Pre-workout snacks are a must. After all, you need food to fuel your circuit. But while some on the way to the gym have an iron stomach, others are different. Foods that are fibrous, fatty, sugary, or filling can mess with your digestive tract and send you scrambling for the nearest restroom. Items such as apples, normally a great choice and source of fiber, aren’t what your body needs just before launching into high gear. Ditch these typically harmless foods as pre-workout snacks, and you’ll feel better and train better.

Flaxseeds

A small serving of flaxseeds—under two tablespoons—is a natural laxative and great for regulating your digestive tract. Eating too much, especially without water, may cause loose stools or constipation. That’s not something you need right before a workout or a run. Flaxseeds are a good source of fiber that may help you clear your digestive tract,

Smoothies

Make sure you down your smoothie at least two hours before your workout. Beware of ordering a sugar-filled, unhealthy shake that can spike your blood sugar levels and then crash your energy mid-circuit. Drinking a lot of any liquid increases the need to interrupt your workout for a bathroom break to pee.  That’s not ideal when you’re trying to maintain a higher heart rate consistently. Save the smoothie for a healthy recovery meal post-workout.

Nut Butter/Healthy Fats

Stick to fewer than 15 grams of fat pre-workout or about one tablespoon of nut butter, one ounce of cheese, or two large eggs. Considerably more time is needed to digest fat compared to carbs, and eating too much fat before exercising can make you feel weighed down and leaden. You need high-octane, glycogen-creating fuel for your workout, and that’s not items like avocado and nut butters. Many runners find these items, which normally are great choices, can create acid reflux.

Coffee

Caffeine can help improve your endurance and training intensity, but drink too close to your way out the door and you could be mid-run when you’re hit by a bathroom emergency. The warm liquid helps to activate and move your bowels, and that’s good when you want a quick pre-workout clean-out. Solve the dilemma by giving yourself 20 minutes to process the drink before heading out on your run. Another option for a boost is to choose caffeine tablets or powder which won’t cause the same gastrointestinal distress

Apples

Apples are high in fiber, and that can cause diarrhea or GI distress or during your workouts. Trade off high-residue foods like apples and multi-grain bread for lower-residue alternatives like applesauce or rice cakes before your workout.

Sports Drinks

Sugars like sorbitol, xylitol, isomalt, and mannitol are common in sports drinks, electrolyte tablets, and sports bars. They may cause gas, bloating, cramping, and diarrhea. Unless you’re working out for over an hour or in extreme conditions, you don’t need a specialized sports drink. Water is likely your best bet. And on a long run, choose electrolyte-rich, sugar-free drinks. Read the labels and avoid any added sugars.

Read More: Seemingly Harmless Foods to Stop Eating Before You Work Out