Marathon, triathlon and endurance training in general, is one of the fastest growing sports segment in the world. A marathon serves as a personal achievement without need for a competition with another person. You are truly competing against yourself and that PR you hit, says that about what you made yourself do, despite the odds!

However, for the first timers, running a marathon or even a half-marathon can be a daunting task. Unless you have a group that works out with a half-marathon training plan or a defined program, doing it purely by yourself may not be that easy.

After training, fueling for a half-marathon is probably the most important task. Proper fuel the day before, the day of and the day after your half-marathon will determine not just how you do that day, but also how quickly you recover. 

There is a lot of debate about how and what to eat to be able to run a half-marathon. While meal plans can be determined by individual tastes, the fundamentals of eating the right amount of calories, and getting your macros right, is a universal paradigm.

A few suggestions have been outlined below for guidance.

FUELING BEFORE HALF-MARATHON

The thing to remember is that even though the race is on one particular day, the preparation for it takes many weeks. And the day prior to the half-marathon is the day you absolutely want to get the fuel right.

In fact, it is said that fueling prior to the half-marathon (at least a week in advance) is more important than the day of the actual race. This is because the source of calories, macronutrients and micronutrients (including minerals and electrolytes), all determine how you will eventually perform the day of the race.

Nutritional deficiencies, particularly of minerals such as magnesium can build over a period of time. They also take time to correct. A nutritionally depleted body cannot perform the day of the marathon despite the best meal or hydration on that particular day.

So, proper fueling for the half-marathon should start at least a week before the race. Eat healthy, eat a mix of protein, vegetables and cut out all the junk. Supplement this with electrolyte-based hydration a week before, because just like nutrients, hydration also should improve on a daily basis.

WHAT TO EAT THE DAY PRIOR TO HALF-MARATHON

The advice that is most commonly given is that a balanced meal, easy to digest, rich in carbohydrates, protein and fiber is probably the best pre-marathon fuel. 

Our favorite thing on the menu is a turkey or an egg sandwich on a wheat bread with plenty of greens and avocados. Of course, one can substitute meat for a vegetarian patty and add vegetables to one’s taste. Being rich in protein and carbohydrates this week cannot go wrong. There are many athletes who eat the same food all week before a marathon “just to get it right”.

The idea is that your pre-marathon meal plan should have enough calories coming from mixed sources of macronutrients- protein, carbohydrates and fat. The meal should also be rich in electrolytes including sodium, magnesium and potassium. 

A side of apples, bananas or freshly squeezed orange juice can significantly help electrolyte intake which is key to building your electrolyte levels up prior to the marathon.

HOW TO FUEL THE DAY OF HALF-MARATHON

As expected, fueling during the day of the race is critical. In the morning of the race, the first meal in the morning should be kept light but should have enough calories to sustain yourself at least for an hour (or 45-60 minutes).

A carb rich meal in this context is a decent idea. Some examples include a bagel with cheese and jelly, peanut butter sandwich, egg white sandwich, etc. Carbohydrates during the race are the easiest source of energy. Avoiding a protein rich meal as fuel prior to the half-marathon race has its advantages because protein takes longer to digest and it is harder for your body to use amino acids quickly for energy than carbohydrates.

Normally, muscles and liver contain enough glycogen (about 1800-2200 calories worth of) to last your race but as glycogen gets depleted and after about 60 minutes of continuous activity, some refueling is needed. 

During the race, easy on-the-go eatables such as bananas, graham crackers, jelly beans, sugar blocks are excellent sources of fuel. Some carbohydrate rich gels are also good choices since they can be easily absorbed from the gut.

The key to your pre-marathon fuel is that you should not overeat prior to your race. This is why hydration (see next section) is the key additive to your fuel during a half-marathon.

FUELING YOUR HALF-MARATHON SHOULD INCLUDE PROPER HYDRATION 

During the race, you do not have the time to sit and eat. Hence, fueling must be done on the go—this is where electrolyte drinks are the best fuel for an endurance event like a half-marathon.

Ideally, electrolyte infused drinks should have some sugar as an instant source unless you want to take it separately (not recommended). Sugar free drinks do not sustain a marathon endurance run. 

Some athletes use about 10-15 g of carbs per 45-50 minutes of activity. If used correctly with the right blend of electrolytes, that amount can be cut down (for those who are sugar conscious). Hydration is not just a source of water but also for some nutrition as well as electrolytes. 

But not all electrolyte hydration packs are good fuels for a half marathon. Those that are too rich in sugar are difficult to absorb from the gut. 

Ideally, the sugar in the electrolyte drink should not be > 10 grams per 12 fl. oz of water, to keep the osmolality of the solution low. As dehydration ensues, the higher osmolality in the blood allows the water and electrolytes to be absorbed from the stomach faster. A very high sugar content (>20 grams /8 fl. oz as in common sports drinks) prevents this and leads to nausea.

Your electrolyte drink should be rich in magnesium, potassium and have a balanced amount of sodium (at least 200 mg or 400 mg of sodium chloride) since sodium is the principal electrolyte lost in sweat. Sodium deficits in some marathon runners may be up to 1-1.5 grams per race, but the replenishment can be gradual, during the race and during the recovery.

HOW TO HYDRATE DURING YOUR HALF-MARATHON

Remember, your fuel during a half-marathon is more dependent on electrolyte-based hydration than your pre-marathon meal. Drinking enough liquids allows blood volume to be maintained and electrolyte balance to be proper. It also prevents cramping, low blood pressure and overt dehydration.

But drinking plain water is not recommended during a marathon (or generally, if the activity is strenuous and lasts more than 30-40 minutes). This is because as the body is dehydrated, vasopressin (or anti-diuretic hormone) released from the brain causes water retention. If an athlete ingests pure water without electrolytes such as sodium, hyponatremia (low blood sodium) can develop; and it is seen in up to 20% of endurance athletes.

Drinking 8-10 fl. oz of electrolyte water such as MAGNAK®, every 20 minutes of activity/running at a moderate pace is the minimum that we recommend. If it is hot or you tend to sweat more, a higher rate may be needed. One should aim to at least consume 16 fl. oz or roughly half a liter of liquid per 30-40 minutes of activity in this setting.

Magnesium allows potassium to be retained in the body and muscles to contract efficiently without cramping. Sodium and water allow blood perfusion to be maintained. Supplement that with some calories from simple sugars, and you have the right fuel to ensure you hit a PR on your next half-marathon.

Learn why MAGNAK® is the best fuel for your half-marathon.