Skip navigation

Active Expert: Nancy Clark RD CSSD

9 Posts tagged with the pre-exercise_food tag

Q. Help! What’s the solution to intestinal problems during long runs?


A. Upset stomachs, nausea, cramping, and urgency to take a pit stop are common problems among long distance runners. Because each person has his or her personal response to long runs, I can only ask you lots of questions, but perhaps they will help you find an answer. Here goes...


• Are you running too far, too fast too soon and your body is telling you it isn’t ready for that distance?

• Are you stressed and anxious on long-run days, and your nerves are creating the problem?

• Do you eat too much food the night before? If so, try having your big meal at brunch the day before and eat lighter at night.

• Do you eat too much breakfast before the long run? Try eating part of the breakfast the night before, at bedtime, so you’ll be less hungry in the morning.

• Do you eat fatty, heavy foods (like a sausage, egg ‘n cheese biscuit) before the long run?

• Do you drink too much pre-run coffee?

• What do you use for fuel during the long runs? Gels sometimes cause GI problems. So can commercial sports drinks or candies with the wrong kind of sugar for your gut.

• Are you chewing sugarless gum? The sweetener (sorbitol) can cause GI distress such as gas and diarrhea.

• Do you eat yogurt, kefir, or take probiotics? They can help resolve bowel issues.

• Do you get dehydrated? Lack of fluids contributes to diarrhea.

• Do you eat a high fiber diet? “Healthy” diets with abundant whole grains, fruits and veggies can become problematic for some runners.

• Is the problem limited to during runs or do you have intestinal issues at other times of the day? Perhaps you have latent Irritable Bowel Syndrome that gets aggravated during long runs?

• Do other people in your family have intestinal issues, like constipation, diarrhea, bloating, or colon cancer? Perhaps you have problems digesting gluten (a genetic tendency) and should be tested to see if you have Celiac Disease?

• Have you kept food logs to track potential culprits so you can pinpoint, or at least narrow down, the problem?


Good luck being a food detective! And don’t hesitate to seek medical advice if all of the above suggestions fail to find a solution. A consultation with a local sports dietitian for a nutrition check-up can be very helpful! See for a referral network.


Please add your comments if you have found a solution not mentioned above!

4,584 Views 0 Comments Permalink Tags: running, nancy_clark, pre-exercise_food, diarrhea, constipation, runner's_trots, intestinal_problems_in_runners

Here is Part II of this Marathon Prep series, written by guest blogger Sarah Gold.

What to eat before a long run can be a stressful decision. You need to figure out what foods will provide adequate fuel without upsetting your stomach or the rest of your gastrointestinal tract. As you read last week, training your gut to tolerate food is important, but knowing what foods to choose and which ones to avoid can improve the performance and enjoyment of your training runs. Remember to practice your race-day breakfast on your long training runs leading up to the big day!


What should I eat?

Before a long run, your meal should include carbohydrates that digest easily and are low in fiber. Aim for approximately 2 calories of carbohydrates per pound of body weight (0.5g carbs per lb). A 150lb runner would want approximately 300 calories in carbohydrates. This will add to your glycogen stores and play a role in keeping your blood sugar constant. It will also keep hunger down during your run.


Don’t go crazy counting carbohydrate grams; this is just a guide. Adding a little fat or protein can help with satiety and flavor, but the carbohydrates are the most important factor here. Also, too much protein or fat can sit in the stomach, making for an unpleasant run. Some good pre-run choices include:

o     Toast (or a bagel) with jam & a medium banana

o     Cereal with milk and a banana

o     Oatmeal with berries or raisins

o     Pancakes (1-2) with fruit

o     Granola bar that is low in fiber

o     Fruit smoothie: 1 large banana, ½ cup berries, ½ cuplow-fat milk (or yogurt for extra creaminess), ice cubes.

o     Trail mix with dried fruit, cereal, and pretzels

o     Crackers with hummus and fruit


When should I eat?

While you want to allow 1 to 2 hours after a substantial pre-run breakfast to allow enough time for digestion and absorption, you can likely tolerate a smaller (200 to 300 calorie) snack within an hour pre-run. If you don’t have any trouble with running with food in your stomach, you can shorten this window. However some runners with digestive concerns get up early, eat breakfast, and then go back to bed. Others eat an extra snack before they go to bed, and then eat something smaller in the morning only 30 minutes before a run.


What if I get an upset stomach or GI tract when I eat before a run?

By starting with small amounts of food, most runners can train their GI tract to accept some food. Even a little fuel can improve energy and performance. Some people like sports drinks because they may feel less heavy in the stomach.  If you really struggle, try to eat your breakfast the night before. Before you go to bed, enjoy a carbohydrate-rich snack, such as a bowl of cereal or a bagel . However, I would not recommend running the full marathon without eating the morning of the race, so it’s best to try to train your gut to tolerate food.


