The lower esophageal sphincter (LES) is made entirely of smooth muscle, which means you can’t strengthen it through willpower or direct exercise the way you’d build a bicep. But you can improve its function. The most effective approaches work indirectly: training the diaphragm that wraps around it, removing the foods and habits that weaken it, and reducing the abdominal pressure that forces it open.
Why You Can’t “Exercise” the LES Directly
The LES sits at the bottom of your esophagus, where it meets your stomach. It’s a ring of smooth muscle fibers arranged in clasp and sling patterns. Unlike the skeletal muscles in your arms or legs, smooth muscle operates involuntarily. Your nervous system and local chemical signals control it. You can’t flex it on command, and no repetitive exercise will make it grow thicker or stronger the way resistance training builds skeletal muscle.
What you can do is target the crural diaphragm, a portion of your breathing muscle that wraps around the LES like an external cuff. When the diaphragm contracts during inhalation, it squeezes the area around the LES and helps keep stomach contents where they belong. Strengthening this cuff is the closest thing to a direct workout for reflux control.
Diaphragmatic Breathing Training
Clinical trials have tested specific breathing protocols and found measurable improvements in both LES pressure and reflux symptoms. In one study, patients who practiced abdominal breathing for 30 minutes a day over four weeks had significant symptom improvement. Another trial used a more intensive schedule of five sessions per day, five days a week, for eight weeks. A European Respiratory Society study measured the results precisely: inspiratory muscle training raised baseline LES pressure from about 19 mmHg to nearly 23 mmHg, while heartburn frequency dropped from two to four episodes per week to less than one.
The technique itself is straightforward. The goal is to shift your breathing pattern from your chest to your abdomen. Sit or lie down, place one hand on your chest and one on your belly, and breathe so that only your belly rises. Your chest should stay relatively still. For the diaphragm to engage fully, your rib cage needs to stay in a relaxed, slightly lowered position rather than flared upward. Based on the protocols that showed results, aim for at least 30 minutes of practice daily for a minimum of four weeks.
Foods and Drinks That Weaken the LES
Certain foods chemically relax the LES, lowering its resting pressure and making reflux more likely. The main culprits are high-fat meals, chocolate, carbonated beverages, and alcohol. Fatty foods are particularly well-documented: they trigger the release of signals that cause the sphincter to relax more frequently, independent of swallowing. This creates openings for stomach acid to move upward.
The American College of Gastroenterology recommends avoiding personal trigger foods for symptom control. The evidence is strongest for cutting back on carbonated drinks and fatty meals. For citrus and spicy foods, the recommendation is more individual: avoid them if they trigger your symptoms, but they don’t universally lower LES pressure in everyone. Caffeine’s effect on the LES is equivocal in studies, so switching to decaf isn’t broadly recommended unless you notice a personal connection.
Eating smaller meals also helps. A large meal distends your stomach, raising internal pressure above what the LES can resist. Eating less at each sitting reduces that pressure differential. The ACG also suggests finishing your last meal at least two to three hours before lying down, giving your stomach time to partially empty before gravity stops working in your favor.
Why Weight Loss Matters
Excess abdominal fat physically compresses the stomach, raising the pressure inside it. When that pressure exceeds what the LES can hold, reflux happens regardless of how well the sphincter is functioning. Visceral fat (the type packed around your organs, not just under the skin) is the bigger problem, and it’s also associated with a higher rate of hiatal hernia, a condition where part of the stomach slides above the diaphragm and further undermines LES function.
Weight loss is the only lifestyle change that the ACG rates with “strong” recommendation strength for GERD improvement. Even modest reductions in abdominal circumference can lower the mechanical load on the sphincter.
Sleep Position and Timing
Sleeping on your left side keeps your esophagus positioned above the gastroesophageal junction. When you lie on your right side, the anatomy flips: the junction sits above the esophagus, and acid pools where it can easily flow upward. A systematic review confirmed that left-side sleeping is associated with fewer reflux episodes and shorter acid exposure time.
Elevating the head of your bed by about six inches (using a wedge or bed risers, not just extra pillows) also helps gravity keep acid in the stomach during the night. This is especially useful if nighttime symptoms are your main problem.
Medications That Can Weaken the LES
Several common prescription drugs relax the LES as a side effect. These include certain blood pressure medications (calcium channel blockers), some asthma drugs, sedatives like benzodiazepines, and anticholinergic medications used for bladder control or allergies. Long-term daily use of these drugs for more than five years has been linked to a nearly fourfold increase in risk of a specific type of esophageal cancer, likely because the chronic reflux they promote damages the esophageal lining over time.
If you’re taking any of these and experiencing reflux, it’s worth discussing alternatives with your prescriber. The LES-weakening effect is dose-dependent and cumulative, so even reducing the dose or switching to a different class can help.
Melatonin and LES Pressure
Melatonin, commonly known as a sleep supplement, has shown an unexpected effect on LES function in clinical research. In one trial, patients who took 3 mg of melatonin daily for eight weeks saw their LES pressure rise from about 10 mmHg to 16.5 mmHg, a roughly 65% increase. The gut produces far more melatonin than the brain does, and it appears to influence smooth muscle tone in the esophagus and stomach.
This is still a relatively small body of evidence compared to the breathing and lifestyle data, but the effect size is notable. Melatonin is inexpensive and widely available, with a well-established safety profile at the 3 mg dose.
Surgical Options for Severe Cases
When lifestyle changes and medications aren’t enough, a device called LINX offers a mechanical solution. It’s a small ring of magnetic titanium beads placed around the junction between the esophagus and stomach during a minimally invasive procedure. At rest, the magnets hold the ring closed with about 40 grams of force, enough to prevent acid from creeping upward. When you swallow, the force of the food bolus pushes the beads apart (they resist with only about 7 grams when fully separated), allowing normal passage.
In a systematic review covering over 1,500 patients, 75% to 100% were able to stop taking acid-suppressing medications after surgery, depending on the study. The most common side effect is difficulty swallowing, which occurred in a wide range of patients but typically resolved over time. About 8% needed a balloon dilation procedure to stretch the area, and 2% ultimately had the device removed. Erosion into the esophageal wall is rare, occurring in roughly 0.03% of cases.
Putting It All Together
The most practical daily plan combines several of these strategies. Practice diaphragmatic breathing for 30 minutes a day. Eat smaller, lower-fat meals and stop eating two to three hours before bed. Sleep on your left side with the head of your bed elevated. If you’re carrying extra abdominal weight, prioritize losing it. Review your medication list for drugs that may be relaxing the sphincter. Consider trying 3 mg of melatonin at bedtime. These approaches work through different mechanisms, so stacking them produces a larger cumulative effect than any single change alone.