High-Intensity Interval Training: Run Until You’re Out of Breath
Sometimes you start running until you’re gasping for air, then slow down again. Researchers are now studying this exact kind of training.
1. What Is It, Actually?
In high-intensity interval training, fast and slow phases alternate. The long name translates to: training with very strenuous short sections. You know this from playing. You sprint as fast as you can until you can barely breathe. Then you walk a bit and take deep breaths. After that, you sprint again. The word interval means the gap between the fast parts. In high-intensity interval training, the fast part is truly fast. You can barely speak during it. Your heart pounds, your legs feel warm, and you clearly notice how hard you are working. Important: This is not a substance or a tablet. It is a way of moving. You can do it while running, cycling, swimming, or climbing stairs. There is no powder or juice to swallow for it. Some people do just a few minutes of it. Others take longer pauses in between. How much of it is good depends on the individual. Researchers are still investigating this.
2. Where Does It Come From?
You do not need to buy or look for this training. It is already part of your day. Think of the schoolyard. When playing tag, you sprint in short, wild bursts. Then you stand there panting and laughing. That is exactly this pattern: fast, pause, fast. Or think of stairs. You take two steps at once, and when you reach the top, you take a deep breath. Then you walk calmly again. Even animals do this. A dog races across the meadow and then stops, tongue hanging out. Seen this way, it is nothing artificial. It is how children and animals move when they play. Researchers examine this pattern more closely and record what happens in the body.
3. What Are Researchers Investigating?
Researchers have many questions about this training. In studies, people were asked to do short fast sections followed by steady running. Afterwards, the researchers asked which they enjoyed more. In one study, participants said the short fast sections gave them more pleasure than steady training. Other studies looked at the body. One examined how training affects gut bacteria. Another looked at heart and metabolism in adult men with high body weight. Yet another showed that people respond very differently to the same training. Some get stronger quickly, others hardly at all. What remains open: How many fast sections are right for whom? How long do the changes last? And why do people respond so differently? These are testable questions that are still being worked on.
4. An Experiment to Think About
Imagine two friends. Both want to run for ten minutes. The first runs ten minutes steadily, fast enough to still hold a conversation. The second runs four half-minute sprints with one-minute walking breaks in between. Ask yourself: Who is more tired at the end? Who laughed more? Who would rather do it again tomorrow? You can try this yourself without a watch. Sprint to the next lamppost as fast as you can. Then walk slowly until you are breathing calmly again. Then sprint once more. Count how many times you can do this without feeling unwell.
For adults and professionals: the detailed page on High-Intensity Interval Training (HIIT)
Frequently Asked Questions
Do I have to do this in a club?
No. You can do it while playing tag, climbing stairs or riding your bike. The important thing is that you feel comfortable doing it.
Why do I have to breathe so fast during this?
Your muscles need much more air when you run fast than when you walk. That’s why your heart beats faster and you breathe in and out deeply. When you slow down, your breathing becomes calm again.
Is running fast better than running for a long time?
It’s not that simple. In the studies, people reacted very differently, and researchers are still checking who benefits most from which approach. Both can feel good.
Every statement on this page carries its evidence tier — proven, plausible or hypothesis — and leads to the original work. The decision in the individual case rests with the practitioner; we provide the connections.