Fueling Your Half Marathon or Marathon

Training for a half-marathon or marathon requires a lot of time and hard work. We are asking our bodies to perform at a high level, day after day, month after month. To support our body for all this work, we need to give it the fuel it needs when it needs it. During a half-marathon or marathon training cycle, we focus on three areas of nutrition: daily nutrition, performance nutrition, and recovery nutrition. If we nail our nutrition in these essential areas, we will best support our bodies as we put in the miles during training.

Daily Nutrition

Daily nutrition is the foundation of our fueling. All athletes need to consume three balanced meals per day. A balanced meal includes carbohydrates, protein, healthy fat, and color from fruits and vegetables. We want to ensure we consume adequate protein at each meal to maintain and build lean muscle mass and do not skimp on carbohydrates. Carbohydrates are the most efficient fuel source for our muscles and brains. To consume adequate nutrition to support both performance and recovery, we need to be eating every three to four hours. Snacks can be helpful to fill in the gaps between meals.

Performance Nutrition

Performance nutrition is the fuel we give our bodies to support running performance. This means consuming carbohydrates, fluids, and electrolytes prior to and during all exercises in our training block.

Before heading out for a run, aim to consume at least 25 grams of carbohydrates for runs <70 minutes, and at least 50-60 grams of carbohydrates before runs >70 minutes. If you have less than 60 minutes until your run, simple carbohydrates that are low in fat & fiber are best, such as a banana, toast, cereal or graham crackers. If you have 1-2 hours before you are out the door, you may be able to tolerate some fat and fiber in your pre-run snack, such as toast with peanut butter or Skratch Energy Bars. Carbohydrate needs pre-run may vary depending on the size and experience of the runner and when the runner last ate.

Athletes need 30 - 90 grams of carbohydrates per hour while running. Carbohydrate needs during running vary depending on the intensity of the run, the athlete's experience, size, and gastrointestinal tolerance of fuel sources. During the run it is best to spread out the consumption of fuel to every 20 to 30 minutes. Fast, easy-to-digest sources of fuel are best while running. Skratch Energy Chews or Skratch Super High-Carb Drink Mix are great options for carbohydrates on the run.

Hydration also plays an essential role in performance. When we get dehydrated, we can experience GI distress, muscle cramps, dizziness, fainting, increased perceived exertion, and decreased performance. Hydration is highly variable from individual to individual. The average runner needs to aim for 8 - 16 oz fluid per hour and 200 - 600 mg sodium per hour. If you have a low sweat rate, you may need to scale down; if you are a heavy and/or salty sweater, you will need to scale up. Skratch Hydration Sport Drink Mix is the perfect drink during exercise - with electrolytes and a bonus of extra carbs. If you are a saltier sweater, try adding the Skratch Everyday Drink Mix to the Sport Drink Mix to increase sodium per bottle. Check out my sweat rate and sodium calculators to better fine-tune your hydration during training and race day.

We want to practice our race-day fueling and hydration strategy during our long runs, so we support our performance in training to gain more fitness, train our GI tract to tolerate our during-run fuel, and execute it well on race day.

Recovery Nutrition

Proper nutrition after running allows our bodies to recover, heal, and prepare for the next training session. Post-exercise protein helps to repair and rebuild our muscles, and post-exercise carbohydrates replenish our glycogen stores. Adequate glycogen stores give us energy during endurance feats and help with muscle contractions. Most runners will need 20 - 40 grams of protein and 50+ grams of carbohydrates for recovery. Recovery nutrition needs vary based on age, training, goals, and athlete’s biometrics like height and weight. Timing of recovery nutrition is also important. To maximize recovery, aim to get your protein in within 30-60 minutes and carbohydrates within 90 minutes post-exercise. If you are unable to consume your recovery meal shortly after your run, a great place to start is with Skratch Recovery Sport Drink Mix which contains a 4:1 carb-to-protein ratio to jumpstart recovery post-run, and then follow up with the rest of your meal within 60 minutes. Check out your individual needs on my recovery calculator.

