Zone 2 training in autumn: Why going slowly makes you faster
By Kurt Tropper · 7 October 2026 · Reading time: approx. 6 minutes
Images: @Jagdhof, AdobeStock@bnenin
Shortly after eight, the mist still hangs in the spruce trees. Nine degrees; his breath forms a mist in front of his face, and the man on the forest path is running so leisurely that a casual walker could almost keep up with him. He could go faster. He doesn’t want to. His watch has been showing almost the same heart rate for the last forty minutes, and that’s exactly the point. Zone 2 training is the most unspectacular way to build endurance, and probably the most effective. Anyone who starts this in autumn lays the foundations for everything they want to do at speed in the spring.
What Zone 2 training means and why it is so often done incorrectly
Most training models divide the intensity into five heart rate zones. Zone 2 lies just below the first lactate threshold, the aerobic threshold. Your body derives almost all its energy from oxygen, burns a large proportion of fat and breaks down lactate as quickly as it is produced. You’re challenged, but never out of breath.
The problem is rarely the body, but the mind. Many people run their easy sessions too fast and their hard sessions too slowly. They end up in a middle ground that leaves them tired but develops neither a base nor peak fitness.
What happens in your body when you exercise at a slow pace
The transformation takes place in the slow-twitch muscle fibres. Steady, prolonged exertion is the strongest signal for them to form new mitochondria – the cell’s powerhouses that convert fat and sugar into energy using oxygen. At the same time, fine capillaries grow. More mitochondria also utilise lactate more efficiently, your thresholds shift upwards, and you’ll be able to maintain a high pace for longer.
The heart adapts too: the left ventricle pumps more blood per beat, and your resting heart rate drops. And your muscles absorb sugar more easily. That is why Zone 2 features in almost every serious discussion about longevity these days.
How to find your Zone 2 without a lab
The simplest tool is your breath. In Zone 2, you can speak in full sentences, but you wouldn’t want to sing. A rough guide is 60 to 70 per cent of your maximum heart rate; a fitness assessment with lactate measurement provides a more accurate picture. If your heart rate rises significantly in the second half whilst maintaining the same pace, you were going too fast. A session of 45 to 90 minutes, two to three times a week, is recommended. The 80/20 principle stems from research involving top-level endurance athletes: around 80 per cent at an easy pace, and about 20 per cent at an intense pace. On hills, this sometimes means walking instead of running. That’s not a sign of weakness; it’s a method.
Why autumn is the best time for building up your basic endurance
The competitions are over, and the cool air is a relief. In hot weather, the body’s thermoregulation alone causes your heart rate to rise; read more about this at Training in hot weather. Moderate workouts are also kind to your immune system during the infection season, whilst very strenuous exercise can weaken your defences in the short term.
As the days get shorter, shift your base training to the gym: exercise bikes, treadmills or rowing machines work just as well. Add two short strength training sessions a week; they protect your tendons and joints. We explain which machines are best suited for this in Machines vs. Free Weights
Zone 2 in the altitude chamber: What hypoxia training changes
At altitude, every breath contains less oxygen. Your body reacts immediately: your heart and breathing have to work harder, even at low intensity. For Zone 2, this means that your pace drops significantly at altitude, whilst the strain on your body remains the same. If you base your training on pace, you’ll end up pushing yourself too hard. The key factors are your heart rate, breathing and how you feel. The benefit lies in the fact that the body responds to the lack of oxygen by making its own adaptations, such as in how the muscles utilise oxygen. You therefore gain an additional training stimulus with a lower mechanical load, which is gentler on your joints and tendons. It makes sense to start cautiously with moderate simulated altitude and shorter sessions of 30 to 45 minutes. Anyone with heart or lung conditions should consult a doctor before starting hypoxia training. You can find more background information in our article on hypoxia training.
Basic endurance training in the Bavarian Forest: the Jagdhof as a training ground
The Wellness & Sports Hotel Jagdhof is a five-star hotel in Röhrnbach in the Bavarian Forest, between Passau and the Bavarian Forest National Park, featuring a 1,380-square-metre sports and fitness area and two altitude chambers. These simulate altitudes ranging from 1,500 to 8,500 metres. For Zone 2, the lower settings are sufficient; the hotel team will help you adjust them.
Outdoors, guided e-bike tours and hikes take you through the woods. The terrain is hilly, so the ‘walking rule’ applies particularly when going uphill. If it rains, the gym has a cardio area with Technogym equipment for a quiet hour on the ergometer.
Afterwards comes the part your body needs to adapt: 7,700 square metres of wellness and aquatic facilities, featuring eleven themed saunas, a 20-metre indoor pool and a 25-metre infinity pool heated all year round.
Perhaps that is the real challenge of Zone 2: not the exertion, but the restraint. Those who learn to take it slow in autumn will enter the new year with a foundation that no interval training can replace.
FAQ SECTION on Zone 2 training
What is Zone 2 training?
Zone 2 training is endurance training just below the first lactate threshold. The body derives almost all its energy from oxygen and utilises a large proportion of fat. The intensity is moderate; you can still speak in full sentences whilst doing it.
How can I tell if I’m training in Zone 2?
Using the talk test: you can speak in full sentences, but you can no longer sing. As a rough guide, aim for 60 to 70 per cent of your maximum heart rate. A performance assessment with lactate measurement provides a more accurate picture.
How often and for how long should I train in Zone 2?
Two to three sessions per week, each lasting 45 to 90 minutes, have proven effective. In line with the 80/20 principle, around 80 per cent of endurance training is carried out at a moderate intensity.
Can I also train in Zone 2 in the altitude chamber?
Yes. At simulated altitude, your pace slows down whilst your heart rate remains the same, so you should focus on your heart rate and breathing rather than your speed. Start with moderate altitude and shorter sessions. If you have a heart or lung condition, consult your doctor first.
Why is autumn ideal for building up your basic endurance?
There are hardly any competitions; the cool air keeps your heart rate more stable than in summer, and moderate exercise supports the immune system during the infection season. This lays the foundations on which more intensive training can be built in the spring.