Athletic ability, proper training, old injuries, and even genetics can affect your performance on the slopes. But did you know that diet plays just as important role as any of these variables? What you eat and drink can enhance your skiing or snowboarding performance-particularly at advanced levels--so read on for insights into which nutrients are most useful before, during, and after a day on the slopes.

Most people realize it takes stamina to ski or ride all day, but not everyone makes the connection between energy and diet. If you maintain your fitness level year-round, are injury free, and ski or ride proficiently, but still feel as if you're about to keel over after a day on the slopes, the problem could be your diet regimen.

These days, there's no shortage of information on how to boost personal performance, but it's often difficult to distinguish the hype from the truth. The fact is, preparing for a day on the mountain isn't all that complicated. This article offers advice to help you maintain your energy reserves, increase your performance levels, and prepare for the day that follows. What you need to do is get fueled, stay fueled, and refuel!

Getting Fueled

What, how often, and how much you eat can have a major influence on your ability to put in a full day on the slopes. This is the best way to ensure that you are not left without energy for your last run or the last gate of the day. Proper diet can prepare you for peak performance on a regular basis, and research indicates that carbohydrates are the food of choice for high-level physical activity.

Carbohydrates are your best source for energy because they work to help muscle cells (as well as liver cells) maintain maximum capacity at all times by replacing the cells' energy stores during and after physical activity. Carbohydrates also help keep blood sugar at appropriate levels during exercise.

An ideal high-performance diet derives 60 to 70 percent of its calories from carbohydrates, with the majority of those calories coming from "complex" sources--carbohydrates that release their energy-producing sugars at a slower rate than the "simple" carbohydrates found in refined sugar and white bread. Complex "carbos" are found in grains, rice, pasta, fruits, and vegetables. Milk and dairy products also serve as a good source of carbohydrates. For the balance of a high-energy diet's calories, less than 30 percent should come from fats and only 10 to 15 percent from proteins.

In establishing parameters for healthy eating habits, dietary experts have long recommended an intake of 2,000 calories per day for active, average-sized individuals. Applying the above highperformance criteria to this "reference diet," a minimum of 1,200 of those calories (or 300 grams) would be in the form of carbohydrates. The National Research Council of the U.S. Department of Health and Human Services by way of its Recommended Dietary Allowances (RDA) provides the guidelines for the best combination for the consumption of carbohydrates (see table 1 below). The RDA calls for nine servings of starches (i.e., breads, grains, or rice), five servings of vegetables, four servings of fruit, and three servings of dairy products each day. Your daily intake of protein should include 5- to 6-ounce servings of lean meat, fish, or chicken; vegetarians may substitute soy products, nuts, seeds, and eggs as necessary. (Depending on body size and activity levels, some people may require more than 2,000 calories per day to maintain energy, and for this purpose table 1 also provides a chart for a 3,000-calorie daily diet.)

This dietary pattern will give you more than 50 percent carbos, less than 30 percent fats, and more than adequate amounts of protein. And best of all, there's still a little leeway for cookies and ice cream. Following this type of diet will help you get off to a great start and provide you with adequate fuel on a daily basis.

Getting Hydrated

As they say, you cannot live by bread alone, so be sure to take care of the liquid side of your diet as well. While following a high carbo diet, you need to make sure that you drink a minimum of 2 or 3 quarts of water each day to remain hydrated.

Because it is effective, inexpensive, and easily absorbed by the body, water is still the best fluid replacement drink for activities that last less than an hour. For activities that last more than an hour, however, fluid replacement drinks are also acceptable specially those that contain between 6 and 8 percent carbohydrate solution (i.e., 60 to 80 grams of carbohydrates for each 8 fluid ounces). These fluid replacement drinks should also contain electrolytes such as sodium, potassium, chloride, and magnesium as well as the antioxidant vitamins C and E. Electrolytes help prevent muscle cramping and will maintain fluid balance and nerve impulse transmission. Antioxidants may help prevent muscle damage due to intense exercise. Other ingredients to look for on the label of a fluid replacement drink include B vitamins and the amino acid called glutamine, both of which may be beneficial in restoring fluid and energy balance at the cellular level.

In The Ultimate Sports Nutrition Handbook, dietician and exercise physiologist Ellen Coleman writes that the optimum pre-snowsports meal should consist of 300 to 400 calories (75 to 100 grams) of carbohydrates consumed one to two hours before you hit the slopes. However, if you're an early riser and plan to eat more than four hours before you begin your day on the mountain, you need to consume 700 to 800 calories (175 to 200 grams) of carbohydrates. To make sure that you're hydrated, "top off" your tank by drinking 8 to 16 ounces of water or fluid replacement beverage at least 15 minutes before you start. If you can follow these simple steps, you're well on your way to a great day on the hill.

Staying Fueled

Now that you have a general sense of the overall dietary game plan and know what to eat and drink before you hit the slopes, it's time to focus on maintaining that energy through your last run. Eating and hydrating during activity is critical, especially while you're participating in snowsports that require high levels of energy throughout the day.

