Why People Pass Out From Deadlifts? (4 Reasons & How to Avoid)

We’ve all seen that video of someone going for a max deadlift, getting close to lock-out, then passing out and falling backward. Rest assured, this is not normal, and passing out can be entirely avoided once you know the reasons why it happens.

So why do people pass out from deadlifts? There are four reasons that explain this phenonemon:

  1. Not Breathing Properly
  2. Low Blood Pressure
  3. Taking Too Long To Set Up
  4. Lifting With Low Blood Sugar

Let’s cover each of these points in more detail so you understand how to perform the deadlift without feeling light-headed or passing out. Keep in mind, if you’re passing out from deadlifts you’ll want to treat it seriously and seek medical attention to ensure there are no underlying issues.

Terminology: Syncope

Syncope is the medical term that refers to the temporary loss of consciousness that usually relates to a lack of blood flow to the brain.

Disclaimer: fainting should be treated as a medical emergency until the cause is known. But most often, syncope usually isn’t harmful nor means you have any serious problem.

Many nerves connect with your heart and blood vessels, and fainting occurs when the heart can’t pump enough oxygen to the brain. This happens while deadlifting because blood is rushing to your muscles to produce maximal force.

With that said, there could be several reasons why lifters pass out when deadlifting, and for the healthy individual there are usually four main causes.

1. Not Breathing Properly

When you breathe in the deadlift you want to implement the valsava maneuveur.

This method of breathing refers to taking a big inhalation into your belly, holding your breath, and then forcefully pushing out. When you ‘push out’, you are still holding your breath, but mimicking what it would feel like if you were going to exhale.

We cover how to breath properly in the deadlift elsewhere, but this kind of breathing can take hundreds of pounds of load off the spine while lifting (Hukins et al, 1990). This is because the valsava maneuver creates ‘intra-abdominal pressure’, allowing your core to be stabilized as if you were wearing a weightlifting belt.

During the valsava maneuver, your blood pressure rises. Once you’ve finished the lift, your blood pressure decreases, often below baseline before rising again and returning to normal. The rising and falling of blood pressure can happen quickly, and it’s the sudden drop in pressure that can make you feel light headed.

So while the valsava maneuver has extreme benefits in allowing you to lift more weight, you need to ensure that:

You’re holding your breath too long

When you perform the valsalva maneuver, as soon as you feel your core engaged you should be pulling the weight off the floor. The longer you hold your breath, the more time your brain is going without oxygen. You also don’t need to hold your breath throughout the entire movement. A good practice is to breathe out through your sticking point.

Here’s an example of an athlete holding their breath too long:

You can learn more about why powerlifters hold their breath in my other article!

Releasing breath too fast

As I mentioned, your blood pressure rises while performing the valsalva maneuver, but as you breathe out, your blood pressure decreases. This is normal because you want your blood pressure to return back to baseline. However, if you breathe out too quickly, there will be a sharp decrease in blood pressure, often overcompensating and temporarily falling below normal levels. This is often the case when you see someone pull a big deadlift, and they start screaming with excitement and letting out their air rapidly. Try to remember to breathe out as controlled as you can once the lift is over.

Here’s an example of a lifter releasing their breath too fast after they finish the pull:

Want to improve your deadlift technique?

2. Low Blood Pressure

While I mentioned that the valsalva maneuver can cause a sharp decrease in blood pressure after letting your air out too quickly, there may be other reasons for low blood pressure. For example:

If you’ve been sitting too long

If you sit too long and then stand up your blood usually pools in your lower extremities, which can cause a decrease in blood pressure. Before attempting a max deadlift, you want to ensure that you’ve been standing or walking around for a minute or so to avoid this issue.

This was also one of the factors discussed in my other article on why powerlifters get nosebleeds when deadlifting.

If you’re dehydrated

Powerlifters who compete may have to reduce their water intake in order to make a weight class. If athletes don’t have a proper hydration plan following their weigh-ins, then being dehydrated while trying to compete can lead to dizziness. A general rule of thumb is to consume 16-20 ounces per lb of bodyweight lost during/after training. 

If you experience low blood pressure, you could carry salt tablets to put in your water. Salt will temporarily increase your blood pressure.

If you’ve consumed alcohol or taking medication

Alcohol has been shown to reduce blood pressure, so if you were out drinking the night before then decided to go to the gym and deadlift heavy, you might feel lightheaded. Additionally, take note of any medications that you’re on and see if they have side-effects of causing low blood pressure. While you might not feel the impact of low blood pressure during your everyday life, lifting heavy might cause a negative response.

Sometimes when powerlifters sniff ammonia it can help prevent them from passing out while lifting.

3. Taking Too Long To Set Up

You’ll notice that some lifters hold the bar for a long time before actually initiating movement.

When you’re bent over holding onto the bar, blood will rush to your head. When you start pulling to stand erect, the blood drains from your head to facilitate oxygen to your leg and back muscles.

This is normal, but what you want to avoid is being bent over for too long where all of your blood goes to your head and then quickly needs to rush to your muscles to facilitate the movement. This effect would be compounded by the valsalva maneuver, and some of the other mistakes already discussed like holding your breath too long or breathing out too quickly.

Here’s an example of a deadlift set-up taking too long:

Similar to passing out while deadlifting, the front squat can choke you causing you to feel lightheaded. Check out my other article that discusses this in more detail.

4. Lifting With Low Blood Sugar

If you train or compete while having low blood sugar then you might be at a greater risk of passing out during deadlifts.

You may have low blood sugar if you train fasted or use a low carb diet. Powerlifters who compete often have to reduce their food consumption and carb intake leading into a competition if they have to make a specific bodyweight category. For every 1 gram of carb consumed, there are approximately 2-3 grams of water retained. Therefore, athletes often reduce carbs as a weight cutting strategy leading into competition.

Possible warning signs that you have low blood sugar is if you start shaking or sweating (more than usual), or you feel weak. I always like to carry something sugary in my gym bag in case this happens. Some athletes use sugar pills to quickly return their glucose levels to baseline.

Final Thoughts

The most common cause of fainting while deadlifting is not implementing the valsalva maneuver correctly. While it has its benefits of being able to lift more weight, you’ll want to make sure you practice it correctly. With that said, if you’re passing out while deadlifting, you’ll definitely want to seek a medical professional to see if there are any underlying issues.

Feature image from @apemanstrong Instagram page. 

What To Read Next

Proper Breathing In The Deadlift: How to Set Up & Take 100s of Pounds of Pressure Off Your Spine


Hukins DWL, Kirby, MC, Sikoryn, TA, Aspden, RM, and Cox, AJ. Comparison of structure, mechanical properties, and functions of lumbar spinal ligaments. Spine 15: 787–795, 1990.