Skip These 5 Foods If You’re Working Out Soon

Elizabeth Millard
by Elizabeth Millard
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Skip These 5 Foods If You’re Working Out Soon

We’ve all been there: You’re just gearing up to crush a workout, and then it strikes. “It” being the stomach cramping, the bathroom urgency, the wave of fatigue. If you’re exercising outside or in the middle of a fitness class, this gastrointestinal distress can be even more discouraging.

Although a sudden virus might be at play, it’s more likely that what you ate just before working out could be the culprit. “Exercise and digestion are mutually exclusive,” says Shawn Khodadadian, MD, of Manhattan Gastroenterology. “When you exercise, your body isn’t using its energy for digestion. It slows that process so it can divert as much blood as possible to your muscles and lungs.”

That means foods you digest just fine when not working out could cause you problems if you eat them pre-exercise. Certain foods can prompt heartburn, stomach ache or even vomiting, Khodadadian notes.

Here are some common food choices to avoid:


While protein is very helpful for post-workout recovery, it can be tough on your system if you have a shake right before working out. That’s because protein digests slowly, Khodadadian says. If you’re having a shake less than three hours before a workout, you could see some digestive blowback. The same goes for a high-protein bar.

The fix: If you regularly rely on a protein boost right before working out, and tend to feel not-so-great while exercising, try having the shake or bar after exercising instead.



Many runners love their chocolate milk fix, but they’re careful to drink the beverage after a big run or a race. That’s because milk has high amounts of protein and fat, which take time to digest.

The fix: If you’re looking for a dairy-type boost in your pre-workout mix, consider whey protein mixed with filtered water instead — but even then, consume the drink at least a few hours before your workout.


Loading up on a carb-rich choice like cereal is tempting before exercising, especially if you’re pressed for time. But, like protein, fiber digests slowly, and your workout can interfere with that process, Khodadadian notes.

The fix: As an alternative, try a food you can digest easily that’s high in carbs but low in fiber, such as oatmeal. That way, you can get the fuel you need without the GI issues. Consider adding even more of a carb boost with bananas or mangoes.



Even if you regularly amp up your spice levels, you may have issues if you eat too much before working out. The slower digestive processes that happen when you begin exercising could leave that delicious taco sitting in your stomach, and that can prompt indigestion or heartburn.

The fix: Skip the spice altogether and save the heat for a post-workout treat.


Yes, you should load up on vegetables. But eating raw veggies can be tricky, says Terry Wahls, MD, author of “The Wahls Protocol.” Although raw vegetables have more fiber than cooked, they also have intact enzymes and their cell walls are still solid, which means it takes more energy for your body to digest them. If you’re just sitting in an afternoon meeting, that’s no big deal. But if you’re trying out your new HIIT workout, it can become a source of digestive problems.

The fix: Opt for easier-to-digest, lower-fiber cooked vegetables and save the salad for another time.


Although some people swear by “fasted cardio” workouts, it’s usually more effective to eat something before exercising, according to Khodadadian. He says, “Not eating anything before a workout will leave you feeling tired and weak. Just give your body the proper time to digest before exercising, you may need two or three hours for digestion.”

Your blood sugar rises to help you digest, he adds. By waiting a few hours, those blood sugar levels will drop back to normal, giving you the energy you need to devote to your workout — without a stomach ache or heartburn along the way.

About the Author

Elizabeth Millard
Elizabeth Millard

Elizabeth is a freelance journalist specializing in health and fitness, as well as an ACE certified personal trainer and Yoga Alliance registered yoga teacher. Her work has appeared in SELF, Runner’s World, Women’s Health and CNN.


31 responses to “Skip These 5 Foods If You’re Working Out Soon”

  1. Avatar G Thomson says:

    Right, I’m TOTALLY confused by “1. PROTEIN SHAKES & BARS”, really? My understanding is that if you work out early in the morning (I do – 7.00am) then all the protein you had has been digested and a small amount of Whey protein (around 20g) is needed. So what gives? Is it no protein at all?

    • Avatar Mel says:

      To my knowledge protein is to help RESTORE your muscles and it can be hard to digest at times. That’s why she was saying have protein after. It is very important to have but just not right before a workout. Hope this helps! 🙂

      • Avatar dlferriola says:

        I take a protein shake that is made to take before you workout and have never had a problem. The one I have been taking is by Melaleuca either Access or 20/20 shake

        • Avatar bryan wilbourn says:

          My guess is, the article is meant to be taken as advice for a broad spectrum of people regardless if they can handle having protein before a workout or not. Humans are all different. So this article could be targeted for a specific audience that has trouble with their digestive system during a workout. By making it one size fits all the author hurt her cause but then again, just b/c you aren’t having issues with something now doesn’t mean it’ll always be that way.

  2. Avatar Brian says:

    I find box cereals to generally be high in carbs and LOW in fiber while oatmeal is high in both carbs AND fiber

  3. Avatar Zoe Caitlin Bevers says:

    I agree with the comment about how, though some enjoy fasted cardio, it’s usually (for me, always) more effective to eat first. For me as a diabetic who can feel my hypoglycemia moments, failure to do so is actually self-harm.

