The Paleo Diet for Athletes (6 page)

Take in mostly carbohydrate.
As was explained in the previous section, during the multihour fast of your night’s sleep, your body’s stores of glycogen were reduced. The fastest, most efficient way to restore this vital fuel source is by eating carbohydrate. If chosen wisely, carbohydrate also has the advantage of digesting fairly quickly so that you won’t be carrying a load of undigested foodstuffs early in the training session or race. The type of foods to eat will be addressed shortly.

The more time before the start of the race or workout, the more you should reduce the glycemic index of the meal. The glycemic index of a food indicates how quickly a carbohydrate’s sugar gets into the blood. A quick release of sugar from the meal triggers the release of the hormone insulin by the pancreas. This results in a rapid decrease in the blood
sugar level, followed quickly by increased hunger shortly before the race begins. That’s not what you want to happen. But by eating a lower glycemic index food 2 or more hours before starting, your gut will have time to digest it and slowly replenish glycogen stores. Fruit, for example, is a good choice because its sugar, fructose, is slow to digest, lowering the glycemic index.

Keep the meal low in fiber.
There are several ways to reduce the glycemic index of a food. One of the most effective is the addition of fiber. But this may be too effective for a preexercise meal; the fiber in some foods, such as coarse, whole-grain cereals, is so dense that it could well sit in your gut for several hours, soaking up fluids and swelling. That’s not a good feeling to have at the start of a race or hard workout.

Include protein, especially the branched-chain amino acids.
Amino acids are the building blocks of protein. Certain amino acids, the “essential” ones, are critical for your health and fitness and must be in the foods you eat because the body can’t produce them. Research out of the lab of Peter Lemon, PhD, at the University of Western Ontario reveals that three of these essential amino acids, those called branched-chain amino acids (BCAA), have benefits for performance when taken before aerobic exercise. (If you study protein for athletes, you’re sure to come across Dr. Lemon’s name often, as he is considered one of the leading authorities in the world on this topic.) In this study, cyclists were given 6 grams of BCAA or 6 grams of gelatin 1 hour before an exhaustive session on a bicycle. Compared with the gelatin feeding, the BCAA significantly improved time to exhaustion and maximum power output, while lowering heart rate at submaximum efforts. Blood sugar and lactate levels did not differ between the two trials.

Other research has revealed that a mixture of the essential amino acids and carbohydrate taken before strenuous exercise not only improves endurance performance but also effectively stimulates protein synthesis after exercise. This is great news for the serious endurance athlete, as time to recovery is critical for performance. The faster you recover, the sooner you can do another quality workout; the more quality workouts in a given period of training, the better your subsequent performances in races.

Finally, an additional benefit of adding protein to a preexercise meal is that this lowers the glycemic index of the carbohydrate ingested along with it. A lowered glycemic index means a longer, slower release of sugar into the bloodstream during the subsequent exercise session, thus delaying the onset of fatigue.

Drink to satisfy thirst.
You can prevent dehydration during exercise by making sure that you are well hydrated before starting. Furthermore, research has shown that consuming adequate fluids relative to thirst reduces protein breakdown during exercise. Anything you can do to spare protein or prevent its use as a fuel during a race or workout benefits both performance and recovery. You don’t want to use muscle tissue to fuel exercise. Drinking to satisfy thirst before exercise is one simple way to help ensure this doesn’t happen.

Take in water only in the last hour.
The purpose here is to prevent a rapid influx of sugar to the blood, followed by the release of insulin to control it. Such a sugar-insulin (hypoglycemic) reaction is likely to leave you low on blood sugar at the start—just the opposite of what you intended—so you feel slightly dizzy and light-headed within a few minutes of starting exercise.

The exception to this guideline is that in the last 10 minutes prior to exercise, high glycemic index fluids may be consumed. This is explained in greater detail below.

