What to eat the week before the Boston Marathon

Posted on 12-04-2016 , by: Nancy Clark , in , 0 Comments

Your training may be done, but your can still enhance your performance by eating wisely, Here are answers to some questions you might have about how to eat the week before the marathon.

Question: I’m getting nervous about what to eat the week before the Boston Marathon, as well as what to eat on race day. Should I be carb-loading or doing something different???

Answer: Many runners believe they should eat a special diet the week before the marathon. The truth is, your training diet should be similar to your pre-marathon diet. After all, how can you train at your best if you don’t fuel at your best? If you failed to consume adequate carbohydrates, protein, fat, and fluids on a daily basis, your training suffered, and this means your marathon will suffer.

The biggest changes pre-marathon should not be in your diet but in your training. Be sure to taper off your training during the week prior to the marathon. This allows your muscles adequate time to:

1) fully load-up on carbohydrates (called muscle glycogen)

2) replace depleted fat store within the muscle (beneficial source of fuel), and

3) heal the tiny injuries that occur during hard training, so you’ll start off the marathon in optimal condition.

Question: How can I tell if I’ve eaten enough carbohydrates?

 Answer: You won’t feel hungry! Your body is your best calorie and carbohydrate counter. Once your muscles are “carb loaded”, your appetite will drop. Because muscles can need up to two days to fully refuel, you can be just as hungry on rest days as on training days.

If you see the scale going up, fear not. For each ounce of glycogen stored in your muscles, you’ll store about three ounces of water. Some runners gain two to four pounds of water weight; the water will become a helpful source of fluid during the marathon. They have not “gotten fat” but rather are well fueled.


Question: Does it matter what kinds of carbohydrates I eat to fuel my muscles?

Answer: Carbohydrates are found in breads, cereals, pasta, fruits, juices, vegetables, and sugary foods. Clearly, your overall health will benefit from the wholesome goodness in fruits, vegetables, and whole grains; hence these foods are nutritionally preferable to sugary soft drinks, sports drinks, gels, candy and other sweets. But, never the less, both sugars and starches get stored equally well in your muscles.

When choosing carbohydrates, be sure to choose correctly so you will carbo-load, not fat-load. That is, enjoy generous portions of–

  • pasta with tomato (not Alfredo) sauce
  • thick crust pizza with vegetable (not pepperoni) toppings
  • frozen yogurt (not gourmet ice cream)
  • bread or bagels with jam and only a little butter or cream cheese.

Note: you can and should eat a little fat to replace the depleted fat stores within your muscles. You need not “fat load”, but you also need not avoid fat like the plague.

Question: What’s the right balance of carbohydrates, protein, and fat for a marathon runner?

Answer: Each meal should be based on carbohydrates, with protein-rich foods as the accompaniment; add a little (preferably healthful) fat for flavor and satiety. Your meals might look like this:

                        Breakfast                               Lunch                                     Dinner

Carb               Cereal, banana, OJ               Bread, fruit                            Pasta, sauce, bread

Protein           Milk                                        Turkey                                   Ground turkey

Fat                  Slivered almonds                 Cheese, Avocado                 Olive Oil


If you are mathematically minded, the target sports diet for a day of training breaks down like this:

  • about 3 to 5 grams of carbohydrate per pound of body weight)
  • about 0.7 grams protein/lb of body weight)
  • about 0.5 grams fat/lb body weight, or the balance of the calories).

Example: If you weigh 150 pounds and are training about 8 miles per day, you may need about 3,000 calories per day to support your training. You could appropriately target:

450+ grams of carbohydrates per day

105 grams of protein

75 grams of fat

for a total of about 3,000 calories.

When tapering, you need fewer calories. Once your muscles are fully glycogen loaded, your appetite will drop. Eat adequately; don’t skimp — but no need to stuff yourself to the point of discomfort.


Question: What should I eat on Marathon Morning?

 Answer: On marathon morning, be sure to eat breakfast…and you’ll also have time for lunch! Because the BAA Boston Marathon doesn’t start until between 10:00 or 10:40, and you’ll likely be awake at 5 am, you have plenty of time to eat breakfast at 6:00 am and a snack around 9:00 to 10:00 am. Be sure to eat enough fuel on marathon morning to maintain your normal blood sugar level. If you fail to eat enough, your blood sugar will drop, and you’ll suffer from needless fatigue associated with low blood sugar.

By eating about 400 to 600+ calories as tolerated of tried-and-true training food at breakfast and then again within an hour or two before the race, you’ll be better fueled for the 26.2 mile adventure. During your training, you should have experimented with marathon day eating. That is, you hopefully did a few long training runs that started at 10:30, and learned what breakfast and lunch foods settled well–and how much your body could tolerate.

Question: What about fluids on Marathon Day?

Answer:   Be sure to drink extra fluids (water, juice, sports drink) up until two hours before the marathon. Your kidneys need about 90 minutes to process fluid; you’ll then have time to urinate the excess. Tank up again 10 to 15 minutes before the start of the marathon.

During the race, prevent dehydration and hypoglycemia (low blood sugar) by drinking 6 to 8 ounces of sports drink every 15 to 20 minutes. Because sports drinks contain carbohydrates (sugar) that fuel both the muscles and the mind, they’ll invest in greater stamina and endurance. If sports drinks upset your stomach, drink plain water and nibble on energy bars, hard candies, jellybeans or other carbs that you can tuck into a pocket. Make sure you’ve practiced drinking sports drinks during your training, so your stomach is familiar with them and you know they settle well.

The bottom line

By eating wisely and well, you’ll be able to rule out your pre-marathon concerns about running out of fuel and “hitting the wall” during a marathon. Have fun running smoothly with good nutrition!


Sports nutritionist Nancy Clark MS RD is author of Nancy Clark’s Sports Nutrition Guidebook and her Food Guide for Marathoners: Tips for Everyday Champions. Both books are handy resources for hungry runners. They are available at www.nancyclarkrd.com. Nancy counsels runners and other active people at her private practice in Newton Highlands. Visit her web site (www.nancyclarkrd.com) for more details.

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