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Optimum Fueling for
Adventure Racing
By Roy Stevenson

Establishing a correct fueling protocol is critical for maximum adventure racing performance. Many adventure racers will tell you their success comes as much from making the right nutritional decisions before and on race day, as doing the right volume and type of training.

Once you’ve done the training for your adventure race, there’s nothing else you can do to improve on it except to follow a tapering program to allow all your hard work to come through.

Your training is all in the bank on race day, but nutrition is where you can improve the most, or conversely, cause problems that will cost valuable minutes or hours, or even lead to a DNF.


What is Adventure Racing?

Caution: Think before you read this. If you open the Pandora’s box, your life may change drastically.

Adventure racing is a combination of two or more endurance events, using orienteering or navigation skills, often including cross-country running, mountain biking, paddling, climbing and related rope skills. Adventure races last anywhere from 6 hours to several days.

The inclusion of several different sports makes it suitable for athletes (or not-so-athletes) from a variety of backgrounds. This is an event in which often the fittest team does not win because adventure racing requires outdoor savvy and mental toughness, as well as great endurance. Speed is not the most important factor.


Establish Fueling Protocols

Maintaining an adequate fluid and food intake during an adventure race is as much an art as a science. Experienced racers will tell you that the best way you can prepare your gastrointestinal system for the fueling challenges of these events is by practicing during training, under simulated ultra running conditions, and during shorter training runs.

Every athlete has their own special nutritional requirements that they have to establish through trial and error because human taste and absorption rates are highly individualized. In addition, the racer also needs to establish the volume of each foodstuff and drink he can handle without adverse side effects.

Many a racer has discovered the hard way that food and fluid choices will vary according to the temperature. Accordingly, you need to practice eating a wide variety of foods in the environmental conditions that you will be competing in. And then there are the small things. Energy bars, for example, harden to the consistency of shoe leather in cold weather, and should be cut into smaller pieces so they can be warmed in the mouth. Store them in zip loc bags. Hot soup might be necessary on a cold day, to provide an easily palatable food while warming you (assuming you have check points and aid stations).


The adventure racer has to establish the following:

- Which sports drinks and liquid meals work and what doesn’t by practicing eating and drinking while training

- What different flavors of sports drink are palatable and how often they should be changed during the event to prevent flavor fatigue

- What foods you can stomach and what makes you feel nauseous Prerace meals that give you the biggest boost

- A carbohydrate loading protocol that works best for you

- How much you can drink and tolerate without feeling liquid sloshing around in your stomach

- Whether salt tablets prevent hyponatremia or whether they simply suck up water from the extracellular spaces, further dehydrating the athlete

- Whether you can tolerate defizzed soft drinks to get a caffeine boost or if they wreak havoc with your blood sugar


Adventure Racing: The Pre-Race Diet


Generally, if you maintain a diet of about 60-70% carbohydrates for at least four days (and follow a tapering program for at least a week) before your event, you’ll boost the glycogen stores in your liver and muscle tissue to a level about twice as high as during normal training and normal diet. This prolongs your ability to maintain a steady pace before fatiguing. A depletion phase where you starve your body of carbohydrates for a few days before starting the carbohydrate loading is no longer considered necessary and can have adverse side effects. The athlete can estimate his desired carbohydrate intake more precisely by calculating 8-10 grams of carbohydrate/kilogram/day. For example, a 72 kilogram (154 pound) runner should take aboard 576 to 720 grams of carbohydrates/day.


Summary—The Pre-Race Diet:
- Stay hydrated before the race
- Carbohydrate load for 3-4 days before
- Consume more sodium and potassium for 3-4 days
- Avoid consuming alcohol for 3-4 days pre-race
- Do not alter the types of foods you are accustomed to before a race
- Eat a high carbohydrate/low fiber snack 1-3 hours before start time


Nutrition During Adventure Racing

Seasoned ultra endurance athletes will tell you to eat before you get hungry, and drink before you’re thirsty. You need to start eating and drinking very early in the race. These are two of the golden nutrition rules of endurance competitions. The basic rule is that the longer the race, the slower you go, and the more you eat.

Solid Foods

Start taking in carbohydrates right from the start, and at regular intervals, to help you conserve the glycogen that you have previously stored in your muscles and liver, for as long as possible. Also realize that no matter how good a job you do of refueling and drinking during an adventure race, you’ll still burn through your stored glycogen towards the end.


