What should I eat before I exercise?

What should I eat before I exercise? is the most common question athletes ask me, a sports nutritionist. The answer varies, depending on:

–how hard you will be exercising. Before intense the exercise, you’ll want just a small lowfat snack that digests quickly, such as a half a bagel—as opposed to a whole bagel with peanut butter.

–how well your intestinal tract tolerates food. Some people have cast-iron stomachs and can eat anything pre-exercise, without fear of intestinal distress. Others need to wait a few hours.

–how long you will be exercising. If you plan to exercise for more than 60 to 90 minutes, eating a pre-exercise meal or snack will enhance your stamina and endurance. Pre-exercise food is less important before a 30-minute exercise session (assuming you are not hungry.)

Because each person has a unique response to pre-exercise food, you will want to experiment with a variety of options. Carbohydrate-based foods (such as bread, watermelon, boiled potato) digest easily and are generally the best options. Some popular choices include:

  • Toast (or a bagel) with jam or peanut butter
  • Banana
  • Cereal with lowfat milk
  • Oatmeal with raisins
  • Granola bar
  • Fruit smoothie (made with 1 large banana, ½ cup berries, ½ cup low-fat milk or yogurt) and ice cubes.
  • Pita with hummus

Most active people easily tolerate 200 to 300 pre-exercise calories before a 60-90 minute workout; the fuel helps keep blood sugar from dropping and abates the appetite. No need to exercise hungry! If you want to get mathematical, target about 2 calories of carbohydrates per pound of body weight (0.5 g carbs per lb). That means, if you weigh 150 pounds, you want approximately 300 calories (more or less) in carbohydrates.

Adding a little fat or protein to the snack 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, and contribute to discomfort. While a few nuts in a handful of trail mix can be fine, the dried fruit is the better energizer.

Some people with digestive concerns allow three to four hours between fueling and exercising; others can eat and exercise five minutes later. You may want to allow 2 to 3 hours after a moderate-sized pre-exercise meal to allow enough time for digestion and absorption. You can likely tolerate a smaller (200 to 300 calorie) snack within an hour pre-exercise. If you don’t have any trouble exercising with food in your stomach, you can shorten this window to five minutes! And as long as you are exercising at a pace that you can maintain for more than half an hour, your body can digest the food and use it to fuel your workout.

If pre-exercise food “talks back to you,” start with small amounts of food (a cracker or a piece of banana), so you can train your GI tract to accept some fuel. Even a little food can improve energy and performance. Some people choose a sports drink because it feels less heavy in the stomach.  The overall goal, however, for exercise longer than 60 to 90 minutes, is to train your body to be able to tolerate a pre-exercise snack or meal. You cannot run a marathon on air!

For more information: Nancy Clark’s Sports Nutrition Guidebook 

Sandcastle Contest Winner: Honoring USA Women’s Soccer

Sandcastle Contest Winner: Honoring USA Women’s Soccer

In honor of Team USA, my “team” of family and friends built this award winning sandcastle at the Sand Castle Contest last weekend.

Girls Rock! Congrats Team USA

Girls Rock!
Congrats Team USA

The soccer ball is made with two colors of sand … the black sand was pretty stinky, but a fun time was had by all.

Team USA worked hard and deserve all the congratulations they are getting. Inspirational!


If you want nutrition information that will help get your team into the winners’ circle, take a look at Food Guide for Soccer: Tips and Recipes from the Pros!

Electrolyte replacers: Do athletes need to buy them?

Electrolytes are electrically charged particles, most commonly known as sodium, calcium, magnesium, and potassium. They are abundant in “real foods” – including fruits, vegetables, grains, meats, and dairy foods. These real foods are generally far less expensive electrolyte replacers. Continue Reading

Salt, Sodium, and Summer Sweat

It’s summer sweat season! If you will be exercising hard for more than two or three hours in the heat and losing a lot of sweat, you might be wondering how to best replace the water and electrolytes lost along with the sweat. Here are a few tips to enhance your sports nutrition knowledge and guide your choices.

