The question: Why do breathing exercises make me dizzy or light-headed?
The short answer: Light-headedness during a breathing exercise usually means you are moving more air than your body needs, which lowers carbon dioxide, and that can happen even when you breathe slowly. In a 2019 randomized study of 46 young adults, one instruction to avoid excessive deep breathing nearly halved the drop in exhaled carbon dioxide and reduced a symptom score that included dizziness. It was one short lab session in healthy young adults, and the instruction did not prevent the drop for everyone.
What the study did
Mikołaj Szulczewski at the University of Warsaw randomly assigned 46 young adults, ages 19 to 26, to one of two groups. Both breathed for 10 minutes at the same pace, guided by a sound cue: 4-second inhales and 6-second exhales, or six breaths per minute. One group also received the instruction to avoid excessive deep breathing and breathe shallowly and naturally. The other did not. The researchers measured end-tidal carbon dioxide, the carbon dioxide at the end of each exhaled breath. Participants rated dizziness, tingling, numbness, headache and muscle tension in the hands and feet, combined into one symptom score. Air hunger, task difficulty and mood were assessed separately.
What it found
Without the extra instruction, end-tidal carbon dioxide fell by an average of about 5.2 mmHg. With it, the average drop was about 2.7 mmHg. The instruction reduced the drop but did not eliminate it. The increase in the combined symptom score, which included dizziness, was also smaller in the instructed group. That was a difference in the combined score, not a separate demonstration that each symptom improved. The instruction did not significantly change air hunger or task difficulty and produced no clear advantage in mood. Some participants who received it still had substantial drops in carbon dioxide.
What it doesn’t show
The participants were healthy young adults with several health conditions excluded, and it was one short laboratory task, not a treatment trial or long-term training program. Missing recordings and questionnaires meant not every participant contributed to every analysis. The researchers did not measure breath volume, brain blood flow or oxygen levels directly. Broader physiology explains why over-breathing causes symptoms, but not every step of that explanation was measured here, and dizziness can have other causes.
Key points
- Slow and deep are different: slow is how often you breathe, deep is how much air moves with each breath.
- One instruction to avoid excessive deep breathing cut the average drop in exhaled carbon dioxide from about 5.2 to 2.7 mmHg at the same slow pace.
- Light-headedness and tingling reflect lowered carbon dioxide, not proof that a session is working or that something is being released.
Common questions
Can slow breathing still be over-breathing?
Yes. Hyperventilation means breathing more than the body needs relative to the carbon dioxide it produces. If you take fewer breaths but make each one as big as possible, you can still move as much air as fast, shallow breathing would. It does not have to look like panting.
Why does low carbon dioxide make you light-headed?
When you breathe out carbon dioxide faster than your body makes it, the level falls, which is called hypocapnia. One consequence is a narrowing of the blood vessels that supply the brain, which can reduce blood flow and contribute to light-headedness. Low carbon dioxide can also bring tingling and numbness.
Does feeling light-headed mean the practice is working?
No. Jesse Coomer explains that these sensations are a normal physiological effect of lowered carbon dioxide, not evidence of a better session or of releasing something. In a gentle practice like this one, dizziness is not the goal. A comfortable, unforced breath is.
What should I do if I feel dizzy during a gentle breathing practice?
The episode suggests sitting or lying somewhere safe and letting your breathing return to comfortable and unforced, rather than pushing through with repeated big breaths. Symptoms that persist, recur or happen outside practice deserve medical advice. Chest pain, fainting or new or severe breathlessness need urgent medical help.
Study cited: Szulczewski MT. An anti-hyperventilation instruction decreases the drop in end-tidal CO2 and symptoms of hyperventilation during breathing at 0.1 Hz. Applied Psychophysiology and Biofeedback. 2019;44(3):247-256. https://doi.org/10.1007/s10484-019-09438-y
Practice this: Coherence Breathing (4-6) to Calm Anxiety | 10 Minutes
Read the full transcript
Auto-generated from the video captions, so expect small errors.