Digesting and Absorbing Food and Drink during Adventure Racing

You need to be able to digest, and then absorb, your food and drink. Your food first starts to break down in the stomach, then empties into the small intestine, where the carbohydrates, fats and proteins are absorbed. Ideally, you want your food or liquid to become absorbed as fast as possible to fuel your muscles and brain.


How much food should the athlete take in during an adventure race? Lots! Considering that runners burn 200 to 800 calories per hour (depending on size, gender, temperature, terrain, and intensity of race pace) and that adventure races can last from 6 hours to 24 hours, that’s a lot of grub.

A 150-pound runner going at a moderate pace for ten hours can burn 6,000 or more calories! Next time you’re at your favorite Mexican restaurant have a look at how many plates of enchiladas, tacos, burritos and relenos, plus beans and rice, you have to gobble up to eat this many calories. You’d need to chew your way through half the menu!

A good goal is to take in 1 to 1.5 grams of carbohydrate per kilogram of body weight per hour. For most athletes this will be between 280 to 420 calories for a 70-kilogram (154lb) person per hour. This should include a mix of solids and liquids. Sports nutritionist Monique Ryan, in her book Sports Nutrition for Endurance Athletes recommends 30 to 60 grams of carbohydrate (120 to 240 calories) per hour from sports drinks. Liquid meals in cans like Exceed High Carbohydrate Source, Ensure, Boost, and even chocolate milk can help here.

Recent research has found that sports drinks with combinations of the carbohydrates glucose and fructose, or maltodextrin and fructose can result in reduced fatigue and faster performance. And you can take in up to 90 grams per hour of these mixes.

Lab studies show that we only digest and absorb about 280 calories (or 70 grams) of carbohydrates per hour (Ivy et al 1988) but some evidence shows that we may even be able to take in more than this, up to 800 per hour (Kreider 1991).

Because adventure races are generally at a slower pace (around 60% to 70% of VO2 max) and often conducted at fast walking pace, more blood will flow to the GI tract, enabling faster absorption of food and fluids. Lab studies (Brouns et al 1987) show that exercise at less than 65% of VO2 max does not interfere with digestion, so the adventure athlete should be able to enjoy more solid, higher protein and fat-containing foods like peanut butter sandwiches, cookies, etc.

This makes the adventure race quite unique, in that it is actually an advantage to go at a slower speed for the long haul. So your overall pace needs to be slow enough to permit this to happen.


What Solids Should You Eat?

Most ultra endurance athletes will stock standard carbohydrate rich foods like fruit, watermelon, lightweight fried fruit, bagels, fig bars, energy bars, chocolate bars, cakes, cookies, candy, jelly beans, pretzels, boiled potatoes, pies, even sandwiches (cheese sandwiches seems to be a favorite). But many a competitor has fantasized about and craved Pizza, potato chips, milk shakes and cheeseburgers during the latter stages of their event. Are there some higher fat and protein foods that you can experiment with?

Wrap your foods so that they will not be ruined in wet weather.


Liquids

Ideally you should match your fluid and electrolyte needs with your losses on an hour-by-hour basis. “Ultra runners need to start the race well hydrated”, says Ryan in her book. “This can by drinking 16 to 20 ounces of fluid in the hour before start time”.


Drinking Guidelines for Ultraendurance Athletes 120-250 ml of fluid every 15 minutes = 1 liter (33 ounces) to 2 liters (66 ounces) of fluid per hour


Why the large range in recommended fluid intake? Sweating varies with ambient temperature, humidity, and race pace intensity, gender, and individual sweat rates. Generally, men will need more fluid than women because they tend to be larger and lose more sweat over a larger surface area.

Clearly the athlete cannot carry these volumes of fluid while competing, so the need for a support crew is critical. Fluid stops at drinks stations must be carefully planned, and the athlete must ensure he carries enough fluid between check-points. Most people are able to absorb and process one liter of fluid per hour. An easy guide to whether you are hydrating adequately is to check the color of your urine. If it’s clear, you’re doing well. If it is dark colored, start drinking more. In case you’re wondering, you should be urinating every hour or two.

