Lightheaded After A Workout? Here’s Why You May Be Dizzy After Working Out

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If you nailed your workout, you likely feel proud and impressed with yourself. Unless you’re an exercise fiend, there’s also a good chance you feel relieved the workout is over.

It’s also completely normal and expected that you feel tired or like your muscles are spent after a hard workout.

But what if you feel lightheaded after a workout or running? Feeling dizzy after workouts is not particularly uncommon. 

While in most cases, feeling a little lightheaded after a workout isn’t a major cause for concern, it’s helpful to know the common causes of dizziness after exercise so that you can prevent feeling like the gym is spinning or you might pass out.

In this article, we will discuss why you may be dizzy after a workout and how to prevent feeling lightheaded after a workout, running, or another type of exercise.

We will discuss: 

  • Is It Normal to Feel Dizzy or Lightheaded After A Workout?
  • Why Do I Feel Lightheaded After A Workout? 6 Causes of Post-Exercise Dizziness
  • Why Do I Almost Pass Out After Running?
  • How to Prevent Lightheadedness After A Workout

Let’s get started!

A person feeling lightheaded after a workout.

Is It Normal to Feel Dizzy or Lightheaded After A Workout?

Feeling dizzy or lightheaded after a workout or high-intensity exercise like a tough spin class or HIIT session is fairly common, though it’s not necessarily “normal.”

We will discuss common causes of post-workout dizziness later on, but before we address why you might feel like you’re woozy or dizzy after exercise, let’s discuss the two primary types of dizziness you might feel during or after working out.

Lightheadedness With Exercise

Lightheadedness is often described as feeling like you’re going to pass out or faint. You might hear a high-pitched ring in your ears and feel a bit of an “out-of-body experience” such that you’re a little disassociated between your brain and body. 

If you are lightheaded while exercising or right afterward, you might also feel a little unstable. However, the room will not appear to be spinning.

If you lie down, the lightheaded feeling typically subsides.

A blurry image of a person and the woods.

Vertigo With Exercise

When you have vertigo after working out, your surroundings will seem to be spinning, even if you’re standing still or lying down.

With vertigo from exercise, you also often feel like you are tilting or feel off balance relative to your surroundings.

If vertigo continues after your workout, you may become nauseated to the point of vomiting.

Lightheadedness after a workout is usually less concerning than vertigo and should subside quickly, especially if you rest, refuel, and rehydrate.

On the other hand, vertigo after working out is more concerning, particularly if it is accompanied by additional symptoms such as changes in vision, confusion, and prolonged vomiting. 

If you are consistently experiencing vertigo after running or working out, you should speak with your medical provider as soon as possible.

Moreover, if you have an acute bout of vertigo after exercise that leads to severe vomiting and any additional symptoms like a bad headache, confusion, or vision changes, you should seek immediate medical care, as this can be a sign of a potentially life-threatening condition.

A person feeling lightheaded after a workout exhausted on the ground.

Why Do I Feel Lightheaded After A Workout? 6 Causes of Post-Exercise Dizziness

The following are some of the most common reasons for feeling lightheaded or dizzy after working out:

#1: Hyperventilating

When your brain is not getting enough oxygen, you can feel lightheaded, dizzy and may even have a transient sensation of vertigo.

One of the primary causes of relative oxygen depletion in the brain during exercise is using inefficient breathing patterns, such as hyperventilating.

Hyperventilating or not breathing deeply enough while running can cause dizziness and lightheadedness after running or working out.

When you overexert yourself and are running hard, it’s natural to start taking rapid breaths. 

Your mind tells you that the faster you breathe, the more oxygen you’ll get, but in reality, the converse is true.

Hyperventilating, or taking rapid and shallow breaths, is inefficient in terms of inhaling oxygen.

Slow, deep breaths actually bring in more oxygen for your body.

A person feeling lightheaded after a workout sitting down.

#2: Holding Your Breath

In much the same way that hyperventilating prevents you from getting enough oxygen, which, in turn, can cause you to feel lightheaded after running or working out, so too can holding your breath.

During difficult exercises, such as when you are trying to do squats or chest presses with a heavy load, some people forget to breathe because they’re just focusing on getting through the set.

If you hold your breath while you are working out, you’re not taking in any oxygen. This will lead to feeling lightheaded after a workout set is over.

Although it’s more common to accidentally hold your breath during strength training exercises than it is while running or doing other forms of cardio, it’s still quite possible that you’re not breathing enough during vigorous cardio or hard running intervals.

#3: Dehydration

Dehydration is often the reason you feel lightheaded after workouts, especially if it is hot out and you sweat a lot.

When you are dehydrated, your blood plasma volume drops. This effectively reduces your blood pressure because there’s less blood exerting force against your blood vessels.

Low blood pressure can lead to feeling dizzy or lightheaded, and running will exacerbate this feeling since your muscles and brain need additional oxygen while you’re exercising.

Low sugar written in sugar on a table.

#4: Low Blood Sugar

Although low blood sugar, referred to as hypoglycemia, is more common in athletes who have diabetes, it’s also possible for anyone to have low blood sugar during exercise if they have not fueled their body properly for their workout.

