Some of us are just ordinary mortals. We enjoy a daily 3-mile run, work out at the gym for 45 minutes, participate in an occasional 10K. Others of us are extraordinary athletes -- runners preparing for a marathon, triathletes in training for an Ironman (2.4 mile swim, 112 mile bike, 26.2 mile run), ultra- marathoners spending hours running up and down hills in preparation for a mountain race. As a sports nutritionist, I marvel at the number of runners 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. 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 run. This means less diarrhea, fewer pit stops, more comfort, better performance. Experiment with different foods and fluids to determine what ones settle best: Gatorade or iced tea with honey? Energy bars or gummy bears? Dried fruit or gels? Consuming 200 to 300 carbohydrate-calories per hour of exercise enhances stamina and endurance. Learn how to do it! Some runners believe commercial sports foods are better than natural foods. They are better only if they taste better and digest better. But sometimes, they cause intestinal problems. (Many runners complain 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 burn out" factor. That is, how many gels per hour can you endure in a triathlon? Will you get "sugared-out" on sports drink during the marathon? Think about v-a-r-i-e-t-y.

Tip #2. 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 donut 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. 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 to not only reduce the risk of injury and provide muscles with time to refuel, but 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 long distance runners, feeling overwhelmed by their impending tasks, fill every possible minute with (sometimes poor quality) training. 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. 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 www.eatright.org.

Tip #5. Monitor your urine to be sure you are drinking enough fluids on a daily basis. You should be urinating frequently (every two to four 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 hour-long run during which you consume no fluid. For each one pound of sweat lost, you need to rehydrate with at least 16 ounces of fluid. For example, if you lose two pounds (32 oz.) during an hour of race-pace 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! Many an ultra-runner swears by his Coke and Twinkies. [Editor notes:Twinkies celebrates its 75th year]

Nancy Clark, MS, RD offers personal nutrition 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 Marathoners ($20) are available via www.nancyclarkrd.com or by sending a check to Sports Nutrition Services, PO Box 650124, West Newton MA 02465.