Preexercise Food Choices

Foods to eat before exercise should be those that can be found in grocery stores, no matter where you are racing, or easily be carried during travel. The following are examples of such food sources to eat prior to the last hour before starting exercise. You should select those that appeal to you in the morning and are well tolerated by your body. Try them on the days of race-simulation workouts and priority C races, well before the targeted priority A event for which you intend to use them. You may want to combine two or more of these to create some variety in your preexercise meal.

Fruit with eggs.
Eggs are loaded with protein and easily digested by most people. Boiled eggs may be taken to a race venue if they are kept chilled, or you can order scrambled eggs at a restaurant. One large, whole egg contains about 6 grams of protein and 1.5 grams of BCAA. Combine this with fresh fruit, especially fruit that is low in fiber, such as bananas, peaches, cantaloupe, honeydew, and watermelon. Fibrous fruits to avoid include apples, berries, dates, figs, grapes, pears, mango, papaya, and pineapple.

Applesauce mixed with protein powder.
Look for unsweetened applesauce. This is low in fiber and has a low glycemic index primarily due to its fructose content, and it’s well tolerated by most people. Stir in 2 or 3 tablespoons of powdered egg or whey protein to further slow the glycemic reaction and to add BCAA. The BCAA content of protein powders varies with source and manufacturer, but they contain roughly 2.2 grams per tablespoon. Carry protein powder in a plastic bag when traveling to races and purchase applesauce at your destination. While this doesn’t exactly sound like a gourmet meal, realize that you are eating before the race only to provide fuel for your body. Be sure to try this in training or before a priority C race.

Baby food, including animal products.
This may sound strange, but it works well. Chopped and pureed baby food can be found anywhere and is easily digested by the human gut at any age. Good choices are fruits or vegetables, along with chopped meats such as turkey, fish, or chicken.

Liquid meals.
If you tend to have a very nervous stomach prior to races, blending foods may produce a liquid you can more easily digest. Blend low-fiber fruit, such as those listed above, with fruit juice and 2 or 3 tablespoons of powdered egg or whey protein.

Commercial meal-replacement drinks, although not optimal, are an option when you are away from home and don’t have any other options for real food. Look for products with added protein, such as Ensure High Protein. It’s best to avoid those drinks that use milk as a base. Whey protein as an ingredient, however, will meet your protein needs for the prerace meal. Be aware that these drinks are becoming so popular
with endurance athletes that stores in the vicinity of races often sell out days in advance. Bring your own or shop early.

Sports bar with protein.
This is the least attractive of the options, but it’ll work in a pinch. Protein bars, sometimes called meal-replacement bars, are easily carried and available almost everywhere. While primarily a carbohydrate-based food source, they contain just enough protein to slow the glycemic reaction and add some BCAA to the meal.

Fluids, especially water.
You may also use coffee or tea, which have known benefits associated with caffeine. As little as 1 or 2 cups (depending on body size) of strongly brewed coffee, which has about 3 times as much caffeine as tea, before exercise has been shown to improve endurance performance in athletes who are not chronic users. However, be aware that there are potential downsides with caffeine, such as upset stomach and increased nervousness. Most studies have found that caffeine is not a diuretic. The need to urinate after drinking caffeinated drinks probably has to do with drinking beyond thirst. The World Anti-Doping Association (WADA) does not consider caffeine to be a prohibited substance, while the International Olympic Committee (IOC) as of 2008 enforces a limit of 12 mg per liter of urine. It would take most athletes 6 to 8 cups of strong coffee to reach this level.

Fruit and vegetables juices may also be taken in before exercise, but not in the last hour prior. Be sure to experiment with these during training sessions. Good choices are tomato, apple, and orange. Tomato juice often has added sodium, which may increase your thirst and need for fluids (there is more on sodium in
Chapter 3
).