Fueling Up For Race Day

An essential part of getting ready for race day is the Carb Load. Carb loading involves intentionally increasing carbohydrate intake for 1 - 3 days pre-race to stock glycogen stores for race day. Proper carb loading before an endurance event over 90 minutes has been shown to improve performance by anywhere from 2-3% (PMID 9291549). You will also need to increase your water intake on carb-loading days, as glycogen is made up of water + glucose. Carb loading can feel daunting to some athletes, but it doesn’t need to be. Here are some of my tips for carb loading: plan it out (use my free carb load guide & carb load calculator), drink some of your carbs, and stick with easy-to-digest carbohydrates sources such as pretzels, white bread, juice, candy, white rice, Skratch Energy Chews, Skratch Super High Carb Drink Mix, and Skratch Hydration Sport Drink Mix. Avoid high fiber & high-fat carbohydrates - you won’t feel as full.

Before Your Race

Depending on the start of your race, you will want to eat carb-heavy foods 1-2 times pre-race and give yourself plenty of time to digest your food. An excellent place to start is to take your weight in pounds and divide that by two (or use your exact kilograms if that is the unit of weight that you are used to using) - that is the amount of carbohydrates you need to consume approximately 2 hours before your race. For a late start race (10 am or later), consume that amount of carbs at 4 hours before and 2 hours before your race. You will also want to drink 8 - 16 oz of an electrolyte drink and try to finish it 1 hour before the race to minimize bathroom stops. For an early start race (7 am or earlier), you can eat once or twice pre-race, depending on your preference.

During Your Race

Before any race, I tell my clients to take Skratch Energy Chews or a gel 5 - 10 minutes before the start. This will provide fast energy right off the bat and ready-to-burn fuel. For race-effort half and full marathons, I recommend fueling with 25 - 30g carbs every 30 minutes at a minimum. Research has shown that athletes benefit from 50g carb/hr for endurance efforts >2 hours For longer or higher intensity efforts, you may benefit from up to 90g carb/hr (PMID 24791914). Practice this in training so you know your sweet spot for race day. Don’t forget about your hydration while you’re out there! Taking adequate fluid & sodium, such as Skratch Hydration Sport Drink Mix, is key to avoiding the negative side effects of dehydration, such as stomach sloshing, nausea, diarrhea, cramps, etc. During an endurance event, the average athlete will need 8-16 oz/hr for fluid and 400mg sodium/hr. However, fluid and sodium needs can vary greatly, so please consult your sports dietitian to help determine your specific needs.
There are an array of factors that can determine your absorption rate - most of my athletes sit comfortably between 45g -120g of mixed carbohydrates. Based on what is easier for you here is a good starting point - we usually start with 5 scoops per 20oz bottle (if you use a bottle per hour) or you can spread out 7 scoops over 1.5 hours if you are wanting to reduce the amount of bottles you are using (this may depend on the temperature you are training in if you need more water or less).

If you are experiencing GI distress, use less scoops. If you are tolerating and want to experiment (maybe for the longer race) you can add more scoops per hour to see if you can absorb more CHO for longer lasting performance and better energy. If you are mixing with the Sport Hydration mix make sure to count the carbs from that into your total carb math and what your personal needs can consume per hour.

About the Author

For more information from sports dietitian Meghann Featherstun, visit her website at featherstonenutrition.com or Instagram.

For the last 15 years, I have been working to help clients find their happy place with nutrition, exercise, body composition, and life. For the last 8 years, I have been a Certified Specialist in Sports Dietetics (CSSD), aka a Sports Dietitian, helping runners and endurance athletes fuel their biggest, baddest goals. Specializing in sports performance nutrition while having a heavy background in clinical nutrition to help athletes also manage their medical conditions and/or understand their own health history and lab work. I help my athletes find their own balance between nutrition, life, and fitness goals. No two stories are the same. Therefore, no two nutrition plans are the same. Each athlete is a unique individual who needs a specialized plan, tailored to them.