Headaches that occur during or after a swim, often called “swimmer’s headaches,” are common. While generally benign, they can detract from the enjoyment of a swimming routine. These headaches typically fall into three categories: those caused by mechanical pressure, those related to systemic or chemical factors, and those stemming from poor biomechanics. Identifying the specific root cause is the first step toward finding an effective preventative solution.
Preventing Headaches Caused by Pressure Changes
A frequent source of discomfort is the “goggle headache,” medically known as an external compression headache. This pain is caused by overly tight goggles or caps applying continuous pressure to the nerves of the forehead and scalp. The compression of nerves, such as the supraorbital or supratrochlear nerves, results in a steady, non-pulsating pain that feels most intense directly beneath the pressure point.
To avoid this, select goggles that form a watertight seal with minimal strap tension. Position the strap higher on the head, above the ears, to distribute pressure more evenly across the skull. A simple test involves pressing the goggle cups onto the eye sockets without the strap; if they briefly suction and hold, the fit is correct and will not require excessive tightening.
Another pressure-related headache is the cold-stimulus headache, commonly known as “brain freeze,” triggered by rapid temperature changes. Diving into cold water or allowing cold water into the nasal passages causes a swift constriction of blood vessels in the head. This is followed by a rapid rebound dilation, which activates pain receptors and sends a signal through the trigeminal nerve.
Swimmers can mitigate this reaction by gradually acclimating to the water temperature before beginning the workout, such as by splashing water on the face and neck. Using nose clips and earplugs is also beneficial by preventing cold water from entering the nasal and ear canals. This protection helps stabilize the temperature and pressure within the sinus cavities.
Addressing Systemic and Chemical Triggers
The body’s internal state plays a significant role, as even moderate dehydration can induce a headache. When the body lacks sufficient fluid, the volume of blood decreases, which can cause the brain to temporarily shrink and pull away from the meninges—the membrane lining the skull. This pulling sensation, along with electrolyte imbalances, translates directly into a throbbing headache.
Since cool water can mask the feeling of perspiration, swimmers often underestimate their fluid loss, making consistent hydration a challenge. It is prudent to drink water before, during, and immediately after a swim, supplementing with electrolytes if the session is particularly long or intense. Small, frequent sips throughout the workout are more effective than rapidly consuming a large volume at the end.
Headaches can also be a symptom of low blood sugar (hypoglycemia), especially during strenuous or prolonged exercise. The brain relies primarily on glucose for energy, and depletion of these stores can trigger a headache, often accompanied by light-headedness or shakiness. Consuming a light snack rich in complex carbohydrates and protein, such as a banana or crackers, 30 to 60 minutes before swimming ensures a sustained release of energy.
External chemicals, particularly chlorine, can irritate the delicate mucous membranes inside the nose and sinuses, leading to congestion and a sinus headache. The inhalation of chlorine fumes or the entry of chlorinated water into the nasal passages causes inflammation, sometimes called “swimmer’s sinusitis.” To reduce this chemical irritation, swimmers should seek out well-ventilated indoor pools or outdoor facilities. A saline nasal rinse or a neti pot used immediately after swimming can effectively flush residual chlorine and irritants from the nasal cavity.
Optimizing Swimming Form and Gear
Biomechanical stress from poor form is a common cause of tension headaches that radiate from the neck and upper back. During the freestyle stroke, repeatedly lifting the head too high out of the water to breathe puts immense strain on the cervical spine and trapezius muscles. The average human head weighs about 10 to 11 pounds, and constantly lifting this weight against gravity and water resistance leads to muscle tightness.
The correct technique involves rotating the entire trunk of the body, allowing the head to turn only enough to clear the mouth for a breath, keeping the ear aligned with the shoulder. This rotation minimizes the work required by the neck muscles, ensuring the spine remains in a neutral, streamlined position. Consistent practice of bilateral breathing, alternating the side on which you breathe, helps balance muscle development and reduce asymmetrical strain.
Unconscious jaw clenching, known as bruxism, is a less obvious source of headaches often resulting from concentration or physical exertion. The tension created in the temporomandibular joint (TMJ) and surrounding muscles can refer pain to the temples, face, and neck, mimicking a tension headache. Swimmers should practice conscious relaxation, occasionally letting the jaw hang loosely while swimming to release this built-up pressure. Integrating gentle neck stretches and shoulder rolls into a warm-up and cool-down routine helps loosen the muscles that commonly contribute to stiffness and pain.