  • A pound of sweat contains about 16 ounces of water and 500 to 700 milligrams (mg) of sodium. Sodium is a part of salt.
  • Sodium is a mineral that is also called an electrolyte (electrically charged particle). It is one part of salt; chloride is the other part.
  • Sodium helps retain water in your body. If you drink plain water, it goes in one end and out the other. But adding a little bit of sodium (or drinking water with a food, most of which contains sodium) enhances fluid retention.
  • In hot weather, eating salty foods before you do extended exercise gets sodium into your system and invests in your ability to stay better hydrated.
  • In a 2-hour hard aerobic workout, you could potentially lose 1,000-2,000 mg sodium. After two hours, you goal is to replace about 500 mg. sodium per hour.
  • The body of a 150-lb person contains about 92,000 mg sodium.

You do not need to buy expensive electrolyte products to get adequate sodium, even in hot weather. The typical sports diet offers more than enough! Yet, if you are craving salt, you should consume salt.


Food                                        mg Sodium      Comments

Chicken noodle soup              2,350               Campbell’s, 1 can

Salt, 1 tsp.                               2,325               Sprinkle on food pre-exercise

The Right Stuff                       1,780               $$$ sports supplement

Ramen Noodles                       1,660               Mauchan, 1 block

Bacon, egg & cheese bagel       1,340               McDonald’s

¼-pounder w cheese               1,100               McDonald’s

Chicken bouillon cube             1,100               Low cost “electrolytes”

Salt packet                                   270               From a fast food restaurant

Chocolate milk                            150                8 ounces

Gatorade                                      110                8 ounces

The bottom line:

If you are an athlete who sweats heavily, you want to eat salty foods before you embark upon your exercise program. During sweaty exercise that lasts for more than 2 hours, you want to drink plenty of water with sodium-containing snacks (muffin, beef jerky, bagel, cheese stick or endurance sports drinks), and eat extra salt afterwards if you are craving salt. No need to purchase “electrolytes” because you can get plenty in processed foods. If you eat only “all natural” foods with few wrappers, bring out your salt shaker!

For more information: Nancy Clark’s Sports Nutrition Guidebook

Too nervous to eat?

Too nervous to eat?

Are you among the plethora or athletes who gets the pre-event jitters? I’ve talked with many a figure skater, baseball pitcher, and runner who feels unable to eat before a competition. Unfortunately, performance problems start when nervous energy (from adrenaline) becomes unable to sustain top performance. Continue Reading

Should I eat before a morning run?

Should I eat before a morning run?

I run at 5:30 in the morning and generally don’t eat anything. I’ve read that I shouldn’t run on empty. If there were just one food to eat—easily digestible—which one would you recommend? Continue Reading

Wanted: Host sites for my sports nutrition workshop

For my next Fall-Winter workshop series, I am looking for a medical facility, health club or university that would enjoy hosting “Nutrition for Sports, Exercise & Weight Management: What Really Works and Why.” I co-lead this workshop with exercise physiologist John Ivy.

We would like to hold the workshop in the vicinity of :

Boston and Providence – sometime in November and December 2015

Washington DC– sometime in January, Feb or March 2016

If you know of a facility with a conference room/lecture hall that holds about 100 people for this workshop please contact me at

The workshop schedule is Friday (8:00 to 4:30) and Saturday morning (7:00 to 12:30), We trade the room for some free registrations for the staff at the facility.


Nancy Clark

Half vs. Full Marathons: Fueling differences?

Q. I am new to running and am training for my first half-marathon. Is there a difference between fueling for a half-marathon vs. a full 26.2-mile marathon?
A. One difference relates to burning about 1,300 calories (half-marathon) vs. 2,600 calories (full marathon). The marathoner also has an easier chance of becoming dehydrated, might need more sodium, and perhaps wants a caffeine-boost along the way. Continue Reading

How much junk food (if any) is OK to eat?

While some people try to avoid any form of a sweet treat, salty snack or other form of so called “junk food”, others wonder how much they can eat without creating nutrition and health problems. For my clients, I suggest they enjoy a healthful sports diet that targets 85 to 90-percent of calories from quality foods and, if desired, 10 to 15-percent from “whatever.” Some days “whatever” might be carrots and other days it might be (guilt-free) carrot cake with cream cheese frosting. If you have trouble with eating too much junk food, the problem is not sugar and sweets but rather, you have likely gotten too hungry. You can resolve afternoon junk-food cravings by eating heartily at breakfast and lunch.