Eat wisely and run well!
Nancy and Sarah


For more information:

Food Guide for Marathoners

Food Guide for New Runners

2,705 Views 0 Comments Permalink Tags: boston_marathon, nancy_clark, pre-exercise_food, what_to_eat_before_runs

Nancy, is it better to exercise fed or fasted? I exercise for fitness and weight reduction at 6:00 a.m.. (I do cardio at the gym for an hour.) When I train fasted, I lack energy -- but I’ve heard training fasted helps burn more fat and I want to be lean. I feel so confused…


Answer: As long as you can tolerate a pre-exercise snack, you should enjoy about 100 to 300 calories (as tolerated). You can even eat this fuel just a few minutes before you workout (no need to get up earlier)!


Your body can digest the food and use it to energize your exercise as long as you are exercising at a pace that you can maintain for more than 30 minutes. So, if you grab a banana as you head to the gym, you likely will have a far more enjoyable workout, be able to work harder, and be less hungry at the end of the exercise session. If you do not eat a snack, and if you did not have a hefty evening meal and/pr snack the night prior, you may become light-headed, dizzy, and wishing you were not exercising.


The food you eat at breakfast might deter “fat burning,” but that is irrelevant in terms of body fatness. That is, sleep is a fat-burning activity, as is watching TV. The issue is not "are you burning body fat" but "have your created a calorie deficit before bedtime." You need to be in calorie deficit by the time you go to bed in order to lose undesired body fat that day. This has little to do with burning fat during your morning workout.


I suggest the best time to diet (eat less) is at the end of the day, not during the active part of your day. If you “fuel by day and diet by night”, you’ll enjoy your workouts, be able to exercise harder (and burn more calories), curb your evening appetite, be able to eat a lighter dinner, and be more successful as an athlete and a dieter.


Enjoy that banana, granola bar, English muffin, or whatever is easy to grab-and-go! If early morning food fails to settle well, then have some sports drink during your workout if you start to feel draggy.


Fuel wisely and feel great!



PS. For more information, please refer to my Sports Nutrition Guidebook (www.nancyclarkrd/com)

1,687 Views 0 Comments Permalink Tags: nancy_clark, pre-exercise_food, fat-burning, morning-exercise, what_to_eat_before_exercise

Nancy. I'm training for the Las Vegas 1/2 Marathon in December, which starts at 5:00 pm. I've never run an evening race before and have no idea how to eat that day. I'd love information about how to fuel for an evening race -- breakfast, lunch, pre- and post-race nutrition.

Thanks! Kimberly



Because each runner has differing abilities to tolerate foods and fluids before, during and after a running event of any distance, offering one-size-fits-all sports nutrition advice is difficult. That’s why you want to figure out DURING YOUR LONG TRAINING RUNS what eating pattern will work best for your body.

     I highly recommend you plan to do several long training runs at the same time as the race, 5:00 p.m. That will give you the opportunity to practice your fueling strategies. Those training runs, however, will not evoke the same gut-troubling level of stress and anxiety that you may have on the day of the event…hence, your first evening half-marathon will really be your “practice” one.


• The week before the half-marathon, you will want to:

--taper your training, so your muscles have time to heal and get fully fueled with carbohydrates.

--enjoy carb-based meals to provide the fuel needed to carbo-load your muscles. {Protein builds and heals muscles, but fruits, vegetables, and grains are best to fuel your muscles.)

--drink plenty of fluids, so you enter into the event well hydrated.


• On the day of an 5:00 p.m. event, if you are afraid you might be too nervous to eat close to race-time, plan to enjoy a hearty carbohydrate-based brunch (pancakes, French toast, or tried-and-true cereal-banana-bagels-fruit) at 10:00 or 11:00 a.m. and then a 3:00 pm, have a lighter snack (energy bar, banana, pretzels, bagel, sports drink) or what ever seems like it would settle well and digest easily.


• If you are less fearful of intestinal problems, enjoy your standard breakfast, a hefty carb-based meal such as pasta at noon, and then a bagel (with peanut butter) or turkey sandwich at 3:30-4:00ish, to curb pre-event hunger.


• If you will be running more than 90 minutes, you will want to fuel during the half-marathon, targeting about 150-250 calories per hour, starting after the first hour (or sooner, if you have been unable to eat for several hours pre-event.) How many calories you need will depend on your body size (bigger runners need more fuel). Drink enough sports drink or water+sports foods to quench your thirst, but stop drinking if your stomach is “sloshing.”


• After the half-marathon, enjoy a nice recovery meal that suits your cravings. Preferably, it should be carb-based, to refuel your muscles, with a side of protein to repair your muscles. Some people like burgers or steak, as a change from carbs. If that’s your case, just be sure to enjoy some potato, rolls, veggies and other carb-based foods alongside the protein.

