Eating for Endurance

Some of us are just ordinary mortals -- we enjoy a daily three-mile run, workout at the gym for 45 minutes, play volleyball once a week at the Y.

Others of us are extraordinary athletes -- cyclists preparing for a double-century ride (200 miles), triathletes in training for an Ironman (2.4-mile swim, 112-mile bike, 26.2-mile run), mountain marathoners spending hours running up and down hills in preparation for a race.

As a sports nutritionist, I marvel at the number of people who push themselves to the limit. But I am dismayed at how many fail to make nutrition an integral part of their training program.

They get their training down pat but miss an important link -- fueling well.

My job is to help these athletes optimize their eating despite their busy lifestyle.

If you have high expectations from your body, this article can help you fuel at your best, so you can train at your best, so you can compete at your best.

The information can also help ordinary exercisers who struggle to find energy to simply survive this marathon called life.

Tip #1: Eat during training

Make "eating" an integral part of your training program -- not an afterthought. By practicing fueling your body during exercise (as you will be doing during your endurance event), your intestinal tract will learn to manage food while you exercise. This means less diarrhea, fewer pit stops, more comfort, better performance.

Experiment with different foods and fluids to determine which ones settle best: Gatorade or iced tea with honey? Energy bars or peanut butter and raisins wrapped in a tortilla? Bananas or gels?

Consuming 200 to 300 carbohydrate-calories per hour of exercise enhances stamina and endurance. Learn how to do it!

Some athletes believe commercial sports foods are better than natural foods, but they are better only if they taste better and digest better. Sometimes, they cause intestinal problems. (Many athletes, for example, complain that gels cause diarrhea.)

During training, develop a menu of tried-and-true foods that digest well and taste good. This food may be the most pleasant part of your exercise experience; choose it wisely!

Also think about the "taste bud burnout" factor. That is, how many gels per hour can you endure in a triathlon? When hiking, how many days in a row will you enjoy peanut butter? Will you get "sugared-out" on sports drink during the century bike ride?

Think about v-a-r-i-e-t-y.

Tip #2: Plan your diet

Schedule time to food-shop, so you can optimize your daily food intake.

All too often, in the midst of juggling work, family, friends, sleep and training, endurance athletes find no time to plan meals and shop for (or otherwise obtain) a well-balanced sports diet.

The result: yet another doughnut for breakfast, cookie for lunch, vending machine snack, and a fast 'n' fatty meal that fills the stomach but leaves muscles poorly fueled.

Muscles need carbohydrates for fuel: GrapeNuts, oatmeal, granola, bagels, fruit, juice, hearty breads, bean burritos, spaghetti. Your job is to eat carbs evenly throughout the day (as opposed to skimping on meals by day, then gorging on treats at night).

By having breakfast, a mid-morning snack, lunch, and an afternoon snack, you'll have steady energy all day, without lags.

Make time to develop an eating strategy that fits your training schedule. For example, one triathlete devised this routine: he drank a tall glass of juice (i.e., carbs) before his morning swim, refueled afterwards with breakfast in his car while commuting to work (big bagel with peanut butter, milk in a travel mug, banana); ate a hot dinner at noon (from the cafeteria at work).

At noon, he also bought his afternoon snack (muffin, juice) and his evening meal (turkey sub, yogurt); he kept these in the office refrigerator.

This program prevented the evening "junk eating" that happened when no healthful food was conveniently waiting for him once he finished his second workout of the day and was too ravenous to cook.

Tip #3: Take rest days

Erase the thought "I'm lazy if I take a day off." Taking a rest day is being smart, not lazy!

Rest days are essential, not only to reduce the risk of injury and provide muscles with time to refuel, but also to allow time for you to food-shop (and even cook a big pot of chili for the week, if so inclined).

Performance improves when you do quality exercise, not excessive quantity of exercise. Yet too many ultra-distance athletes, feeling overwhelmed by their impending tasks, fill every possible minute with (sometimes poor quality) exercise.

They become exhausted, if not sick. Take note: You have a better chance of beating your competitors if you enter the event well-rested, not overtrained. Don't be one to lament "I wish I had rested more before my event ..."

Tip #4: Ask an expert

Consult with a sports dietitian who can tell you: how many calories you need to fuel up, fuel during and refuel after your workouts; how many grams of protein you need to build and repair muscles; how many protein bars (if any) you need.

This "food coach" will create a personal fueling plan that prevents (or delays) fatigue and optimizes recovery.

To find a sports dietitian, put your ZIP code into the referral network at

Tip #5: Monitor hydration

Monitor your urine to be sure you are drinking enough fluids on a daily basis. You should be urinating frequently (every 2 to 4 hours); the urine should be light-colored, like lemonade. Smelly, dark urine signals dehydration. Bad.

To help you drink more, keep a quart of ice water on your desk or juice boxes in your car.

During training, learn your sweat rate: weigh yourself naked before and after an hourlong workout during which you consume no fluid. For each pound of sweat lost, you need to rehydrate with at least 16 ounces of fluid.

For example, if you lose 2 pounds (32 oz.) during an hour of training in weather similar to that anticipated on race day, your target race-day fluid intake should be at least 32 ounces per hour (8 ounces every 15 minutes).

Tip #6: Be flexible

Tastes change during exhausting exercise. Tired athletes commonly resort to sweets and "junk" -- but that can be OK as long as the fuel settles well.

Even lackluster treats can delay fatigue and provide comfort when you need it the most!

Copyright January 2005, Nancy Clark, MS, RD

Nancy Clark, MS, RD offers personal consultations to endurance athletes and ordinary mortals at Healthworks (617-383-6100), the premier fitness center in Chestnut Hill MA. Her "Sports Nutrition Guidebook" ( $23) and "Food Guide for Marthoners" ($20) are available via or by sending a check to Sports Nutrition Services, PO Box 650124, West Newton MA 02465.

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