What Does It Mean When You Get Lightheaded From Running on the Treadmill?

If you find yourself feeling dizzy during your treadmill run, it may be due to underlying problems.
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If you feel lightheaded or dizzy during or after a run on the treadmill, don't ignore it. It may be caused by something simple that takes a quick fix like replenishing fluids, but it may also be a sign of a more serious underlying problem. Either way, it’s important to know why this feeling may occur and how to prevent and relieve it.

High Blood Pressure

    Your heart rate is constantly adjusting during your workout and depends on the type and intensity of the exercise. Blood pressure can spike if your body is put under a large amount of physical strain, causing dizziness, lightheadedness and breathlessness. This usually happens when you change the intensity of your workout quickly. For example, if you were jogging at a moderate pace on a flat treadmill and you increase the incline by a large percentage, your blood pressure may spike because of the sudden physical strain. This spike in blood pressure, also known as exercise hypertension, may be an early sign of cardiovascular disease. Overexertion, or pushing yourself too hard during a workout, can also lead to lightheadedness.

Dehydration or Poor Nutrition

    Another reason you may experience lightheadedness during or after your treadmill workout is poor nutrition. Remember to stay hydrated before, during and after your workout. MayoClinic.com recommends 2 to 3 cups of water during the two to three hours before exercise, 1/2 to 1 cup every 15 to 20 minutes during exercise and 2 to 3 cups after exercise for every pound you lost during your workout. Eat large meals at least three to four hours before exercise, small meals at least two to three hours before and small snacks the hour before. Consider healthy snacks like nuts, fruit, and granola bars to keep up your blood sugar throughout your workout, the site recommends.


    Another reason you may experience lightheadedness while running on the treadmill is low blood sugar, a condition known as hypoglycemia. Blood sugar is the amount of glucose in your blood at any given time, and low blood sugar can result in lightheadedness as well as fatigue, excessive sweating and blurred vision. Exercising with a low blood sugar level is dangerous and can lead to more serious side effects such as seizures and coma.

What to Do If You Feel Lightheaded

    If you begin to feel lightheaded during your workout, decrease the intensity or take a short rest until the sensation subsides. Make sure to remove yourself from any potentially dangerous situations in case your lightheadedness leads to blurred vision or faintness. If you are on the treadmill, push the emergency red stop button and step down. Find a place to sit and rest. Call for help if the symptoms do not subside or they worsen. If you regularly experience lightheadedness during exercise, check with your doctor, who can test you for any underlying conditions like diabetes or cardiovascular disease.

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