Fueling Your Marathon

Eating and Drinking before and after your Marathon

By Nanna L. Meyer, PhD, RD

Research Associate & Sports Dietitian Office- 801.314.4038 Fax- 801.314.4862 

Eating the morning before your marathon: Eating your breakfast before a marathon is key to fuel up and charge your batteries after a nights sleep and before hitting the starting line. However, you have to do it early. This means that you should probably get up to eat and go back to bed because it is unlikely that the food you eat 1-2 hours before the start will do you any good.  You should get into the habit of eating about 3-5 hours before the race start. Your meal should be high in carbohydrate, very low in fat, and have some protein (see below for options). Whether you eat shortly before the start is you own choice. The fuel you are getting will not spare what you have stored in the muscle, and thus, it seems unnecessary, especially is you have access to sport drinks, gels, and bars during the marathon. You should however drink a couple of cups of fluid before the start. If you prefer drink a sport drink.

 Most important is that you trial and error your strategies in training to identify what your body needs to maximize energy stores, without compromising feeling well and light for the race.

 Examples of Breakfast for Marathon Running: (target about 0.5-2g per lb of body weight)

• Bowl of Oatmeal with brown sugar and cinnamon; 1 cup skim milk; 1 cup apple sauce; Luna Bar
• 1 Large bagel; banana; honey or jam with little butter or Earth Balance Spread; 1 cup yogurt or skim milk; power bar
• Bowl of Cereal; banana; skim milk; toast with Earth Balance Spread; jam; power bar
• 3-4 medium size pancakes; maple syrup; 1 cup apple sauce; yogurt or skim milk; Luna Bar
• Bowl of creamed white rice or couscous(with skim milk); cinnamon; brown sugar; banana or apple sauce; Clifbar

 Have plenty of water or sport drink 2-3 cups

 Fueling during Running: There are several things you should consider regarding the optimal fueling strategy during your marathon. You will need water, electrolytes, and carbohydrates. Lately, the importance of protein has also been discussed; however, whether you take in protein probably depends on how long it take you to complete the Marathon and how sore you usually get from running a marathon.  Protein might alleviate some of this post- marathon muscle soreness.

 Hydration and Electrolytes: Sweat rates in marathons vary a great deal and are between 500 ml to 2.5 L per hour. The fact is that you should measure your own sweat rate, by weighing yourself before and after running in a similar environment condition in which you expect your marathon to be (see below for calculation of your sweat rate). General guidelines through the USA Track and Field are to drink around 300-500 ml/h. newly, it has been established that drinking in response to thirst is actually a good idea.  In fact, research has shown that some marathoners over drink and gain weight. This is as dangerous as not drinking enough, and can lead to the dilution of blood serum sodium levels, also called hyponatremia. Thus, it is now recommended that you do drink according to your sweat rate and even using your thirst as a good indicator to drink. If you fain weight during a marathon it is NOT normal and is probably due to the fact that you drank too much!

 Measuring Sweat Rate

Pre-Workout Weight:                           73.5 kg                        162 lb

Post-Workout weight:                           72.5 kg                        159.8 lb

Amount of fluid consumed during          0.5 l water                    32 fl oz

Work out Duration                               1.5 hour

 Conversions:

1kg water = 1l water

1kg = 2.2 lbs

1l = 32 oz

 Sweat Rate:

Step 1: Determine amount of weight lost during workout (fluid deficit): 73.5-72.5=1 kg (1 l fluid)

Step 2: To this, add the amount of fluid consumed during workout (total sweat loss): 1 l + 0.5 l = 1.5l

Step 3: Determine sweat rate by dividing the total sweat lost by the duration of the workout: 1.5 l/ 1.5 h = 1 l/hour

 (Australian Institute of Sport: http://www.ais.org.au/nutrition/documents/FactSweat.pdf )

 Proper Weighing Techniques: it is preferable to get a nude weight for precise results. If this is not possible, a weight in the same clothes pre and post workout with no shoes is acceptable

 In example above, the goal would be to consume between 750 ml and 1000 ml (24-32oz) of fluid per hour in order to properly replenish fluid losses and maintain physical performance during exercise. A decrease in body weight of 2% or more due to fluid loss can lead to significant decline in performance. In the case above, this would be a loss of approximately 1.5 kg (3.3 lbs).  In our example, 1.3% of body weight was lost in this 1.5- hour exercise.

 What about electrolytes? Typically, sport drinks contain between 150-200mg of sodium per 250 ml (8 fl oz).  The lower amount is probably enough to replace your sodium in a temperate environment. In the heat however, it is smart to choose a sport drink that has a higher level of sodium such as Gatorade Endurance.

 Carbohydrates: The amount of fuel you can burn by your muscle during exercise is limited.  In fact, the muscle oxidizes about 1 g of carbohydrate per minute. This means that there is no need to consume more than 60 g of carbohydrate per hour.  Most sport drinks contain around 60 g of carbohydrates per liter (32 oz) in the form of glucose, fructose, sucrose, and maltodextrin.  Depending on your sweat rate and drinking habit, you may get the top amount of Carbohydrates from your sport dink without having to rely on any other fuel source from a bar, gel, jelly beans, or Clifbloks. However, if your sweat rate is much below 1 liter (32 oz) per hour you will end up drinking less and may profit from extra carbohydrates. Again, key is that you try these things out in training and decide what sits best in your stomach and feels like a quick fuel to your muscle.

 Protein: Lately, more attention has been given to the addition of protein in a sport drink.  Research has shown that protein may help carbohydrate delivery, delay muscle damage and help with recovery, and promote hydration. Whether or not you chose a drink with protein depends on your preference. The amount of protein consumed per hour remains fairly low (5 g/hr) and you can obtain it in the form of sport drink or a get (Acclerade; Accelgel). Make sure you try these strategies before using them in a marathon.

 Caffeine: If you want to boost your performance just a bit more, after you have taken care of the essentials (Fluid, electrolytes, carbohydrates, and possible protein), consider using caffeine. Caffeine can conveniently be consumed in the form of a gel or caffeine tablet. Latest research shows that caffeines performance enhancing effect is through your central nervous system, enhancing your motivation, focus, and perhaps pain tolerance. To good news is that you dont need much caffeine to profit from this performance boost and you can choose to consume it either early or late in the marathon.  It takes about 15 minutes for caffeine to do its trick and the effect is long lasting, up to 6 hours. Recommended amounts are small (3 mg/kg of body weight), although smaller amounts may also work. Watch out for caffeine tablets! They have a much higher content and can leave you jittery and anxious! Thus, caffeine in gel form is probably a better idea.  Important to understand is also that caffeine during exercise is NOT a diuretic, and thus, you should not be concerned with fluid loss due to caffeine.

 Recovering after Running: Once your race is over, the painful memories of muscle damage and soreness will follow.  You are doing best in rehydrating immediately with a sport drink and eating a couple of bananas, some pretzels, and a yogurt or some milk.  The recovery mix should contain fluid, electrolytes (sodium/potassium), carbohydrates and proteins should be consumed immediately after you race. Follow through with continued recovery to speed up muscle repair, glycogen repletion, and rehydration. This means that you should eat a nice meal about 1-2 hours after your immediate recovery snack. The meal can be a bit higher in fat such as a nice Mediterranean lunch with a colorful salad with olive oil, followed by pasta with tomato sauce and grilled salmon, and a dessert.  Recovery through fueling can and should be prolonged over the course of about 4 hours. So, continue eating small snacks combining carbohydrate, protein, healthy fats (nuts, seeds, olive oil, avocado, fish, and fluid and enjoy that you mastered an enormous physical challenge!