5 Reasons Why You May Feel Dizzy After Working Out

Have you ever been working out and all of a sudden feel a wave of dizziness or lightheadedness rush over you to the point where you feel the need to sit down? If you’ve wondered what could be causing this sudden disorientation and aren’t quite sure why it happened, you’re in luck! In this article, we’ll be going over seven of the more common reasons why you might experience dizziness or lightheadedness at the end of your workout, as well as two medical reasons that may be an underlying condition that you’ll need to speak with a medical professional about. We’ll also discuss potential solutions for each reason in order to either prevent or be aware of why you may be experiencing dizziness or lightheadedness. Let’s begin! 

1. Overexertion

One of the reasons people may experience bouts of dizziness and lightheadedness is due to overexertion. When you push yourself harder than your body is used to, you may feel dizzy, faint, lightheaded, thirsty, or nauseous to the point where you actually vomit. Nearly 36% of injuries related to overexertion happen within a fitness facility (gyms or exercise classes) and can occur during or after you’ve finished a particularly strenuous activity. 


Solution: Your trainer is responsible for observing you to ensure you’re doing the correct amount of reps, weight, and sets. If at any point you feel dizzy or lightheaded, let your trainer know immediately. Of course, you shouldn’t use this as an excuse to get out of completing your reps or quitting early. Your trainer will encourage you to take a minute or two to rest as well as to take slow deep breaths. Once you feel the dizziness/lightheadedness pass, your trainer will continue to observe you for both safety and proper form. 

2. Using Machines of Continual Motion 

You may also experience dizziness or lightheadedness depending on the type of exercise you’re doing. Machines of continual motion, such as a treadmill or elliptical machine, may trick your mind into thinking you’re moving when you’re actually stationary. The moment you step off the machine and onto solid ground again, you may feel a wave of dizziness as your mind rapidly realizes you aren’t moving anymore. The official term for the mind feeling like you’re moving when you’re stationary is called “vertigo.” You may also experience a form of motion sickness by using machines of continual motion for an extended period of time. If you've ever traveled by boat and watched the waves crash into the side while your brain realizes your feet are still firmly planted on the ground, you know all too well how fast that sensation of dizziness sets in. 


Solution: If you start to feel dizzy or lightheaded while operating a machine of continual motion, it’s strongly encouraged to reduce your speed and hold tightly onto the side rails. You may also want to stop using the machine entirely, but just make sure it’s a gradual reduction of speed rather than an abrupt cessation. Try standing in place on the machine until the dizziness/lightheadedness fades. To avoid injury from falls, it’s crucial to avoid walking around or driving until that feeling of dizziness/lightheadedness goes away entirely. 

3. Dehydration

Dehydration is the result of losing more water than your body takes in (i.e, when you sweat more water than you drink). Your body is more prone to dehydration during hot weather, but can also occur from strenuous cardio and intense workouts.. You can also experience dehydration from minor illnesses, which is why when you’re sick, they often keep you on a liquid-based diet like soups/broths, natura/unsweetened fruit juices, water, etc. A good determining factor of your body’s overall hydration is to check the color of your urine (it should be a pale yellow).

Dehydration is far more common than it should be, due to the unfortunately ample supply of sugary beverages and juices. Contrary to popular belief, feeling thirsty isn’t simply an indication of dehydration coming on…thirst indicates you’re already dehydrated! Other common symptoms of dehydration include dizziness/lightheadedness, dry mouth, infrequent urination, fatigue, weakness, and feeling faint. 


Solution: If you feel that your dizziness/lightheadedness is caused by dehydration, you’ll need to replace the fluids and electrolytes right away. Coconut water is an excellent source of electrolytes and the unsweetened versions have a wealth of health benefits. Try to avoid energy/sports drinks, soft drinks, sweetened fruit juices, and other beverages with a high sugar content. Consider an OTC oral rehydration solution if you feel extremely dehydrated. Try to opt for beverages slightly below room temperature rather than completely chilled; the colder the drink, the harder your body has to work to warm it to a temperature that your body can use. 


Additionally, it’s crucial that you stay hydrated about half an hour before your workout (preferably with 8 oz. of water) and every 15 minutes during your workout (about 4 oz. each time). Remember that drinking smaller amounts of fluid consistently is more beneficial than a large amount in one sitting.