  4. Avatar Loren Wilkins Bethea says:

    I work out at 6:15 am. If your food needs several hours to digest, that puts me getting up at 4:am to eat and that’s not going to happen! What would you suggest I eat at 5:30 am for a very intense 6:15 am workout? I usually eat 1/2 a banana. Thanks!

    • Avatar Lina says:

      I workout better on an empty stomach. I just take some pre workout supplement (No Xplode) and I have a high protein meal after.

    • Avatar Orion Antares says:

      For me, I’ve done well just using some BCAAs, choline, and caffeine for “fasted” training sessions.

    • Avatar Mathieu Langevin says:

      May i suggest an apple pre-workout instead of banana since it will help boost your testosterone for a better workout and the banana should be post workout due to its anabolic nature (carbs) right before you get those proteins in 🙂

  5. Avatar Bill Laughner says:

    Where’s the science to back these claims? I love when people post their claims without the research to back it up.

    Please don’t listen to this. Having a pre-workout Shake with a good pre-workout supplement and an apple for carbs about 40min before a workout is not going to hurt you !! Don’t need 2-3 hours to digest.

  6. Avatar StealthM93 says:

    FWIW, as I age (46 now), having a 2 to 3 hours of non-eating does lead to a better workout (both strength/tone conditioning and cardio). Of course, it really helps the that prior meal is a healthy one. 🙂

  7. Avatar Carol Lynn Thistle says:

    I made it to the crossfit games in 2017 as a 60+ Master Woman. I started working with a nutritionist 6 weeks before I left. She did not feel I could get the best out of my workout at 5:30 am. after not having eaten for several hours since dinner. So I started getting up at 4:20 and I drink UCAN, a carb powder with water, eat half a banana and eat a piece of Eizekiel Toast. I drink a scoop or two of protein with just water after my workout and before I eat breakfast. I was 11.5% body fat and went to 8.5 in short order. I lost a few pounds of weight from 118 to 115 but I”m working on bringing that back up and I gained muscle mass. This is a case in point — your body needs something to fuel it for the workout and the protein should be taken after and then eating with proper foods like chicken, fish and shrimp throughout the day. I feel so strong, my endurance is great and my weightlifting is stronger. I hope this helps someone….

  8. Avatar Bcorig says:

    King sized Snickers bar and 20 ounces of Diet Coke 45 minutes before.

  9. Avatar TastyWheat says:

    I always eat way before working out, at least 3+ hours, i get cramps and am very sluggish if i eat first….i usually wait until after. Especially if i am running, i always run on an empty stomach, i run so much faster.

  10. Avatar Maria says:

    I feel very tired and its very hard to run on a full stomach. I love this article because everything in it is truly real. Even when I eat a salad its very hard to get a good workout. Thank you so much for this article.

  11. Avatar Noey says:

    Hmm… Protein shakes “tough on your system”?? I was under the impression that these shakes were already pre-digested, so your body does not have to work nearly as hard to digest them.. I enjoy a shake in the morning, about a half hour to an hour before I get to the gym, and I feel just fine throughout my workouts.. But anyhow I would love some clarity on this topic… Are these shakes in fact hard on our systems or easily digested?

  12. Avatar Fawn B Morgan says:

    I think these claims are focused on, and perhaps limited to, those who experience digestive distress when exercising.

  13. Avatar Sam says:

    “Your blood sugar rises to help you digest” is technically incorrect… if that was the case, type 1 diabetics would have the best digestion out there, due to blood sugar rises. Your body will release the hormone insulin to break down the carbs and help you absorb them, but this has nothing to do with digestion!
    Article could have been written in 2 sentences: Don’t eat foods that are hard to digest – i.e. high in protein, fat or fibre – in the hour before your workout. Eat simple carbs for an energy boost, and proteins for repair afterwards.

  14. Avatar Cassandra Patrick says:

    I tried eating before my 5 am workout and all that happened was I wanted to be sick. So I have coffee and then a protein shake afterwards. Breakfast is two hours after that.

  15. Avatar Gra Xx says:

    Hey you it ok to do my morning ego workout at 5.09 am instead of 5.06?

  16. Avatar Gra Xx says:

    yeah,what I do is have one of my sucker pills,at 29.95 a bottle,then half a banana pointed in a southerly direction,then one lentil bean. Them I’m right to go.

  17. Avatar Joan M says:

    This is silly. For the average non-professional-athlete person trying to get/stay in shape, the most important thing is JUST DO IT…and not get all bent out of shape about nutrition timing. This might be useful for someone who has digestive distress during workouts, but otherwise, just do your doggone workout and eat healthy

  18. Avatar Andrea says:

    This notion that your body can’t exercise and digest food at the same time is what fueled the belief that you shouldn’t swim after eating — a myth that has been disproved long ago! Most people do not, in fact, experience any sort of gastro-intestinal upset if they work out after consuming healthy foods to which their bodies are accustomed. A few people with sensitive digestive systems might experience issues if they eat “special” foods that they wouldn’t normally consume just because they think they need a “pre-workout snack” (another fitness myth that needs to be dispelled.)

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