Boost Your Longevity with Easy Zone 2 Training

Have you ever thought about how you can live longer and healthier? Zone 2 training could be the key to increasing your healthspan, or the number of years you live with vitality and optimal performance. This type of moderate-intensity training strengthens mitochondria and improves your body's ability to use energy efficiently. It helps prevent disease and lays the foundation for an active life.

What is heart rate zone 2?

In purely mathematical terms, heart rate zone 2 is approximately 60 to 70 percent of your maximum heart rate, which varies based on your age. One rule of thumb is to subtract your age from 220. For a 50-year-old, for example, this would correspond to about 102–119 beats per minute. Wearables, such as the Apple Watch or the Polar H10 chest strap, can help you monitor your heart rate. They often offer predefined zones to help you stay in the aerobic zone and avoid the anaerobic threshold. Heart rate zone 2 is a specific aerobic training zone in which your body primarily uses fat as an energy source, and lactate production, a byproduct of more intense exercise, remains balanced.

The 5 heart rate zones at a glance

The following heart rate zone percentages are only guidelines because they are based on estimated maximum heart rates, which vary from person to person due to factors such as genetics, fitness level, and age. Additionally, calculations of maximum heart rate (e.g., 220 minus age) are rough estimates that may not reflect one's actual physiological limits. Therefore, these percentages are general guidelines. However, personal markers such as perceived exertion, lactate thresholds, or direct VO₂ max tests provide more accurate insights for training.

• Zone 1 (recovery and low intensity): 50–60% of maximum heart rate; ideal for active recovery and regeneration.

• Zone 2 (aerobic endurance): 60–70% of maximum heart rate; crucial for mitochondrial health, fat burning, and metabolic flexibility. Recommended time: 3–5 hours per week, but at least 2 hours spread over several sessions.

• Zone 3 (aerobic threshold): 70–80% of maximum heart rate; improves endurance and cardiovascular system, but not a priority for healthspan.

• Zone 4 (Anaerobic Threshold): 80–90% of maximum heart rate; strengthens VO2max and improves performance. Recommended time: 1–2 sessions per week, at least 20 minutes, in intense intervals.
• Zone 5 (maximum intensity): 90–100% of maximum heart rate; promotes explosiveness and maximum performance. Recommended time: sparingly, occasionally 10–15 minutes as part of interval training.

Why is zone 2 training important?

Zone 2 training improves the function of your mitochondria, the “powerhouses” of your cells. It helps to use fat as an energy source and combat insulin resistance.

The benefits of regular training in Zone 2 are impressive:

• Mitochondrial health: Zone 2 training strengthens your mitochondria—the powerhouses of your cells—and increases their ability to produce energy efficiently. Well-functioning mitochondria promote cellular energy efficiency and slow down the aging process through Zone 2 training.

• Fat utilization: During Zone 2 training, your body uses fat as its main source of energy and reduces its dependence on carbohydrate stores (glycogen). Improved fat utilization through Zone 2 training increases your endurance and supports a healthy body fat percentage.

• Metabolic flexibility: Zone 2 training teaches your body to switch flexibly between fat and carbohydrates as energy sources. This flexibility reduces the risk of metabolic diseases and ensures a stable and sustainable energy supply.

• Cardiovascular health: Zone 2 training strengthens your heart and improves the efficiency of your oxygen supply system. It reduces the risk of heart disease and increases your overall fitness through regular exercise in Zone 2.

• Cognitive health: Zone 2 training improves blood flow and oxygen supply to your brain, which increases your mental performance. It supports memory and concentration and reduces the risk of dementia in the long term.

• Glucose homeostasis: Regular training in Zone 2 improves insulin sensitivity, keeping your blood sugar levels stable. It protects against type 2 diabetes and helps you effectively regulate your energy balance through Zone 2 training.

Regular Zone 2 training therefore provides a comprehensive foundation for staying active and healthy for longer – an essential investment in your personal performance and healthspan.

Integrating Zone 2 training is easy

Zone 2 training is really easy to do and suitable for almost any fitness level. Here is a guide to get you started:

• Duration and frequency: Start with two to three 30-minute sessions per week. As you progress, you can increase to four to five 45-minute sessions. The goal is to train in Zone 2 for a total of three to five hours per week.

• Activities: Suitable activities include cycling, brisk walking, swimming, or running. For beginners, brisk walking on slightly sloping terrain can also be ideal. Use equipment such as exercise bikes or treadmills to keep the intensity constant.

• Intensity control: Use the “conversation test” to make sure you are in Zone 2. You should still be able to talk, but it should feel slightly strenuous. You can also monitor your heart rate—it should be between 70 and 85% of your maximum heart rate. You can use the appropriate apps to display this range during your workout.

Why muscle length matters

Interestingly, the legs play a particularly important role in Zone 2 training. They contain significantly more slow-twitch muscle fibers than the arms. These fibers are equipped with more mitochondria and are therefore better able to efficiently use fat as an energy source. This means that exercises that primarily work the leg muscles—such as cycling, walking, or running—are more effective at promoting mitochondrial health. The arm muscles, on the other hand, rely more on fast-twitch fibers, which have a lower mitochondrial capacity. As a result, they produce lactate more quickly and reach the training limits of Zone 2 sooner. To achieve the best results for your healthspan, you should therefore choose exercises that focus on your legs.

 

The science behind Zone 2 training

Scientific studies such as those by Iñigo San Millán and George Brooks prove that Zone 2 training is the foundation of metabolic health. Studies have shown that people with metabolic diseases are hardly able to utilize fat efficiently. Regular training in Zone 2 significantly improved their ability to burn fat and promoted their metabolic flexibility.

It is also interesting to note that even professional athletes spend up to 80% of their training time in Zone 2 to optimize their basic performance. This is also beneficial for recreational athletes, as the effects achieved—from improved glucose uptake to strengthening the mitochondria—play a crucial role in healthspan.

Imagine looking back at the end of next year and feeling the changes: more energy in everyday life, a more stable metabolism, and the feeling that you have done something really good for your body. And it all started with a simple decision: 150 minutes per week for your health and your future. Why not make 2025 the year you integrate Zone 2 training into your everyday life? At first, it may just be small steps—a walk after work, a leisurely bike ride on the weekend. But this routine will become an investment in yourself. Zone 2 training is not a short-term trend, but a sustainable strategy for better health and longevity. Get started, find your rhythm, and make 2025 your year of change. You'll be surprised how much better you can feel—week by week, step by step.

 

Want to learn more?

• Outlive: The Science & Art of Longevity  by Peter Attia (Chapter 12)

• Dr. Andy Galpin: Optimize Your Training Program for Fitness & Longevity | Huberman Lab Guest Series - YouTube

• A guide to Zone 2 training: its profound impact on health, detailed training instructions, addressing male and female differences, and more - Peter Attia

• The [almost] unbelievable effects of a high maximal aerobic capacity on all-cause mortality - Peter Attia

• Describing Training Zones- Dr. Inigo San Millan

• Zone 2 Training: The Science Behind Peak Metabolic Health | Dr Inigo San Millan | The Proof Podcast