Is it okay to feel lightheaded and dizzy after physical activity?

1) Dear Alice,

Light-headedness when I stop running:

When I do a 3-mile or 5-mile run, I run for time and try to finish with nothing in the tank. The closer I get to the end, the more I push myself, because I know I don't need to sustain the effort much longer. When I stop running, I suddenly get very light-headed and dizzy. It never happens while I'm running. I walk briskly while I'm warming down, but that doesn't prevent it. Why does this happen? Is it dangerous?

2)  Dear Alice,

Sometimes after jogging a while, or cycling a great distance, my head begins to spin and I feel as if I'm going to pass out. Is it normal to have feelings like these, and if so, how intense should these feelings be?

P.S.: your forum is a very helpful resource when a problem occurs in my life. Thank you for your continuing, inspiring, helpful answers to a lot of life's little (and some not so little) questions.

Dear Reader 1 and Reader 2,

Thank you for coming here — glad to help with any health concerns that may be running through your minds! As you both may already know, physical activity causes the heart to work faster, increasing the rate at which it pumps blood through the body. Abruptly stopping your activity (especially without cooling down) may cause a sudden drop in blood pressure, which may be the culprit behind feeling dizzy or faint. Luckily, there a few options to help with this, but it’s always a good idea to pay attention to your bodies as low blood pressure may be a sign of a more serious medical condition.

Some key factors contribute to lower blood pressure after a sudden stop in physical activity. While working out, the heart pumps oxygenated blood at a faster rate than typical to reach active muscles, and the muscles help squeeze deoxygenated blood through veins back to the heart. Blood vessels in the skin also expand to dissipate heat. When physical activity ends abruptly, the heart and muscles both slow down their rates while blood vessels may remain dilated. As a result, blood may stay longer in the lower extremities, returning to the heart (and subsequently the brain) at a slower rate. This drop in blood pressure may potentially make someone feel dizzy, lightheaded, or even faint.

If either of you find yourself feeling faint, you can try a few different strategies. One option is to place your head between your knees while sitting down. Another is to lie down so your head is level with your heart. Blood flow to the brain then increases, causing the feeling of faintness to stop. To help limit or prevent feeling dizzy or lightheaded after physical activity in general, cooling down adequately is key, coming to a full stop only after gradually decreasing activity. Slowing down in this way helps maintain heart rate and circulation by gradually reducing them. In your case, Reader 1, you already warm down before being still, but perhaps walking briskly is too sudden a decrease in movement; jogging slowly at first before dropping down to a brisk walking pace may do the trick. Reader 2, if you're not warming down, you may want to try slowly decreasing your activity before stopping completely. If, however, this more incremental reduction in activity doesn't improve how you feel after a run, or if this is a new development, it's probably best to make an appointment with a health care provider for a check-up and consultation.

It’s common for someone to feel lightheaded or dizzy when they abruptly stop arduous physical activity. However, if a person feels lightheaded or faints during physical activity, that may indicate a serious medical condition. It’s recommended that they stop and seek medical attention. Some conditions that may cause low blood pressure include:

  • Certain heart conditions
  • Dehydration
  • Blood loss
  • Lack of nutrients in the diet
  • Endocrine problems (such as low blood sugar)

List adapted from Mayo Clinic.

Just as warming up helps prepare the body for physical activity, warming down helps prepare the body for rest, so taking the time to slow down may help prevent these dizzy or faint feelings. Hope this helps!

Last updated Dec 29, 2017
Originally published Feb 20, 2004

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