4. Lack of oxygen

One of the most challenging aspects of working out is not what you might think. It’s not the amount of reps you do, nor the amount of weight you do…it’s your breathing! Breathing properly is crucial to prevent feeling lightheaded or dizzy. Here’s why: as you work out, your muscles need a lot more oxygen than normal. Your heart rate increases, more blood is flowing, you’re sweating, and your muscles flex and tear as you work them. It’s very tempting to hold your breath until the exercise, or drift into irregular breathing as you focus on finishing your final rep/set. However, if you’re not breathing properly or only taking short gasps of air to tide you over, you’re severely limiting the amount of oxygen that can reach your brain. Feeling dizzy or lightheaded is the brain’s way of letting the body know that it’s oxygen-starved and needs more before continuing. 


Solution: During your sessions with your personal trainer, you’ll often hear a command to “breathe” rather than holding it in. Not only to breathe, but “exhale on the up” or “don’t hold your breath” or “exhale when you push.” Focusing on your breathing might be a momentary distraction, but it’s important to consciously practice your breathing rhythm to avoid feeling lightheaded. If you do feel lightheaded after a particularly strenuous workout, be sure to take slow deep breaths rather than gulping air through your open mouth. Breathe in through your nose and exhale through your mouth. 

5. Low blood sugar

Low blood sugar, also called hypoglycemia, is what happens when the amount of glucose (read: sugar) in your blood drops to very low levels. Sugar is what your body uses for energy, and the amount of glucose your body burns skyrockets as you work out. If you start to feel dizzy or lightheaded during or after a workout, low blood sugar may be the culprit. Some common symptoms of hypoglycemia also include clumsiness, hunger, irritability, shaking, fatigue, sweating, and anxiety. This may be particularly true if your workouts start before your workday (i.e., within the first hour of waking up). If you fall into this category, you may not feel like your stomach has woken up fully to the point of feeling hungry. As you exercise, your glucose levels drop before you can replenish them with a meal, thus leading you to feel many of the symptoms of low blood sugar. 


Solution: Eat something! If your workouts are first thing in the morning, you may not feel hungry at all even as you walk into your training session. You may brush it off and make an absentminded mental note to eat once you finish your session and head to your next appointment, but more often than not, you won’t end up eating until midday. If eating a full-blown meal first thing in the morning isn’t your thing, try keeping a small carb-rich snack nearby (i.e, a banana or handful of dates). Many workout enthusiasts opt for a pre-workout shake or a pre-made smoothie that they can chug on their way to the gym. Try to keep some fruit juice on hand If you start feeling waves of dizziness or lightheadedness come on. Once your workout is complete, it’s strongly encouraged to eat a meal or snacks that contain whole-grain and protein, thus preventing the impending blood sugar crash. 

Medical Maladies

Up to this point we’ve mentioned some of the more common reasons why you may experience dizziness or lightheadedness after working out. The majority of them had easy fixes or simple preventative measures. These next four are a tad more serious and usually require a medical diagnosis, discussion, and/or treatment. If you currently have any of these issues (or it runs in your family medical history), be sure to let your trainer know right away so your workout routine can be safely tailored to your needs. 

1. Low blood pressure

Blood pressure is defined as the measurable force of your blood as it pushes against the walls of your arteries. The optimal blood pressure reading is 120/80 millimeters of mercury (also displayed as mm Hg). Those with low blood pressure, called hypotension (not to be confused with HYPERtension) will display a reading of 90/60 mm HG or less.  


As you exercise, your blood pressure will drop to its lowest after about an hour. Those with low blood pressure may experience fatigue, blurred vision, nausea, loss of concentration, and even faiting. While it’s common for blood pressure to drop after vigorous workouts, it can also be triggered by various everyday activities. One example would be standing up too quickly or jumping out of bed too fast. You are also more prone to hypotension during pregnancy, pre-existing heart problems, and dehydration. Be sure to consult your primary care physician prior to engaging in any strenuous lifestyle changes, such as weight-lifting, marathon training, boxing, etc.