Low blood sugar is associated with symptoms such as dizziness, fatigue, cheekiness, irritability, and difficulty concentrating.

If you have low blood sugar during a workout, it is likely that you will feel lightheaded and weak during and after your workout until you refuel with carbohydrates.

If you feel like your nutrition plan is solid and you have fueled your body properly for your workout, yet you still think your blood sugar is dropping inappropriately, you should consult your physician to get lab work done.

It could be that you’re in a state of pre-diabetes or that you have some other metabolic issue that needs to be addressed.

A person feeling lightheaded after a workout, who has lay down in front of her computer.

#5: Orthostatic Hypotension

Postural hypotension, or orthostatic hypotension, can occur when you stand up too quickly, particularly if you are standing after lying down.

This can result in a sudden drop in blood pressure, which is associated with feelings of dizziness, lightheadedness, and even possibly vertigo.

Dizziness after exercise that occurs as soon as you stand up upon completing a chest press or some sort of reclined strength training exercise or after you have been down on a mat doing yoga or core exercises is often due to orthostatic hypotension.

Here, the solution is to sit up slowly and then gradually stand when you feel stable.

It’s also important to monitor your blood pressure, and if it’s chronically too low, you should work on hydrating more aggressively, particularly with electrolytes.

Sodium will help your body retain more water, which increases your blood volume and, thus, blood pressure.

A person holding their head feeling dizzy.

#6: Taking Certain Medications

Certain medications can cause you to feel lightheaded after a workout. 

Examples include antihistamines for seasonal allergies, certain antidepressants, beta-blockers, and other hypotensive medications.

If you have concerns that you might be experiencing side effects from your medications, speak with your healthcare provider about alternatives or best practices.

Why Do I Almost Pass Out After Running?

It’s fairly common to feel like you’re going to pass out after running, especially if you’re a beginner runner or have run too far or too fast.

This, again, usually comes down to hyperventilating while running, dehydration, or low blood sugar.

Iron deficiency can also lead to dizziness after running or other forms of exercise, so consider getting your ferritin levels checked.

A person hydrating.

How to Prevent Lightheadedness After A Workout

In most cases, with a little planning and preparation, you can avoid feeling lightheaded after exercise, allowing you to relish in just the afterglow of being done with your workout.

Here are some tips to prevent feeling lightheaded after running or other forms of exercise:

#1: Rethink Your Hydration

Dehydration is usually the most common cause of post-exercise dizziness.

Ensure that you are properly hydrated before, during, and after your workouts.

You should be drinking a minimum of 4-6 ounces of fluid every 15-20 minutes during exercise, and more so if it’s hot out or if you’re sweating a lot. However, do not exceed 800 mL per hour (about 27 ounces) without consuming the fluids with electrolytes and, ideally, in a 6-8% carbohydrate solution.

If you are exercising first thing in the morning, you are already starting out in a dehydrated state, so it’s crucial that you drink enough before your workout.

Electrolytes will increase your fluid absorption, and sports beverages with a little bit of glucose come further enhance the absorption of both the liquid itself as well as the electrolytes.

A bowl of oatmeal blueberries and almonds.

#2: Get Up Slowly

As mentioned, getting up too quickly after lying down can cause postural or orthostatic hypotension.

After doing exercises in a reclined position, make sure to sit up slowly and then gradually stand up.

#3: Have a Snack Before Your Workout

If you’re waiting too long after eating to do your workout, or if you are exercising first thing in the morning on an empty stomach, there’s a good chance your blood sugar is dropping too much during your workout, causing you to feel lightheaded and weak.

Make sure you’re having a carbohydrate-rich snack before endurance-based workouts or high-intensity workouts.

Exercising in a fasted state can definitely lead to feeling dizzy afterward.

On the other hand, if you’re eating too many simple sugars—such as fruit juices, sports beverages, and processed fruit snacks—before running or working out, your blood sugar might be crashing (reactive hypoglycemia).

Opt for snacks with complex carbohydrates and some healthy fats or protein to have a more stable release of glucose into your bloodstream.

Examples include a banana with peanut butter, hummus and crackers, or oatmeal with nuts.

A person running on the beach.

#4: Slow Your Breathing

Breathe slowly and deeply during exercise.

You may even benefit from breathwork exercises from yoga to work on your breathing.

#5: Don’t Hold Your Breath

Remember that holding your breath deprives your body of oxygen. Keep breathing throughout your workout, even when you’re pushing yourself!

#6: Slow Down

If you often feel like you’re going to pass out after running, slow your pace. You might be doing too much too soon for your current fitness level.

It’s important to restate that if you are regularly becoming dizzy or lightheaded after a workout or are experiencing a more significant bout of vertigo, you should speak to your healthcare provider as soon as possible.

Otherwise, try addressing some of these issues and see if you feel better.

For some pre-run snack ideas, check out our best snacks for runners.

A piece of toast with sliced banana and peanut butter.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, as well as a NASM-Certified Nutrition Coach and UESCA-certified running, endurance nutrition, and triathlon coach. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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