Lightheaded and Working Out

Wednesday, November 10, 2021
Lightheaded and Working Out

I’ve had multiple clients mention they get lightheaded when doing resistance training and working out. Many of them have asked if it is normal or have a sense that something might be wrong. I thought it would be worth providing feedback on why this can occur and when it should be perceived as a problem.

First off, please understand I’m writing from my personal experience as a trainer and am in no way offering medical advice or a diagnosis. If you experience symptoms of dizziness while exercising, you should consult a medical professional.

At Body Basics we train clients ranging in age from teenagers to folks in their nineties. Regardless of age I’ve heard clients comment about getting lightheaded while lifting. Here are some of the reasons this can occur.

Having Atrial Fibrillation (AFib)

I’ve had clients with Afib that have had issues of getting lightheaded while working out. Sometimes their heartbeat would go out of rhythm. This can happen a couple of different ways, but the result is that their heart isn’t able to provide the oxygen their body needs. This is always a concern, and we immediately stop exercising until their heart calms back down and gets back in rhythm. It’s also important for us to know this prior to training a client so we can modify the program to accommodate this type of condition.

Being on medication that is designed to keep your heart rate low

Certain medications (including blood pressure meds) can have the effect of keeping your heart rate lower than it would normally be without those meds. If you put a demand on your body through exercise where it’s needing more oxygen than it’s able to get due to a suppressed heart rate, the affect is you will feel lightheaded until your body recovers. It’s important to modify your training program according to the medications you are on and consult your doctor prior to engaging in exercise or activity.

Doing HIIT workouts that exhaust your cardio system to the point you can’t get enough oxygen

Your body increases its heart rate for one primary reason--to get oxygen into the blood. The harder you work, the more oxygen your body needs. Anytime you increase the energy demand on your body through exercising certain muscles, those muscles deprive that localized area of the energy it has. By increasing your heart rate your body can get new blood filled with oxygen and energy back to those working muscles so they can perform the task you’re asking of them. Depending on how rapidly you move, you can get yourself to a state called your aerobic threshold. This is the maximum amount of energy your body can use provided through oxygen and blood. When you reach this limit and try to surpass that threshold you can experience light-headedness. Usually this can quickly be reversed by slowing down the rate at which you’re working.

Lifting heavy weight such as in a strength training program

When you lift extremely heavy weight (whatever is heavy for you), you will naturally build a lot of internal pressure. Anytime we create intense internal pressure, our blood pressure will increase. When you’ve completed a set, it is not uncommon to feel very light-headed or even black out as your blood pressure drops. This is not necessarily healthy to do at extreme levels such as the strong men competitors, but it is a reality of pushing your body to its maximum potential.

Low blood sugar or diabetes

If you are diabetic, you most likely are aware of what can happen to your body when your blood sugar levels are off. Stabilizing those first is very important before you begin exercising. Individuals can also experience low blood sugar symptoms without being diabetic. This is when your body doesn’t have enough glucose in its bloodstream, which can lead to dizziness plus blurred vision, excessive sweating, weakness, confusion, etc. Make sure you (diabetic or not) always listen to your body while exercising and feed it the proper nutrition before and after including drinking enough water.

Thyroid conditions or adrenal fatigue

More and more people these days suffer from a thyroid or an adrenal disorder. Because our bodies are usually over-stressed when managing either of these conditions, you want to make sure not to over-stress the body when working out. It is possible to exercise with either of these conditions. It can actually help if done strategically. Talk with your physician to see what type of exercise they recommend and find a personal trainer who is knowledgeable in this area.


It’s pretty simple… The more hydrated you are the more free-flowing your blood is within your body, which means that oxygen is also moving more freely through your body. If you are dehydrated, your blood will not be able to get to the tissues, muscles, and brain as quick as it needs, which can lead to dizziness and fatigue. Make sure you are properly hydrated even if you are not exercising. A good rule of thumb is trying to drink half you body weight in ounces daily.

There are many other reasons for lightheadedness that are not listed in this article including other disorders dealing with the cardiovascular system, nervous system, endocrine system, etc. Please keep in mind, if you already have a heart issue or high/extremely low blood pressure, you should talk to your doctor about which type of exercise is healthy and good for you. It is also important to have a personal trainer that is familiar with training clients that have various conditions such as these.

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