     Because you will unlikely be running again the next day, you need not fret about recovery; your muscles will have plenty of time to refuel before your next training session. But a proper carb-based diet with a side of protein plus extra fluids will optimize recovery so you feel great sooner than later.


Have fun!



For more detailed information, please refer to my Food Guide for Marathoners: Tips for Everyday Champions (

1,300 Views 0 Comments Permalink Tags: half-marathon, carbohydrates, nancy_clark, pre-exercise_food, food_guide_for_marathoners, carb-loading, fueling_for_evening_event, recovery_food, feuling_during_long_run

Dear Nancy,


We currently have 9 dogs that we train and compete with in herding competitions. We train on a daily basis, locally as well as nationally. ( is our kennel website.)


I can tell you for sure that a hungry dog isn’t at his best. Hungry dogs are quicker to get in a fight, but they may not necessarily win. When we compete with our dogs, not only do we need physical strength but also we need mental sharpness. (The dog has to obey some pretty complex commands when taking the livestock through the course.) A dog that is hungry (or hasn’t eaten the morning of a competition) tends to get tired when things get tough (i.e., he won’t work as hard to turn back a running cow.)


They also get mentally sloppy as the day wears on. They will forget what ‘right’ and ‘left’ means sometimes. Or they will get sloppy and allow one sheep to split from the group and they won’t bother putting it back. All this sloppiness results in losing points during your run.


Since our dogs can’t talk to us, we have to observe their behavior and adjust their nutrition based on the results we see. I can tell you for sure, that a dog that has had several small meals (or snacks) throughout the day lasts longer, tries harder and is mentally sharper than a dog that skipped breakfast and has only had water to drink. I think dogs are pretty much like humans.


I’m thinking any coach that gave that advice never trained dogs!


Allison Bryant

615 Views 0 Comments Permalink Tags: hunger, pre-exercise_food, hungry_dogs

Have you have ever wondered which is the best energy bar? The answer is the best choice is the product that pleases your taste buds and settles well in your stomach. You simply need to experiment to determine which products (if any) work best for your body.


A multitude of businesses have jumped on the bandwagon to create sports foods that appeal to a variety of athletes, including those with special diets (such as gluten-free or vegan) and athletes who are just plain hungry and want a “healthier” cookie (most energy bars!).


While busy athletes enjoy the ease of using pre-wrapped sports foods, these commercial products tend to be more about convenience than necessity. Certainly, there is a time and place for these products, but “real” food can do the same job at a lower price. Please don’t underestimate the power of peanut butter, bananas, and honey!


Below is an extensive (but incomplete) list of various types of energy bars. Perhaps the information will help you untangle the jungle of choices.


ENERGY BARS (for extra energy, not a meal replacement):

All natural/organic ((have no added vitamins or minerals):

Clif Nectar, Clif Mojo, Lara Bar, Optimum, Honey Bar, Odwalla Bar, PowerBar Nut Naturals, KIND Bars, Zing Bars, NRG-Bar, Honey Stinger Bars, Kashi Bars, Peak Energy, Perfect 10, Gnu Bar, Raw Revolution Bar, Olympic Granola Bar, Pure Bar, Pro bar, Sun Valley Bar, Bonk Breaker Energy Bar


Caffeine-containing bar: Peak Energy Plus


Dairy-free: Clif Nectar, Clif Builder's, Olympic Granola, Pure, Bonk Breaker Energy Bar, Gnu Bar, Fit, Perfect 10, Larabar, AllerEnergy Bar, Soy Rocks Bar


Grocery store options: Nature Valley Granola Bar, Nutri-Grain Bar, Quaker Chewy Bars,  Fig Newtons


Fructose-free:  JayBar


Gluten-free: Perfect 10, Hammer Bar, EnvirKids Rice Cereal Bar; Omega Smart Bars, Extend Bar Delight, Zing Bar, BoraBora Bar, Wings of Nature Bar, Elev8Me. Wheat-free but may not be gluten free (due to cross-contamination with wheat products in the manufacturing plant): Larabar, Odwalla Bar, Clif Nectar, Clif Builder, Bonk Breaker


Kosher: Pure Fit, Larabar, Extend Bar, Balance Bar, HoneyBar


Meal replacement bar (with 10-15 g protein): Kashi Go Lean Bar, MetRx Mr. Big, MetRx Big 100 Colossal, Balance Satisfaction


Nut-free: AllerEnergy Bars, Metaballs


Peanut-free: Soy Rocks, AllerEnergy bar, Larabar


Protein bars (soy, whey, egg, or blended protein source):

PowerBar ProteinPlus, EAS Myoplex Delux, High 5 Protein Bar, Maximuscle Promax Meal, Tri-O-Plex, Clif Builder's Bar, Detour Bar, Honey Stinger Protein Bar, Pure Protein


