Headache After Working Out: Causes, Prevention, and When to Worry

You finish a workout and a headache sets in. It might be dull and achy, or it might be pounding. Either way, it's frustrating—exercise is supposed to make you feel better, not worse.

Exercise headaches are common, usually harmless, and almost always preventable. Here's what you need to know.

Types of Exercise Headaches

Primary Exercise Headaches

These are caused by the exercise itself, not an underlying condition.

Characteristics:

• Triggered by strenuous exercise
• Pulsating or throbbing
• Usually affects both sides of the head
• Lasts 5 minutes to 48 hours
• More common in hot weather or high altitude

Common triggers:

• High-intensity exercise
• Heavy lifting (especially holding breath)
• Running or jumping activities
• Exercise in heat or at altitude

Secondary Exercise Headaches

These are caused by an underlying issue that exercise aggravates or reveals.

More serious causes (rare but important):

• Blood vessel problems
• Structural issues
• Sinus problems
• High blood pressure

Warning signs (see "When to See a Doctor" below)

Most exercise headaches are primary—annoying but not dangerous. However, new or severe exercise headaches should be evaluated.

Common Causes of Post-Workout Headaches

1. Dehydration

The most common cause. When you're dehydrated:

• Blood volume decreases
• Brain tissue can temporarily shrink slightly
• Blood vessels dilate to compensate

Signs it's dehydration:

• Headache worsens as workout continues
• Dark urine
• Thirst
• Dry mouth
• Headache improves with fluids

2. Tension and Muscle Strain

Tight neck and shoulder muscles can refer pain to the head.

Common scenarios:

• Hunching during exercise
• Clenching jaw during exertion
• Poor posture during lifting
• Tight upper traps

Signs it's tension-related:

• Pain feels like pressure or band around head
• Tender spots in neck or shoulders
• Worse after exercises involving upper body
• Often accompanied by neck stiffness

3. Exertion Headache

Intense physical effort can trigger headaches, especially in susceptible individuals.

Common triggers:

• Weightlifting (especially heavy or to failure)
• Sprinting
• High-intensity interval training
• Sexual activity

Signs it's exertion-related:

• Comes on during or immediately after intense effort
• Throbbing quality
• Often at the back of the head
• May last minutes to hours

4. Low Blood Sugar

Your brain needs glucose. When blood sugar drops:

• Brain function is impaired
• Headache often results

Signs it's blood sugar:

• Headache with shakiness
• Occurred after long workout without eating
• Improves with food
• Accompanied by weakness or irritability

5. Caffeine-Related

Both too much and too little caffeine can cause headaches.

Too much caffeine before workout:

• Pre-workout supplements often contain high caffeine
• Combined with exercise intensity, can trigger headaches

Caffeine withdrawal:

• If you normally have caffeine and skip it before morning workout
• Headache is dull and persistent

6. Heat and Sun Exposure

Exercising in heat stresses your body:

• Blood vessels dilate
• Dehydration accelerates
• Body works harder to cool itself

Signs it's heat-related:

• Occurred during hot weather exercise
• Accompanied by flushing, excessive sweating
• May have nausea or dizziness too

7. Blood Pressure Spikes

Heavy lifting and intense exercise spike blood pressure temporarily. In some people, this triggers headaches.

Signs it's blood pressure:

• Occurs during very heavy lifting
• Pounding headache
• May feel pressure in head during lift
• If you have known high blood pressure, more likely

8. Breathing Issues

Holding your breath during exertion (Valsalva maneuver) or hyperventilating can trigger headaches.