Beware of sports drinks or soft drinks with high concentrations of carbohydrate (sugar), above 10%. They take longer to empty from the stomach. Remember, you want quick clearance. If you insist on taking such hypertonic sports drinks, dilute them by 50% to play it safe.


To Gel or Not to Gel?
Research has not yet shown that gels are absorbed better than standard sports drinks, which have the advantage of already having carbohydrates dissolved in them in the right concentration.

If you prefer sports gels, avoid washing them down with sports drinks, as the overall concentration will be too hypertonic, and will draw fluid from your gut, further dehydrating you, lowering your blood volume, and making your blood volume more viscous (which makes your heart work harder). Dilute gels with water.


If your adventure race lasts longer than 6 hours, attention must be paid to electrolyte intake, especially sodium through sports drinks or food, to prevent hyponatremia. This is the third golden nutrition rule for ultra running. Hyponatremia occurs in athletes who take in too much low sodium fluid (water) or are excessive sweaters.

If your event takes longer than 6 hours, you’re well advised to experiment with sodium tablets, or foods high in sodium like potato chips or pretzels. There are as yet, no clear-cut guidelines for sodium intake during ultra events, but 200-500 mgs/hour is enough to prevent hyponatremia. It is important that you know the sodium content of your drinks, gels, bars and other foods.

Make sure you take in enough calcium, magnesium and potassium in the days leading up to the race. Although the evidence is inconclusive, these electrolytes may have an effect on preventing muscle cramps, one of the most dreaded afflictions that can sideline endurance athletes. Once you have cramps, it’s all over.

Some athletes take Rolaids (calcium and magnesium) to ensure these minerals are topped up, but again, you should make sure you try these during your extended training simulations.


Flavor Fatigue
An interesting nutritional phenomenon often happens under the stress of ultraendurance competition. Many athletes find they cannot continue to stomach their favorite drink (or foods) throughout the event. Nutritionists refer to this as “flavor fatigue”, meaning you can no longer tolerate your favorite foods or beverages.

How to Avoid Flavor Fatigue

Prepare and pack several different flavors of your favorite drinks, gels, bars and other foods that have proven tolerable in the past. Different flavored drinks should be alternated at check points right through the event so you don't get tired of the same flavor.


Summary for Fueling for Adventure Racing

After practicing eating a variety of foods during extended training runs, the athlete can now select foods and fluids for the ultra race. Acccording to sports nutritionist Nancy Clark et al (1992), MS, the ultraendurance athlete must . . .

- Have a defined feeding plan. Both the athletes and crew should have a written nutrition program that outlines the times and amounts of fluids and foods.
- Be flexible and open-minded. Have many alternative foods available in case the tried-and-true foods are not working out. Eat a variety of foods rather than a limited number of items.
- Cooperate with the support crew. You must relinquish your authority and follow the crew’s directions when it is clear that you need refueling.
- The crew should keep diet forms that record the food and fluid intake of every person on the team, preferably for each hour, and also detail the frequency of urination. If you’re urinating every 30 minutes, you are probably drinking too much fluid.
- Select a crew leader who is well organized, a good motivator, and an enforcer of regular feedings

References

Brouns, F, W.Saris, and N. Rehrer. 1987. Abdominal complaints and gastrointestinal function during long-lasting exercise. International Journal of Sports Medicine 8:175-189

Clark N, J.Tobin, and C.Ellis. 1992. Journal of the American Dietetic Association. Vol.92:40, PP.1258-1262

Ivy, J. A. Katz, C.Cutler, W.Sherman, and E.Coyle. 1988. Muscle glycogen synthesis after exercise: effect of time of carbohydrate ingestion. Journal of Applied physiology. 64:1480-1484

Kreider, R. 1991. Physiological considerations of ultraendurance performance. International Journal of Sports Nutrition. 1:3-27

Tarnopolsky, M. Adventure Racing and Ultramarathons. Summary for 2008 Sports Nutrition Conference, Indianapolis, Indiana. Hosted by University of Birmingham, England.

Other references

Clark, Nancy. MS. 1995. Nutrition and Exercise Workshop. Seattle, Washington. August 25, 1995.

Eberle, S. 2007. Endurance Sports Nutrition. Human Kinetics Publishers, Champsign, Illinois. 2nd Edition.

Ryan, Monique. 2007. Sports Nutrition for Endurance Athletes. Velo Press., Boulder, CO. 2nd Edition.


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