Raw food: Raw Revolution, Pure Bar


Recovery bar (4:1 carb:pro ratio): PowerBar Performance


Soy-free: Larabar, Perfect 10, Clif Nectar, KIND Bar, Bumble, Gnu Bar, Raw Bar, Zing

Bar, NRG-Bar, AllerEnergy Bar


Vegan: Pure Fit Bar, Larabar, Hammer Bar, Clif Builder's Bar, Pro Bar, Vega Whole Food Raw Energy Bar, Perfect 10, Soy Rocks Bar


Vitamin+protein-filled candy bar: Marathon Bar, Detour Bar


Women's bars (fewer calories; soy, calcium, iron, folic acid):

PowerBar Pria, Amino Vital Fit, Luna Bar, Balance Oasis   


40-30-30 Bars: Balance Bar, ZonePerfect

1,200 Views 0 Comments Permalink Tags: pre-exercise_food, energy_bars, commerial_sports_foods

Yes! Despite popular belief, eating a fruit- or grain-based snack, such as an energy bar, banana, handful of pretzels, or an apple, just 5 minutes before a workout can boost your energy at the end of the session. Research also suggests that eating 15 minutes before you exercise is as effective for boosting your energy as eating an hour before.

Your body can digest food while you exercise. Your muscles get to use the food to enhance your workout, as long as you are exercising at a pace that you can maintain for more than half an hour. Most athletes train at a moderate pace, hence they can benefit from a pre-exercise energy booster. If you’ll be doing a sprint workout, you might want to eat an hour or two pre-exercise, so the food has time to empty from your stomach.

Your best bet is to experiment with different pre-exercise snacks, to determine when you can eat them without causing distress, and which ones settle best and help you perform at your best.


Having a drink of water right before exercise is also a smart idea, even if you will be exercising for less than an hour. Water is also helpful during exercise. Water can turn into sweat In only 10 minutes (in trained athletes). Ingested fluid moves rapidly, so don’t hesitate to keep drinking even towards the end of your workout.


Be wise, fuel well, and enjoy your high energy


Nancy Clark MS RD CSSD

1,924 Views 0 Comments Permalink Tags: hydration, pre-exercise_food, quick_energy, snack

It?s ok to go nuts!

Posted by Nancy Clark RD CSSD Sep 22, 2009

Almonds—and all nuts, for that matter—are a positive addition to a sports diet according to research presented at this year’s annual meeting of the American College of Sports Medicine. For four weeks, elite cyclists enjoyed about 60 almonds a day (~450 calories) prior to meals. They increased their anti-oxidant capacity 43% after a time trial as compared to the group who ate an equal number of calories from cookies. They also improved their time trial distance by 5% compared to the cookie group. The bottom line message is: Food Works!!!


Too often I talk with athletes who are on the “see food” diet. They see food and they eat it. They pay no attention to the quality of the calories, but just to the pleasure. While eating whatever you want may seem a nice reward for hard workouts, the reality is food has a strong impact on both health and performance. The trick is to find quality foods that you totally enjoy. Almonds, anyone? Better yet, slivered almonds mixed with (dried) fruits (apricots, blueberries, pineapple, etc.) and yogurt for a protein-carb combination that both fuels and builds muscles.


Eat wisely and well!

1,130 Views 0 Comments Permalink Tags: health, antioxidants, pre-exercise_food, almonds, nuts

“Nancy, in your Sports Nutrition Guidebook, you mention that athletes can eat within 5 to 30 minutes of exercise and get results. It has always been my understanding that it takes quite a bit of time before food can be digested.  I have been taught that food doesn't leave the stomach for about 2 hours.  I also was under the impression that physical activity, such as running, drew blood away from the stomach thusly slowing down the digestion. Thanks for helping me better understand how to eat pre-exercise.”

Yes, believe it or not, 100 to 200 calories of carbs eaten even 5 minutes pre-exercise can enhance your performance (assuming you can tolerate the light snack). If you were to eat a heavy high protein/high fat meal such as a cheese omelet or cheeseburger, the protein and fat would linger in the stomach and possibly talk back to you. But carbs are readily available, as witnessed when a person with diabetes has low blood sugar and is given some orange juice or cola. That sugar gets into the system within three minutes. The same goes for athletes.

As for blood flow, if you are exercising at a pace you can maintain for more than 30 minutes, you can both digest the food and use it to enhance performance. The trick is to practice pre-exercise fueling, so you learn what foods, and how much of them, will contribute to better performance for your body.

2,447 Views 0 Comments Permalink Tags: pre-exercise_food

Nancy Clark RD CSSD

Nancy Clark RD CSSD

Member since: Jul 8, 2007

Hi! I specialize in nutrition for exercise, and help active people figure out how to manage food, weight, exercise, energy and enjoyment of eating. Let me know if you have any questions!

View Nancy Clark RD CSSD's profile