Given that you can ingest the recommended intake of all the vitamins, minerals, and protein you need within 1,500 calories from a variety of wholesome foods, a hungry athlete who consumes 2,000 to 4,000 calories a day has the opportunity to consume LOTS of nutrients. For example, 8 ounces of orange juice offers 100% of the Recommended Dietary Allowance (RDA) for Vitamin C. A thirsty runner who chugs the whole quart can consume 4 times the RDA in that one snack. OJ is better than an all-natural vitamin pill! Hence, a few hundred calories of “junk food” has little negative impact in the context of the whole diet.

Should athletes try to avoid refined sugar?

Refined white sugar is a nutritional zero, void of any vitamins, minerals or protein. Yet, the calories in sugar come from carbohydrates. Muscles welcome these carbs to fuel depleted glycogen stores. Muscles don’t know the difference between carbs from juice, candy, and sports drinks vs. apple, sweet potato, and banana. The difference shows up in health, immune response, and ability to fight off colds and flu. Continue Reading

How to Help Your Overweight Child

Q. “My son is chubby. What can I do to help him lose weight..?

A. How to help an overfat child lose weight is a complex topic of debate among parents and pediatricians alike. We know that restricting a child’s food intake does not work. Rather, restricting food tends to result in sneak-eating, binge-eating, guilt, shame–the same stuff that adults encounter when they “blow their diets.” But this time, the parents become the food police—an undesirable family dynamic.

The following tips are based on information from books by family feeding expert Ellyn Satter: Your Child’s Weight: Helping Without Harming and Secrets of Feeding a Healthy Family.

Food restrictions cause problems

Despite your best intentions to prevent creeping obesity, do not put your overfat child on a diet. Diets for children disrupt a child’s natural ability to eat when hungry and stop when content. Instead, the child overcompensates and doesn’t stop when he’s content (binges) or stuffs himself with “last chance eating.” You know, “Last chance to have birthday cake so I’d better eat a lot now because when I get home, I’m restricted to celery sticks and rice cakes.”

If you are a parent of a chubby child, note that children commonly grow out before they grow up. That is, they often gain body fat before starting a growth spurt. Instead of putting your daughter on a diet (which damages self-esteem and imprints the message she isn’t good enough the way she is), get her involved in sports and other activities. If your child expresses a desire to learn how to eat better, arrange for a consultation with a registered dietitian who specializes in pediatric weight control. (Use the Academy of Nutrition and Dietetics’ referral network at

Is your child really overfat?

Often, the child’s weight problem is really the parent’s issue. You may want a “perfect child.” Talk to your pediatrician to determine if your child’s weight is indeed a health issue.

Be sure to love your overfat child from the inside out–and not judge her (or him) from the outside in. Just little comments (“That dress is pretty, honey, but it would look even better if you’d just lose a few pounds…..”) get interpreted as “I’m not good enough.” Self-esteem takes a nose-dive and contributes to anorexic thinking, such as “thinner is better.”

Weight management tips

So what can you do to help fat kids slim-down? Work together as a family to change your food and exercise habits. This could mean watching less TV, planning enjoyable family activities (unlike boot camp), and perhaps even creating a walking school bus with the neighborhood kids. As a family, you might want to sign up for a charitable walking or running event

Food-wise, provide your kids with wholesome, nourishing foods, as well as semi-regular “junk foods.” (Otherwise, they will go out and get them). Encourage them to eat breakfast. Plan structured meals and snacks; take dinnertime seriously. Your job is to determine the what, where and when of eating; the child’s job is to determine how much and whether to eat. (That is, don’t force them to finish their peas, nor stop them from having second helpings.) Trust them to eat when hungry, stop when content—and have plenty of energy to grow and enjoy an active lifestyle.

Sports dietitian Nancy Clark, MS, RD has a private practice in the Boston area, where she counsels both casual exercisers and competitive athletes (617-795-1875). Her best-selling Nancy Clark’s Sports Nutrition Guidebook is available at See also for online education.