Quick Answer
Maurten gels cause stomach pain for some runners because of their unique hydrogel technology that relies on a high concentration of fructose and glucose (2:1 ratio). For a subset of athletes, fructose malabsorption or rapid gastric emptying triggers bloating, nausea, and a “baseball in the stomach” sensation. The fix is not to quit fueling – it’s to train your gut, adjust your gel timing, or switch to a different fuel source.
Why This Happens
Maurten gels are designed to bypass the stomach by forming a hydrogel in the acidic environment, allowing carbohydrates to pass directly into the small intestine. This reduces the risk of gastric distress in many runners. However, the gel still contains high fructose load (about 30g per gel). Fructose absorption requires specific transporters in the small intestine. If you lack those transporters (common in up to 30% of the population), the unabsorbed fructose pulls water into the gut, causing cramps, bloating, and diarrhea. Additionally, the hydrogel can sometimes irritate the stomach lining if consumed too quickly or without enough water. The “baseball” feeling is often a result of gas distension or delayed gastric emptying due to the gel’s osmotic effect.
Step-by-Step Method
- Start gut training: Practice fueling on every long run, starting 4-6 weeks before your goal race. Use the same brand and timing you plan to use.
- Hydrate properly: Drink water with each gel (not sports drink) to dilute the osmotic load. Aim for 4-6 oz per gel.
- Time your gels: Take a gel 15 minutes before a planned water stop, not when you’re already dehydrated or overheated.
- Lower the dose: Instead of taking a full gel every 30 minutes, try half a gel every 15-20 minutes. This reduces the sugar hit per interval.
- Alternate sources: Mix Maurten with another fuel like a lower-fructose gel (e.g., GU Roctane, Hüma) or a sports drink with a lower sugar concentration.
- Test on empty stomach: Do a fasted run with a single gel to isolate the reaction, then gradually add more.
Common Mistakes
- Taking gels without water: Gels are hypertonic and draw water into the gut if not diluted. Always drink water alongside.
- Using expired or heat-damaged gels: Gels that have been stored in a hot car can break down and become harder to digest.
- Sticking to one brand exclusively: Even if Maurten works for some, your gut may need a different ratio of glucose to fructose (e.g., 1:1 instead of 2:1).
- Ignoring personal tolerance: Just because a pro uses it doesn’t mean it’s right for you. Test before race day.
- Fuelling too late: Waiting until you feel hungry or bonking leads to rapid consumption that shocks the stomach.
Checklist or Decision Table
| Fuel Type | Carb Source | Fructose Content | Risk of GI Issues | Best For |
|---|---|---|---|---|
| Maurten Gel | Maltodextrin + Fructose (2:1) | ~15g per 60g gel | Moderate for non-adapted | High intensity, long runs |
| GU Roctane | Maltodextrin + Fructose (~1:0.8) | ~10g per 30g gel | Low | Endurance, sensitive stomachs |
| Hüma Gel | Brown rice syrup (glucose polymers) | None (pure glucose) | Very low | Sensitive stomachs, slower absorption |
| Clif Shot Bloks | Maltodextrin + fructose blend | ~5g per block | Low-Medium | Easy to chew, adjustable dosage |
| Whole food: dates | Natural sugars (glucose+fructose) | ~3g per date | Low | Low and slow fueling, training runs |
When This Advice Does Not Apply
If you have diagnosed fructose malabsorption, severe IBS, or a history of gastroparesis, the above methods may still cause issues. In that case, consult a sports dietitian or gastroenterologist. Also, if you are running in extreme heat or humidity, gut blood flow decreases, making any gel harder to absorb – switch to liquid fuel only. This advice is for training, not race day without prior practice.
Realistic Example
Tom, 34, was training for a spring marathon. During his 18-miler, he used Maurten gels every 30 minutes as instructed on the package. By mile 12, he felt a heavy lump in his stomach, belched repeatedly, and nearly vomited at mile 15. He walked home. For his next long run, he halved the dose: half a gel every 20 minutes with extra water. He also added a small bag of crackers for variety. He completed 20 miles without stomach pain. On race day, he stuck to his new protocol and finished without GI distress.
Final Takeaway
Maurten gels are effective but not universal. If you experience stomach pain, lower the dose, increase water intake, and consider a different carb ratio. Train your gut as you train your legs – slowly and consistently. The goal is not to avoid fueling but to find the fuel that works for you.
FAQs
Can I mix Maurten gels with sports drinks?
No, you should not mix Maurten gels with sports drinks that contain additional sugars or electrolytes. The extra sugar can increase the osmotic load and worsen stomach upset. Stick to water only when taking a gel. If you need electrolytes, take them separately, e.g., with a salt tablet 15 minutes after the gel.
How long does gut adaptation take?
Most runners need 4 to 6 weeks of consistent fueling on long runs to adapt their gut. Start with small amounts (half a gel) and gradually increase the dose and frequency. If you are still having trouble after 8 weeks, consider a different fuel source. Adaptation doesn’t happen overnight.
Is there a difference between solid food and gels for stomach issues?
Yes, solid food like dates, bananas, or energy bars requires more chewing and stomach processing, which can reduce the osmotic shock of concentrated sugars. However, they are harder to digest during high-intensity efforts. Gels are faster but more concentrated. For sensitive stomachs, a combination of low-fiber solid food and diluted sports drink may work better than gels alone.
Can I take antacids before a run to prevent stomach pain?
Antacids are not recommended for preventing stomach pain from gels. They reduce stomach acid, which can actually slow down digestion and alter the gel’s hydrogel formation. The pain is usually from fructose malabsorption or gas, not acid. Instead, address the fuel itself. If you have chronic acid reflux, consult a doctor.
Should I avoid Maurten if I have IBS?
If you have irritable bowel syndrome (IBS), especially with fructose intolerance, Maurten gels may trigger symptoms. Start with a single half-gel during a short run to test. Alternatively, try a fructose-free gel like Hüma or pure maltodextrin-based products. Always test on training runs, not race day.
What should I eat the night before a long run to avoid stomach issues?
Eat a low-fiber, moderate-carb meal the night before, such as white rice with chicken or pasta with simple sauce. Avoid high-fiber vegetables, beans, or heavy fats. Hydrate well but not excessively. On race morning, eat a light breakfast 2–3 hours before, such as a bagel with peanut butter or a banana, and skip the large coffee.