Zone 2 training for more healthspan and longevity

Have you ever thought about how you can not only live longer, but also healthier? Zone 2 training could be the key to increasing your healthspan – the years you are vital and productive. This type of moderate-intensity training strengthens mitochondrial health and improves your ability to use energy efficiently. It not only helps prevent disease, but also lays the foundation for an active life.

What is heart rate zone 2?

In terms of numbers, heart rate zone 2 is around 70-85% of your maximum heart rate, which varies depending on your age. A rule of thumb for this is 220 minus your age. For a 40-year-old person, this corresponds to about 126-153 beats per minute. Wearables such as the Apple Watch or Garmin devices help monitor heart rate and often offer predefined zones to help you stay in the aerobic zone and avoid the anaerobic threshold. Heart rate zone 2 describes a specific aerobic training zone in which your body mainly uses fat as an energy source and the production of lactate – a by-product of more intense exercise – is still balanced.

The 5 heart rate zones explained

The following heart rate range percentages are intended as a general guide, as they are based on an estimated maximum heart rate, which can vary from person to person due to factors such as genetics, fitness level, and age. Additionally, maximum heart rate calculations (e.g., 220 minus age) are rough estimates and may not accurately reflect your true physiological limits. These percentages serve as general guidelines, but personal markers such as perceived exertion, lactate thresholds, or direct VO₂ max testing provide more precise 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 the 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, but 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 heart rate zone 2 training important?

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

The benefits of regular zone 2 training are impressive:

• Mitochondrial health: Zone 2 training strengthens your mitochondria – the power plants 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 flexibly switch between fat and carbohydrates as an energy source. 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 lowers the risk of heart disease and increases your overall fitness when done regularly.
  
• Cognitive health: Zone 2 training improves blood flow and oxygen supply to your brain, boosting your mental performance. It supports memory and concentration and lowers the risk of dementia in the long term.
• Glucose homeostasis: Regular Zone 2 training improves insulin sensitivity, which helps your blood sugar levels to remain stable. It protects against type 2 diabetes and helps you to effectively regulate your energy levels through zone 2 training.

Regular zone 2 training thus provides a comprehensive foundation for staying active and healthy for longer – an indispensable investment in personal performance and healthspan.

How can you incorporate zone 2 training into your daily routine?

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

1. Duration and frequency: Start with two to three 30-minute sessions per week. As you progress, you can increase to four to five sessions of 45 minutes each. The goal is to spend a total of three to five hours per week in Zone 2.
   
2. Activities: Suitable activities include cycling, brisk walking, swimming or running. For beginners, brisk walking on a slight incline can also be ideal. Use equipment such as exercise bikes or treadmills to keep the intensity consistent.
   
3. Intensity check: Use the “conversation test” to make sure you're in zone 2. You should still be able to talk, but it should feel slightly exhausting. You can also monitor your heart rate – it should be between 70 and 85% of your maximum heart rate. With the appropriate apps, you can view the range during your workout.
   
4. Stay consistent: the benefits of zone 2 training are realized over time. Consistency is key to achieving long-term results and strengthening your mitochondrial health.

Legs versus arms: why the leg muscles matter

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 use 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 the “fast-twitch” fibers, which have a lower mitochondrial capacity. This means that they produce lactate more quickly and reach the training limits of zone 2 earlier. To get the best results for your health span, 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 basis for metabolic health. Studies have shown that people with metabolic diseases are barely able to utilize fat efficiently. Regular zone 2 training 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 mitochondria – play a crucial role in healthspan.

2025: Your year for more zone 2

Imagine looking back at the end of the coming year and feeling the changes: more energy in your daily life, a more stable metabolism and the feeling of having 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 incorporate Zone 2 training into your daily routine? In the beginning, it may only be small steps – a walk after work, a relaxed bike ride at 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 a longer healthspan and thus greater longevity. Get started, find your rhythm, and make 2025 your year of change. You'll be surprised how much better you can feel – week after week, step by step.

Would you like to find out more about this?

• 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