To keep your energy reserves full, try to eat 30 to 60 grams of carbos per hour while you're on snow (see table 2 below). Energy replacement bars and carbo/fluid replacement drinks are convenient ways to refuel. For best results, consume products that are easily digestible so that they can enter the system quickly.

As for fluids, they are every bit as vital as food. You should consume fluids at the rate of 4 to 8 ounces for every 15 minutes that you're active. That number works out to between .5 and 1 quart of fluids per hour. just as energy is needed to fuel the muscles, fluid is necessary to prevent compromising cardiac and muscle functions. When you are dehydrated, your heart has to work harder and the muscles in your body do not contract as efficiently as they do when they are sufficiently hydrated.

Paying attention to your energy level throughout the day will help you determine if you're eating enough to sustain your activity. Moreover, proper fluid intake will prevent the dehydration that can sap your energy output. You can check your hydration level by inspecting the color of your urine: if it's clear or light yellow, you're properly hydrated.

Staying fueled and hydrated throughout the day will improve your chances of performing well on snow. Make sure that the body gets fueled on a regular basis and stays fueled with proper diet and fluid intake. You'll feel the difference!

Refuel

Now that your day on the slopes is over, you can kick back and relax, right? Wrong! What you eat and drink within two hours of coming off the hill can have a huge impact on capacity for highenergy performance the next day.

Researchers have identified optimum times for rehydrating and replenishing energy levels after physical exertion. In the books Eating for Endurance by Ellen Coleman and Optimal Muscle Recovery by Edmund Burke, the authors indicate that there is a "window of opportunity" for replacing the lost energy and fluids in order to prepare to perform at high levels the following day.

The first window of opportunity to refuel your system is approximately 15 to 30 minutes after you leave the slopes, and many sports nutritionists recommend consuming 1 gram of carbos for each pound of your body weight during this period. If you weigh 150 pounds, that means you should consume 150 grams of carbos. Adding some protein to this apres ski snack is also a wise idea because it can help you begin repairing muscles damaged during exercise.

It doesn't matter whether you choose solid or liquid food (for instance, carbo drinks or soups) for carbohydrate energy replacement, but the type of carbohydrate should be one that has a high glycemic index, such as a bagel, baked potato, rice, bread, or cereal. The glycemic index of food indicates the rate at which the carbohydrates can be ingested and the effect that particular type of carbo has on blood glucose levels. Other high glycemic carbo sources include honey, molasses, maple syrup, and sports drinks sweetened with either sugar or corn syrup.

At the end of a strenuous day, there's a good chance that your appetite will be suppressed in the wake of intense exercise. Because of this loss of appetite and because fluids are easier to digest, many people actually prefer to consume a "liquid meal" consisting of a carbohydrate/ fluid replacement drink.

A second window of opportunity for recharging your batteries will open two to four hours after coming off the slopes. Your appetite should be back now, and the meal you have at this time should consist of solid food. Moreover, it should follow the previously suggested ratios for your diet: 60 percent or more carbos, less than 30 percent fats, with a minimum of 10 to 15 percent proteins. Getting back into this eating pattern will help start your cycle of consumption all over again as you prepare for another high-performance day on the slopes.

Remember to continue hydrating at the rate of 16 ounces for every pound of weight lost during activity. It's not be unusual to lose 5 to 7 pounds of water during a day of hard skiing or snowboarding, so weighing yourself before and after a strenuous day of snowsports; is recommended. For rehydration, water is great, but a fluid replacement drink with a 6- to 8-percent carbohydrate solution containing the appropriate electrolytes may be a better choice because it will also have some carbohydrates included.

Also, if you're going to take a day or two off from skiing or riding, it's a good idea to reduce your calorie intake a bit while still ingesting a balanced diet. And as always, stay hydrated.

Conclusion

Imagine your body is a train with a steam engine. A regular supply of the right fuel will keep the fire in the engine burning, moving the train powerfully ahead. If you forget the fuel, the train will never make it out of the station, and if you neglect to keep the fire stoked, your engine's bound to lurch along at a slow crawl. Want to keep your locomotive on track all day, every day? Proper nutrition and hydration are the tickets to success.

Glen Peterson, Ph.D., is the ski school director for the Hyland Hills Ski/Snowboard Area in Bloomington, Minnesota. He is also a professor in the Health/ Physical Education Department at Century College in White Bear Lake, Minnesota.

References

Burke, Edmund. 1999. Optimal Muscle Recovery: Your Guide to Achieving Peak Physical Performance. Garden City Park, NY: Avery Publishing Group.

Coleman, Ellen. 1997. Eating for Endurance. Palo Alto, Calif.: Bull Publishing.

Coleman, Ellen. 1996. The Ultimate Sports Nutrition Handbook. Palo Alto, Calif.: Bull Publishing.