The Best Diet for Marathon Training: What to Eat Before, During, and After Runs 

Is there a majestic, perfect diet for marathon runners that everyone should follow? In short, no.  

Just like every diet from Paleo to vegan you have to find which one you can stick with and ones that are not too restrictive on a proper balance of carbohydrates, fats, and proteins. Whether you are trying to PR or simply trying to lose weight, there are some universal rules that can be modified to fit within each diet. 

If you are looking for the best diet to lose weight for running or to maximize your marathon training plan, it involves a mind shift from thinking only of calorie counting to focusing on fueling and recovering properly before, during and after your runs. 

Once you have this mindset down, your running will start to improve as your nutrition improves. Not to mention, you will feel better and begin to see those pesky pounds start to shed when you are fueling and recovering the right way. 

What To Eat Before Your Runs  

Carbs. 

They get a bad rap. However, running relies on utilizing energy from glycogen stores in the body which are fueled by eating carbohydrates, thus the term “carbo-loading.” 

Carbo-loading before races or training runs is common because it fills this glycogen store in the muscles and provides the energy necessary to exercise. However, it does not mean that runners are scarfing down large pizzas before the race. They are simply incorporating more “good” carbohydrates into their diet following up to the run. 

Similarly, before your training runs, you want to be sure you have had some form of carbohydrates either the night before or for breakfast, or both. 

So, what are “good” carbs? Good carbs are vegetables, whole fruits, legumes (lentils, beans, etc.), nuts, seeds, whole grains and tubers (potatoes, yams, etc.). Here are some examples of what to eat to fuel up for a run in the morning (or whenever) that are carb-heavy:

•    Whole grain cereal with a banana 
•    Whole wheat toast with nut butter and berries 
•    Oatmeal with pumpkin seeds, brown sugar, and apple
•    Steel cut oats with pears and cinnamon 
•    Energy bar and an apple 
•    English muffin with egg and spinach
•    Whole grain waffle with yogurt and strawberries 
•    Sweet potato hash and a side of fruit
•    Whole wheat toast with bananas, chia seed, honey 
•    Whole grain crackers and hummus 

Any of these can be modified to fit your diet. For example, cereal with milk can be replaced with almond milk for vegan diets. Bread can be replaced with Paleo bread for Paleo diets and so on. 

These are also foods that are relatively easy to digest and provide energy roughly one hour before your run. One of the key tips is to try not to overeat, especially before your run. All of these should be thought of in terms of one serving. Eating in excess can make for a very uncomfortable run, causing cramping, nausea, or bloating. 

Water is also important, as it always is in any diet. Ensure you are taking in at least 90 ounces for women and 125 for men. This is slightly higher than average due to what you will sweat out during your run.  Hydrating before will also aid in the digestion of these pre-run fuel foods. 

Lastly, not eating anything before a run can cause “bonking.” This is a common runner term to mean your glycerin stores have been fully depleted and you lose energy on your run. Runners report feeling very fatigued, shaky, have chills, and cramping during a “bonking” episode.  If this happens, it can be especially nice to have something with you on your run to be sure you can refuel and continue.

What To Eat During Your Run 

More carbs. 

But eating during a run can be tricky. Much of it is trial and error to figure out what works best for you (and your stomach).  But first, how do you know when to even eat during a run or if you need to eat during a run? 

The rule of thumb is usually over an hour. Alternatively, if you are more experienced, you can ensure you are fueled up before a run and go for two hours without needing extra calories.   

Another way to go about this is to play it by ear. Carry what you need on you and take in a little as soon as you feel you may become fatigued. There is no need to overeat on a run if you feel you have the energy to sustain your run, especially if shorter. 

However, running over an hour, we burn anywhere from 400-700 calories per hour, which for most of us means we can replace some of that to sustain energy.  You can choose to do this a variety of ways: through solid food, gels, or sports drinks designed to pack in calories specifically for running. Here are some examples of high-carbohydrate, digestible supplements and food to try out:

•    GU Energy Gels Gels 
•    Hammer Gel 
•    Honey Stinger Gels 
•    GU Chomps
•    CLIF Shots
•    Honey Stinger Energy Chews 
•    Gatorade Endurance 
•    GU Brew 
•    Tailwind Endurance Fuel 
•    Honey Stinger Waffles 
•    Gummy Bears 
•    Cliff Bars
•    Jelly Beans
•    Peanut Butter Jelly Sandwiches (small pieces)
•    Pretzels
•    M & M’s 
•    Small boiled potatoes 
•    Banana

A big tip during-run fuel is to be sure to experiment with what works for you during training runs and NOT during race day. As many runners will say, “nothing new on race day.” You don’t want to run a race in shoes you haven’t yet tried, so the same goes for nutrition. 

What To Eat After Your Run

Protein. And fats. And more carbs. 

One of the most important yet missed parts of training is recovering with food. If given proper deliberation, you can truly feel the difference on your runs.  Running, like all other workouts, tears down muscle, which is why it is essential and advantageous to recover as best as possible with the best food possible. This, in turn, shortens the recovery time and makes your body heal quickly to keep your legs feeling fresh for your next run.

The great thing is there are foods that actually reduce inflammation and speed recovery. Whether it is in the form a smoothie or solid foods – or both – be sure to incorporate some (or all) of the below foods into your diet.

•    Almonds
•    Eggs
•    Black beans
•    Yogurt 
•    Salmon 
•    Whole grain pasta
•    Lean meat such as chicken or salmon
•    Mixed greens
•    Beetroot
•    Ginger
•    Spinach 
•    Broccoli
•    Berries (such as blueberries, strawberries, raspberries, etc.)
•    Oranges 
•    Dark Chocolate 
•    Sweet potatoes
•    Avocado 
•    Seeds (Chia, Sunflower, etc.)

This list includes proteins, fats, and carbohydrates – but all are healthy forms of those. It is best to avoid too much red meat, processed foods, sugar, alcohol, and fried foods, which are high in saturated fat and can make inflammation worse in the body. 

Additionally, eat fairly soon (about within the hour) after your run. This will maximize the absorption of nutrients to the bloodstream and muscles. A good tip is to carry a bar (such as a kind bar) in your car so that you can eat it on the way home from a run. 

What If I’m Still Not Losing Weight?

So, after all of these lists, why is it that some runners still do not lose weight despite logging a ton of extra miles? Many times it is portion control, which plays into the said importance of recovery. Due to the major increase in physical exertion, many find themselves, for lack of a better word, starving after their workouts. This causes them to eat more than they intend to and either end up maintaining their weight or gaining some.

The way to ensure running is burning calories and that you aren’t piling them back on is to make sure you are burning more calories than you are putting back in. MyFitnessPal (app or website) is a great way to log your workouts and track your caloric intake. This will tell you if you are adding, breaking even, or in a calorie deficit after logging workouts in the app.  To lose weight, you want to be in a calorie deficit which means you are burning more (calories spent throughout the day) than you are taking in (calories in food).

Secondly, as discussed it is important to recover quickly with the above foods. A smoothie with fruit and protein powder can also help recovery and curb your appetite.   

Finally, make sure you are not increasing your mileage over 10% each week. Too much strain on the body will live you fatigued, injury prone and very hungry which may cause overeating.  

So in summary, watch your calories, recover with food, and ease into your weekly mileage.

But after all of this is said and done, the most important thing is NOT GIVE UP! It can take a time to train the brain and the body to not only accomplish the distance of a marathon but to continually make good food choices. The important thing is to keep going when the going gets tough. Isn’t that the runner spirit?