Signs it's breathing-related:

• Occurred during heavy lifting
• You were holding breath
• Or breathing very rapidly during cardio

How to Prevent Exercise Headaches

Hydration Strategy

Before:

• 16-20 oz water 2-3 hours before exercise
• 8 oz 20-30 minutes before

During:

• 7-10 oz every 10-20 minutes
• More in hot conditions
• Consider electrolytes for workouts over 60 minutes

After:

• 16-24 oz for every pound lost during exercise
• Continue drinking throughout the day

Nutrition Strategy

Pre-workout:

• Eat 2-3 hours before, or light snack 30-60 minutes before
• Include carbohydrates for energy
• Don't exercise completely fasted if prone to headaches

During long workouts:

• Consume 30-60g carbs per hour after 60 minutes
• Sports drinks, gels, or easily digestible food

Warm-Up Properly

• 5-10 minutes of gradual intensity increase
• Gets blood flowing gradually
• Prepares cardiovascular system for demands

Progress Gradually

• Don't jump to maximum intensity
• Build up over time
• Sudden jumps in intensity trigger headaches

Mind Your Breathing

During lifting:

• Exhale during the effort (concentric phase)
• Inhale during the easier phase (eccentric)
• Don't hold breath for extended periods

During cardio:

• Rhythmic breathing
• Match breath to movement
• Avoid rapid, shallow breathing

Address Tension

If prone to tension headaches:

• Check your form (don't hunch or tense unnecessarily)
• Relax jaw and face during exercise
• Stretch neck and shoulders before and after
• Consider massage or foam rolling for upper traps

Manage Caffeine

• Limit pre-workout caffeine if sensitive
• Stay consistent (don't skip your usual morning coffee then wonder why you have a headache)
• Note whether caffeine makes your headaches better or worse

Exercise Smart in Heat

• Go early morning or evening
• Stay in shade when possible
• Take more breaks
• Reduce intensity
• Hydrate more aggressively

Quick Relief for Exercise Headaches

When a headache strikes:

1. Stop exercising (or reduce intensity significantly)
2. Hydrate with water or electrolyte drink
3. Cool down if overheated
4. Eat something if you haven't recently
5. Stretch neck and shoulders gently
6. Rest in a cool, quiet place
7. OTC pain relief (ibuprofen or acetaminophen) if needed

For exertion headaches specifically:

• Some people find lying down helps
• Ice on back of neck can provide relief
• They usually resolve within hours

When to See a Doctor

Seek Immediate Care If:

• Sudden, severe headache ("worst headache of your life")
• Headache with neck stiffness and fever
• Headache with vision changes, confusion, or weakness
• Loss of consciousness
• Headache after head injury
• Sudden onset during exertion in someone with no history of exercise headaches

Schedule a Doctor Visit If:

• New exercise headaches (especially after age 40)
• Headaches that are increasing in frequency or severity
• Headaches that don't respond to prevention strategies
• Headaches with unusual symptoms (numbness, visual changes)
• You have risk factors for cardiovascular disease
• Headaches that last more than 48 hours

What the Doctor May Do:

• Rule out underlying causes
• May recommend imaging (CT or MRI) for new headaches
• Check blood pressure
• Review medications
• Possibly prescribe preventive treatment for exercise headaches

Exercise Headache Prevention Checklist

Before your next workout:

• [ ] Hydrated throughout the day?
• [ ] Ate appropriately (not fasted, not stuffed)?
• [ ] Managed caffeine intake?
• [ ] Planned a proper warm-up?
• [ ] Appropriate intensity for current fitness?
• [ ] Weather accounted for (heat, sun)?
• [ ] Water bottle ready?

During workout:

• [ ] Breathing properly?
• [ ] Sipping water regularly?
• [ ] Not holding breath during lifts?
• [ ] Posture and form correct?
• [ ] Not overdoing it?

The Bottom Line

Most exercise headaches are caused by:

• Dehydration
• Exertion without proper buildup
• Tension in neck/shoulders
• Low blood sugar
• Heat

Prevention is key: Hydrate, eat, warm up, breathe properly, and progress gradually.

When in doubt, get checked out. New, severe, or unusual headaches deserve medical attention.

Exercise should enhance your life, not give you headaches. With the right prevention strategies, most people can eliminate or dramatically reduce exercise-related headaches.

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Related Articles:

• Why Do I Feel Dizzy After Exercise?
• How to Warm Up Before Exercise
• Hydration and Exercise
• Exercises for Neck Pain