Pre Game

Marathon nutrition strategy.

The 10K is a great race. It pushes your physical limits, tires you out, and works your heart, lungs, and muscles. But the marathon is an entirely different story. The ordeal of running 26.2 miles draws upon every last nutrient in the human body. It leaves runners as ill-nourished as they are breathless.

A marathon is not healthy for you. It is a good thing to do because it is a personal best and it is a sense of accomplishment, but it definitely tears down your body.

A marathon runner's diet is critical during training to prepare the body for the race. The optimal training diet should consist of 60 percent carbohydrate, 20-30 percent protein, and 10-20 percent fat.

When exercising for under an hour, the only important nutrient for runners is water. You should drink 12 to 16 ounces before running, drink six ounces of water every 15 minutes during the run, and then drink another 12 to 16 ounces afterward.

When training for a marathon, your exercise sessions will often go over an hour, and this is when you must add carbohydrates and sodium to your body during exercise.

CARBOHYDRATES

For energy, your muscles rely on carbohydrates in the form of glycogen stored in your muscles. Exercising for more than an hour can totally deplete your body's store of glycogen. When you run out of carbohydrates you will burn whatever is left. You will burn fat, you will burn protein. That is when you hit the wall and your legs get weak underneath you, and you cannot go any further.

Carbohydrates are mainstays of a marathon runner's diet. You need to consume carbohydrates during exercise in any form possible, depending on the sensitivity your stomach. Some runners can eat trail mix and bananas, but others may find solid food upsetting. Gatorade and GatorLode are just as effective. If you have stomach trouble with sports drinks, you can try diluting them with water.

There is no optimum carbohydrate level that you must consume when running a marathon. Each runner has a different metabolism. You need to see what works best for you by varying the level of carbohydrates you consume while training. To avoid stomachaches during the marathon, find carbohydrates that your stomach can handle while running and stick with the same form throughout training.

FIGHT OR FLIGHT

Marathon runners experience the classic fight-or-flight phenomenon. During the marathon, levels of epinephrine, or adrenaline, increase in the blood. This pumps you up because adrenaline makes glycogen readily available to your muscles. You burn glycogen more efficiently but also deplete your stores quicker, making it essential to have extra carbohydrates available.

The day before long training runs and especially before the marathon, runners should eat pasta to load up on carbohydrates.

SODIUM
Drinking water will replenish your fluid level, but when you sweat you also lose between 2.25 and 3.4 grams of sodium per liter. The cells in your body live in a fluid environment that has a specific balance of sodium and water:

The normal human body has about 140 milli-equivalents of sodium per liter (meq/l, the standard measurement for electrolytes) in the bloodstream.

In order for neurons to send messages and for the cells' basic energy pump to function, your blood's sodium and water levels must be balanced.

Too much or too little of either sodium or water will cause problems.

The major health risk is a sodium deficiency called hyponatremia, a dangerous condition that leads to weakness, nausea, and can cause convulsive spasms. The ATP pump can stop working and the blood cannot deliver enough energy to keep the muscles working. In extreme cases, when sodium levels fall below 120 meq/l, runners can black out, and possibly experience seizures or coma.

Fortunately, athletes rarely sweat long enough to severely deplete their sodium levels. In my experience, even marathon runners, who sweat constantly for three hours, usually finish the race with over 130 meq/l. They feel a little woozy, but are not seriously risking their health.

The best way to avoid losing sodium is to drink it. Sodium tablets are not the answer. Sports drinks like Gatorade are good because they have premixed the right balance of sodium to water. Consuming plenty of sports drinks is the easiest way to avoid fluid imbalances.

FLUIDS

You normally have about six liters of blood circulating through your body. As you lose water through sweat, what really happens is a loss of the fluid in your blood. Constant sweating for over an hour decreases the total amount of blood volume in your body. Your blood "thickens", making it harder to circulate, and your blood pressure drops, causing you to feel dizzy or in severe cases, to faint.

You are losing blood volume, almost as if you are bleeding, when you get dehydrated because the amount of blood you have available to deliver oxygen decreases. When dehydrated, you cannot provide enough oxygen to keep your muscles working. You should be fully hydrated before starting a long run. Clear urine is a sign that you have more than enough water in your system. While running, you should drink a few ounces of fluid every 15 minutes.

Drink before you are thirsty. Once you feel thirsty, you are already dehydrated.

OVERHYDRATION

Normally, a healthy runner with no heart or kidney disease cannot drink too much water," says Bruno, "your kidneys will keep urinating until the excess water is gone."

However, if you run for over an hour, your body shuts down some of the blood vessels in your kidneys. This can sometimes lead to over-hydration if runners drink excessive amounts of plain water during exercise. Water-intoxication can result in weakness, nausea, and muscle spasm similar to having low levels of sodium. Instead of low-sodium, the blood has too much water, and the balance necessary for proper cell function is disrupted.

Water and sodium alone are not the issue. The two nutrients must be in balance for the cells to pump energy and keep a runner on his feet. Simply consuming plenty of sports drinks is the easiest way to avoid fluid imbalances.

PROTEIN
Runners need protein to help build muscles and to recover from training runs. One guide is that recommends that runners multiply their weight by about .7 to get the number of grams of protein they should eat per day. This should work out to be no more than 20 to 30 percent of a runner's diet.

You may not want to go on a high-protein, carbohydrate-free diet while training. These tend to dehydrate a runner, and can cause the kidneys to inefficiently clear fluids.

FAT

Fat is good to cut down. The less you weigh, the less you have to carry around for miles. But zero-fat diets are also bad. You need fat for a number of things. Many of the vitamins in your body are fat-soluble, and if you have no fat you cannot absorb them. Fat also helps with the warming of the body, which is important for marathons in cold weather.

VITAMINS

A balanced diet will provide all the vitamins you need to be a strong runner. You might consider taking a daily multi-vitamin loaded with the anti-oxidants vitamin C and E to protect the heart and blood vessels.

Many health stores claim that chromium supplements aid runners, but no studies have proven the effectiveness of any vitamin supplements.

Vitamins only help if you have a particular deficiency in your diet. For example, women who are anemic can benefit from iron and folic acid supplements. They will be able to improve their marathon times as the levels of iron increase back to normal.

MEDICATIONS

Many prescription drugs affect the levels of sodium in your blood and can be dangerous for marathon runners. Consult a physician before a marathon if you are taking any medications.

Pain relievers, antihistamines, alcohol, diuretics, beta-blockers, and most other medications impair your ability to sweat to some degree. This affects your body's cooling mechanism and can lead to heat exhaustion and fainting during a marathon.

LOSING WEIGHT
Many athletes think they need to drop a few pounds before they can run a marathon. Unfortunately, many of the popular low-carbohydrate, high-protein diets are detrimental to marathon runners. Runners should quit any strict weight-loss programs, which can limit nutrients and create fluid imbalances, at least two months before a marathon and switch to a balanced, high-carbohydrate diet. Marathon training alone is intense enough to burn calories and help you lose weight.

RACE-DAY DIET

Runners should load up on carbohydrates the night before and eat a bagel, some bread, or pancakes the morning before the race. Drink plenty of water and sodium a few hours before the race begins.

Wake up early in the morning and eat as soon as possible, to give your stomach maximum time to digest. Do not eat anything that contains fat, like butter or cream cheese, as fats take longer to digest and could upset your stomach.

During training, you should have already figured out what works best for you, so the only thing to remember is to stick to your plan and do not try anything new right before the race.

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