidation, and the development of a solid aerobic base. It also helps reduce stress, supports longevity, and boosts mood through endorphin release.

Cardiovascular Benefits

This training strengthens the heart, enhances blood-pumping efficiency, and increases stroke volume, allowing the heart to pump more blood per beat while reducing excessive heartbeats during exercise and rest. Additionally, Zone 2 training enhances fat oxidation for better metabolic flexibility and supports mitochondrial growth, improving energy production and overall metabolic health.

Performance benefits

Building a strong aerobic base through Zone 2 training improves endurance and the ability to sustain higher-intensity efforts over time. It also accelerates recovery by improving blood circulation and oxygen delivery to muscles, helping clear metabolic waste and reduce fatigue. This makes it essential for athletes seeking to optimize both performance and recovery.

Hormonal benefits

Zone 2 also supports hormonal balance by reducing cortisol levels, managing stress, and promoting recovery. It enhances insulin sensitivity, improving the body’s ability to regulate blood sugar, which contributes to overall metabolic health and resilience.

Health and longevity benefits

Moreover, Zone 2 training helps regulate blood pressure and improve cardiovascular function, playing a key role in preventing chronic diseases like heart disease, type 2 diabetes, and obesity, making it foundational for long-term wellness.

Psychological benefits

For mental health, Zone 2 training enhances mood, boosts mental clarity, and can provide a mindful experience through focused breathing, supporting overall well-being. Like anything else in this world, you get out what you put in. If you go into a training session with the intention to garner this type of response, the chances of achieving your targets increase!

CrossFit-specific benefits

In CrossFit, incorporating Zone 2 cardio builds an aerobic base to sustain high-intensity efforts during WODs, prevents overtraining through active recovery, and supports members’ health goals, particularly weight loss and general well-being. Want to improve your Fran time? Get stronger and build your aerobic base, which zone 2 training can help with.

How Can I Incorporate Zone 2 Cardio In My Weekly Routine?

To incorporate Zone 2 training into your weekly routine, aim for 2–4 sessions per week, each lasting 30–60 minutes, depending on your goals. You can schedule these sessions on non-WOD days, after lighter workouts, or even post-WOD as a cool-down. Zone 2 can also be used as active recovery on rest days. Focus on steady-paced activities like running, cycling, and rowing. Machines like the Row and Ski Erg or Assault Bike also work well, all of which are ideal for maintaining the required heart rate.

Summary

Zone 2 training is a versatile and powerful tool for improving overall fitness and health. By enhancing cardiovascular and mitochondrial health, increasing fat oxidation, and building a strong aerobic base, it supports endurance, performance, and recovery. Zone 2 training also contributes to hormonal balance, stress reduction, and improved metabolic health by boosting insulin sensitivity and regulating blood pressure. It plays a key role in preventing chronic diseases and promoting longevity. Additionally, it benefits mental health by improving mood and clarity. In CrossFit, Zone 2 cardio enhances performance, prevents overtraining, and supports members’ health goals, particularly weight loss and general well-being.