Welcome back to the breathwork channel. My name is Jesse. This is decoding breath. And here is the short answer to the question. Repeated deep breaths can make you feel light-headed, especially if you're moving more air than your body needs, thereby lowering carbon dioxide. And you can do that while doing slow breathing, too. A randomized study found that one simple instruction, "Avoid excessive deep breathing." reduced the drop in exhaled carbon dioxide and the increase in a group of symptoms that included dizziness. That doesn't mean that it explains every case of dizziness, but it gives us something useful to work with. So, stay with me because the
difference between slowing the breath and engaging a breath can change how you approach your next practice. This is decoding breath. We take peer-reviewed breathing research and translate it into mechanisms and limits, not just a bunch of protocols. So, today we're looking at a familiar problem. You start a breathing exercise to feel better, but a few minutes later you're light-headed, tingling, or wondering if something is going wrong. Why do I feel strange? And it's tempting to assume that the sensation means the exercise is specially powerful. But before attaching a meaning to it, let's look at the breathing itself and what you might be doing. There are
two things people often combine in the instruction "Take a deep breath." Slow describes how often you breathe. Deep describes how much air moves with each breath. Those aren't the same thing. If you reduce the number of breaths, but make each one larger, you can still move the same amount of air as if you were hyperventilating with small breaths. Hyperventilation doesn't have to look like someone panting. It means ventilation is excessive relative to the body's production of carbon dioxide. Your body continuously produces carbon dioxide, and breathing carries it out of the system. And if you remove it faster than it's being produced, the level falls, and
that's called hypocapnia. One consequence is a narrowing of blood vessels supplying blood to the brain, which can reduce cerebral blood flow and contribute to lightheadedness. Changes associated with low carbon dioxide can also accompany tingling and a feeling of numbness. Those are physiological explanations, not evidence that you're releasing something or achieving some kind of better session. But, symptoms alone don't tell us your carbon dioxide level. Dizziness has other causes, and sensations during breathing aren't a home diagnostic test. That's one reason the measurement in today's study matters. In 2019, researchers from the University of Warsaw published a randomized experiment in Applied Psychophysiology and Biofeedback. 46 young adults
were assigned to one of two groups. Both groups followed the same breathing pace for 10 minutes. A sound cue guided 4-second inhales and a 6-second exhale. That's a six breaths per minute pace. The difference wasn't the pace or the ratio. One group received an additional instruction to avoid excessive deep breathing and to breathe shallowly and naturally. The other group didn't receive that instruction. The researchers measured end-tidal carbon dioxide, which is the carbon dioxide at the end of the exhaled breath. It's an exhaled gas measurement, not a direct measurement of blood flow inside the brain. Participants also rated symptoms including dizziness, tingling, numbness, headache, and muscle
tension in the hands and the feet. Those ratings were combined into a symptom score. Air hunger, task difficulty, and mood were assessed separately. Here's what happened. Without any additional instruction, end-tidal carbon dioxide fell by an average of about 5.2 mm of mercury. With the instruction, the average drop was about 2. So, the instruction reduced the drop, but it didn't eliminate it. Both groups were following the same slow rhythm, but the group reminded not to overdo the depth had a smaller change in the gas measurement. The increase in the combined symptom score was also similar in that group. This wasn't a separate demonstration that every individual
symptom improved. It was a difference in the combined score, which included dizziness. That's a useful result because the change was so ordinary. It wasn't a new breathing method, a device people needed to buy, or a more demanding pattern. It was a clarification about how much effort to put into the breath. Now, here's an important distinction. The instruction didn't significantly change reported air hunger or task difficulty. It didn't produce a clear advantage in mood, either. That means we shouldn't turn this into a claim that gentler breathing made everyone more relaxed or removed every uncomfortable sensation. It reduced the average carbon dioxide drop and the increase in
the measured symptom cluster. That's the result. It also didn't protect everybody. Some participants who received that instruction still had substantial drops in carbon dioxide. A helpful cue sometimes isn't a guarantee, and someone who's uncomfortable shouldn't assume that repeating the cue is all the help they'll ever need. So, what can you actually use? If you're going to do gentle breathing practice, don't automatically translate slow into fill your lungs as much as possible. The study supports being explicit about avoiding excessive depth, rather than doing whatever you feel in the moment. Think of the difference between allowing a comfortable breath and trying to perform an impressive breath. You
don't need to maximize the size of every inhale just because you're paying attention to it. And don't turn shallow breathing into a new competition to breathe as little as possible, either. The instruction in the study was about avoiding excessive deep breathing, not deliberately starving yourself of air. For your own practice, use this principle. It's just go for comfort. Go for unforced. If you become dizzy during voluntary exercise, stop the exercise and sit or lie somewhere safe. Let your breathing return to comfortable, unforced, rather than taking the repeated huge breaths to finish the session. That's safety guidance, not a diagnosis of what's causing the symptoms. If
the symptoms persist, recur, or happen outside of the practice, get medical advice. New or severe breathlessness, chest pain, fainting, it's not something to work through. It's not something to get advice in a video like this. Seek urgent medical help if that is the case. The study's limits are straightforward. These were young adults ages 19 to 26 with several health conditions excluded. It was one short laboratory task, not a treatment trial or a long-term training program. Missing recordings and questionnaires also meant that not every participant contributed to every analysis. The researchers didn't measure breath volume directly, brain blood flow, or oxygen levels. The broader physiology helps
explain why overbreathing can cause symptoms, but we shouldn't pretend that every step of that explanation was measured in this experiment. If you take one thing away, let it be this. Slower doesn't have to mean bigger, and dizziness isn't the goal when you're a follow a gentle breathing exercise. Avoid turning every inhale into a maximum breath effort. If you feel unwell, stop rather than treating the sensation as proof that something is happening. Here's my question for you. When someone tells you to take a deep breath, do you hear breathe comfortably, or do you hear fill your lungs as much as possible? Drop it in the comments
below. That difference in interpretation is worth paying attention to. And if you want the primary study I'm referencing, plus deeper breakdowns, I run a free circle community. Take a look at the links below and you can join us there. And here's what's coming next. Can breathing through your nose change how you remember something? A neuroscience study found that the timing of an inhale mattered during a memory task. The interest part wasn't simply more oxygen or more relaxation. Subscribe so you don't miss it. We the resources for this episode are below. We'll see you next time.