Feeling Lightheaded During Workouts? Signs You Shouldn’t Ignore

From time to time, we’ve all pushed ourselves in the gym or during a run. But when that feeling of “I might faint” creeps in mid-workout, it’s your body telling you something’s off. While occasional lightheadedness can be harmless, repeated or intense episodes (especially with other warning signs) shouldn’t be ignored.

What Does “Lightheaded” Really Mean?

People often say “dizzy” when they really mean lightheaded. True lightheadedness feels like you might faint, while vertigo feels like the room is spinning, and dizziness has a more visual component. Most workout-related symptoms fall under the category of lightheadedness, often linked to blood pressure, hydration, or breathing.

Common Reasons You Might Feel Lightheaded

Several everyday factors can make you feel lightheaded during or after exercise. Most are manageable with a few adjustments.

• Dehydration: Losing too much fluid through sweat reduces your blood volume, making it harder for oxygen to reach your brain. Drink water throughout the day, not just before a workout.
• Low blood sugar: Exercising on an empty stomach can cause blood sugar levels to dip. Have a small snack, such as a banana or a piece of toast, beforehand.
• Overexertion: Pushing yourself too hard, too soon, can overwhelm your cardiovascular system. Build intensity gradually and listen to your body.
• Holding your breath: Many people unintentionally hold their breath during effort (especially while lifting). Try steady, rhythmic breathing instead.
• Sudden position changes: Standing up too quickly or transitioning from seated to standing position can cause a brief drop in blood pressure. Move slowly and give your body time to adjust.
• Medication or caffeine: Blood pressure medications, diuretics, or stimulants can affect how your body responds to exertion. Check with your provider if new symptoms appear after a medication change.

Red Flags You Shouldn’t Ignore

Lightheadedness isn’t always harmless. Stop exercising and seek medical care if you experience:

• Chest pain, tightness, or heart palpitations
• Fainting or near-fainting spells
• Shortness of breath or difficulty breathing
• Blurred vision, confusion, or slurred speech
• Persistent or recurring symptoms despite rest and hydration

In certain cases, lightheadedness during workouts can signal an underlying medical issue.

What to Do If You Feel Lightheaded

If you start to feel lightheaded during your workout:

1. Stop immediately and sit or lie down to avoid falling.
2. Elevate your legs, if possible, as this helps blood flow return to your brain.
3. Sip water or an electrolyte drink.
4. Have a quick snack if it’s been a while since you’ve eaten.
5. Breathe slowly and deeply until symptoms pass.
6. Call it a day, and consider consulting a healthcare professional if the feeling doesn’t go away quickly.

If symptoms persist, track their occurrence (including time of day, type of workout, and food intake) and share this information with your healthcare provider.

When to See a Physical Therapist

Feeling lightheaded once in a while isn’t unusual, but it shouldn’t be ignored. Often, small changes, such as  improved hydration, nutrition, or pacing, make a big difference. If symptoms persist or are accompanied by balance changes or dizziness, a physical therapist may be able to help.

Vestibular-trained therapists can assess balance, posture, and movement patterns while identifying other contributing factors that may impact these areas. They may also be able to design a safe, individualized plan to keep you exercising confidently and without fear of setbacks.

Listening to your body and seeking help when needed can keep your workouts both safe and enjoyable. If you’d like to learn more or feel you might benefit from working with one of our movement experts, schedule a free assessment to connect with a licensed physical therapist who can help.

*Per federal guidelines, beneficiaries of plans such as Medicare, Medicaid, Tricare, VHA and other federally funded plans are not eligible for free assessments.

The Athletico blog is an educational resource written by Athletico employees. Athletico bloggers are licensed professionals who abide by the code of ethics outlined by their respective professional associations. The content published in blog posts represents the opinion of the individual author based on their expertise and experience. The content provided in this blog is for informational purposes only, does not constitute medical advice and should not be relied on for making personal health decisions.

References:
1. Armstrong, Lawrence E. “Rehydration during Endurance Exercise: Challenges, Research, Options, Methods.” Nutrients, vol. 13, no. 3, 9 Mar. 2021, p. 887. PMC, doi:10.3390/nu13030887.
2. Dube, Athar, et al. “Effects of Hypohydration and Fluid Balance in Athletes’ Cognitive Performance.” Journal of Sports Science & Medicine, 2022. PubMed, https://pubmed.ncbi.nlm.nih.gov/36032481/
3. Gauer, R. L. “Evaluation of Syncope.” American Family Physician, vol. 84, no. 6, 15 Sept. 2011, pp. 640-646. AAFP, https://www.aafp.org/pubs/afp/issues/2011/0915/p640.html
4. Majtenyi, Cathy. “Dizzy after a Workout? Take a Drink, Says Brock Co-Led Research.” Brock News, 1 Apr. 2025, brocku.ca/brock-news/2025/04/dizzy-after-a-workout-take-a-drink-says-brock-co-led-research/.