10 Minutes Before Start

Taking in carbohydrate within the last hour or so of starting exercise, not including the final 10 minutes before, may cause hypoglycemia (low blood sugar) during the first several minutes of exercise in some people who are especially sensitive to sugar. For them, carbohydrate, especially a high glycemic load source, causes an almost immediate increase in blood insulin levels to reduce the blood’s sugar level, resulting in hypoglycemia.
Many athletes may well experience light-headedness or dizziness in the ensuing exercise because of this reaction. Why doesn’t this happen when high glycemic index carbohydrate is taken in during the final 10 minutes before starting? The answer is that there just isn’t enough time for the body to respond by pumping out insulin. By the time exercise occurs, the body immediately begins to down-regulate its need for insulin. During exercise, sugar intake produces smaller increases of this hormone because the muscles become more sensitive to insulin and permeable to glucose, reducing the need for large amounts of insulin that normally are required to escort the sugar into the muscle.

Taking in 100 to 200 calories from a few ounces of sports drink or gel, followed by 6 to 8 ounces of water, may well give you the energy boost needed right before starting, without any negative effects. This is especially beneficial for those early-morning workouts when you get out of bed within an hour of heading out the door. It may also prove helpful to the athlete who just can’t eat first thing in the morning.

Just as with the preexercise meal examples offered above, the purpose of this 10-minute topping off is to replenish glycogen stores while ensuring adequate hydration levels.

CHAPTER 3

S
TAGE
II: E
ATING
D
URING
E
XERCISE

Eating during exercise is a learned skill that requires considerable planning and testing and includes discovering tasty nutrient sources along with the amounts and timing that work best for you. This demands careful trial and error and meticulous attention to detail. Don’t assume that just because certain sources work well for someone else, they will also work well for you. Tolerance for food during exercise is an individual matter.

FOOD TOLERANCE DURING EXERCISE

The workouts that are the best indicators of what you can or cannot eat are the ones that most closely simulate the event for which you are training, including the expected race duration, intensity, terrain, and weather. You will find that your body’s tolerances for food and fluid change as conditions vary. The least important priority C races on your schedule that mimic the conditions of the priority A events serve as even better tests for nutrition because these also place psychological demands on
you. The ultimate test is the goal race. From this experience, you can draw even better conclusions for future races.

The intensity of exercise has a great deal to do with how well the stomach tolerates food and drink. At very high intensities, such as above 85 percent max VO
₂
(approximately at anaerobic threshold), the gastrointestinal system essentially stops functioning as blood is shunted to the hardworking muscles and to the skin for cooling. Conversely, at low intensities, such as when racing in an ultra-marathon event that takes many hours to complete, many athletes experience an as-yet-unexplained mechanism that produces nausea. Fortunately, if the event for which you are training is short and intense, such as a 5-K run or bicycle criterium, there is no need to take in additional fuel. You have plenty on board already.

If, on the other hand, your event is long and not a steady effort but, rather, punctuated by high-intensity efforts that determine the outcome, such as a bicycle road race, then eating and drinking must occur at times when the intensity is low. The nausea associated with very long events, such as Ironman triathlons or ultra-marathons, isn’t as simple. Among the possible reasons for the queasiness:

Poor pacing.
This is the most common cause of nausea early in a long, steady race. Going too fast in the early stages—perhaps because of nervous energy and a poor pacing strategy while simultaneously taking in food, whether solid or liquid—causes the digestive tract to fill excessively. Due to the high intensity, the gut doesn’t process what’s taken in. Continuing to consume calories even after the intensity has settled at a more conservative level just exacerbates the problem. Slowing down dramatically and temporarily stopping food intake are the only solutions.

Excessive fluids.
Another possible cause of nausea in long-duration events is overdrinking. The stomach can hold roughly 32 ounces and empties at a rate of approximately 30 to 42 ounces per hour, depending on body size and exercise intensity. If the stomach’s reservoir capacity is exceeded, as can be the case with poor race-nutrition planning and a lack of refueling rehearsal, it has no choice but to remove the excess by vomiting.