2. Heart arrhythmia

Heart arrhythmia is exactly what it sounds like: an abnormal rhythm of the heart (read: heartbeat). Heart arrhythmias are responsible for the heart beating slower than necessary, beating irregularly, or beating too fast. Emotional stress and pre-existing heart conditions (such as heart disease) can trigger arrhythmias, but exercise can actually make them worse. Arrhythmias don’t also present in symptoms, but there are several that you should be aware of: shortness of breath, dizziness, lightheadedness, heartbeat changes, sweating, and even fainting. You’ll notice that many of these symptoms may already present after a strenuous exercise, but you should pay attention to how your body reacts if any of these symptoms seem more intense than you feel they should be. Speak to your trainer if you feel that something’s not right; if you already know you  have heart arrhythmias, be sure to consult your primary care physician and your trainer before embarking on any strenuous training sessions. 

3: Orthostatic Hypotension

Similar to traditional hypotension, orthostatic/postural hypotension can bring on bouts of dizziness after you’ve completed an exercise that requires a good bit of getting up and getting down from a seated or lying down position. When you suddenly change your body’s position (either from standing to sitting), you may feel a rush of dizziness, lightheadedness, or even vertigo as your blood pressure drops. This change is especially true with any core workouts or chest presses that require you to suddenly change your body’s position. While it’s important to consult your doctor if you feel that you may indeed have orthostatic/postural hypotension, sometimes keeping well-hydrated or upping your sodium intake can help ward off any sudden changes to your blood pressure. Additionally, you can always train yourself to sit/stand up slowly and be more mindful of your body’s present static state to limit the frequency of low blood pressure changing rapidly. 

4. Certain Medications 

Modern medicine continues to be a marvel, but almost every medication has some side effects. These side effects may be exacerbated with exercise, namely lightheadedness or dizziness. Beta-blockers, hypotensive medication, some anti-depressants and stimulants, and seasonal allergy medication with antihistamines are all examples of medications that might make you feel dizzy or lightheaded during or after your workout. However, if you do start feeling more frequent bouts of dizziness or lightheadedness, don’t arbitrarily decide to stop taking your medications. Speak with your prescriber to see if there’s an alternate medication you can take that may have fewer side effects. 

When Medical Attention Is Required

The majority of dizziness and lightheadedness is felt during or directly after working out and tends to subside fairly quickly once your workout is complete. If the symptoms continue to pose a problem or keep happening despite your preventative actions, it’s strongly recommended to consult your primary care physician. Underlying medical issues like diabetes, pregnancy, loss of consciousness, confusion/disorientation, severe dehydration and hypoglycemia, extreme fatigue and inability to keep fluids down may be indicators that something else is wrong. Let your trainer and your primary care physician know if you experience any of these symptoms or if your gut feeling is telling you something is wrong. 

Closing Tips to Prevent Dizziness/Lightheadedness

If you’re new to working out or haven’t exercised regularly in a while, you’ll most likely experience lightheadedness or dizziness as some points. Here’s some tips to avoid feeling less than your best while working out. 


First and foremost, don’t overexert yourself. The world’s strongest man didn’t suddenly wake up one day and lift that great weight up without proper training. Your trainer will most likely start out with low weights, low reps, and a total body workout to determine how to properly approach your training sessions. As you build up your stamina and strength, your trainer will start to increase your weights, reps, and incorporate more difficult exercises for you to tackle. 


Secondly, it’s important to regulate your breathing technique. This might seem counterintuitive as you try to focus on lifting the heavy weight, but remember that your body needs extra oxygen as you exercise. Consider asking your trainer to incorporate yoga or pilates exercises, as these activities can encourage regulated breathing. 


Thirdly, try to eat and drink at least half an hour before your workout. Try to drink 8 oz. of water before your workout as well as a small snack to boost your blood sugar and ultimately your energy levels. Drink another 4 oz. every 15 minutes to stay hydrated until the end of your workout, and be sure to eat a protein- and carb-rich diet within an hour after you finish working out, unless stated otherwise by your nutritionist or primary care physician. 


Lastly, be mindful of any current or underlying health conditions you may have or ones that run in your family’s medical history. Paying attention to some of these symptoms can help you understand why you may be feeling more dizzy or lightheaded than usual. Speak with your trainer if you have any additional questions and remember to be as honest as possible. Your trainer is here to help you, sans judgment or prejudice. 


Working out can seem like this impossible mountain to climb, fraught with obstacles and setbacks. Yet it’s important to invest in yourself by taking steps to keep yourself as healthy as possible. There’s a reason they’re called “workouts”...they take work! But the work is rewarding, the challenges are enjoyed, and the results are worth that small hour you chisel out of your busy day. So what are you waiting for? Kick those excuses to the curb and come work out with us…you’ll be very glad you did!