12 Science-Backed Nutrition Tips for Runners and Triathletes

Male triathlete displaying intense focus and impressive endurance while swimming, thanks to a well-balanced marathon nutrition diet

The nutritional needs of runners and triathletes are unique. When you are logging dozens of miles a week, your body requires fuel that replenishes energy and supports the strengthening of your muscles, bones, tendons, and other tissues. Equal attention to both your training regimen and your diet is required for maximum progress and performance. Nutrition for runners focuses on whole foods rich in carbohydrates, protein, fats, as well as a plethora of vitamins and minerals. 

Looking for ways to improve your diet as a runner or triathlete? Are you preparing for a marathon or half-marathon? We’ve compiled evidence-based tips specific to your needs as a high-performance individual. 

#1 Nutrition for Runners & Triathletes: Calculate Your Specific Calorie Needs

It may seem basic, but in order to feel your best and achieve the results you want, you need to know your daily calorie needs. There are several things to take into consideration, including the time you spend training every day, your Base Metabolic Rate (BMR), your balance of macronutrients, and how you FEEL about how much you’re eating. 

Some basic guidelines are as follows: 

  • For Men50 kcal/kg/day + additional intake to compensate for miles/resistance training 
  • For Women45 kcal/kg fat-free mass + additional intake to compensate for miles/resistance training 

Important note for female athletes: Researchers have noted that female athletes tend to have lower energy intake than their male counterparts, which may lead to nutritional imbalances and deficiencies. This is likely due to cultural expectations and underestimated calorie needs. Women should take extra care to get the amount of food they need to stay strong, healthy, and nutritionally balanced. 

No two runners are alike, and you should experiment to find your “sweet spot” with daily food intake. Nutrition for runners and marathon runners should be personalized to each individual.   

#2 Fuel Up Before Your Race or Training

Eating about 30-120 minutes before a run will ensure you have good energy for your workout, and also help to prevent hunger pangs later on during the day. Exactly when you eat is something you need to figure out for yourself. Some runners like to eat within 30 minutes of a run, and others need a solid hour or two after eating before they feel ready to hit the road. In general, the more difficult your run, the more time you should put between your pre-run snack and your workout, to avoid stomach upset. 

You want to eat mostly carbs, as these will digest easily and provide a quick energy source for your muscles. Fats, fiber, and heavier foods take too long to digest and may lead to digestive upset or sluggishness during your run. 

Along with carbs, collagen is a great protein to ingest pre-workout. The amino acids will peak in your body around 60 minutes, so consuming a collagen protein shot 15-30 minutes before you exercise is ideal. 

Some good pre-workout choices may include:

  • Banana
  • Almond butter 
  • Oatmeal
  • Honey stick 
  • Toast with peanut butter and jam
  • Berries 

Experiment with your snacks to see which ones help you feel the best during a run. When you are heading into a race or event, however, stick to ones you know work well for you. It may take some trial-and-error, but in time you will find your “go-to” snacks and meals that help to fuel your runs and give you optimum nutrition. For runners, quality is the most important thing to focus on when choosing your food. 

#3 Drink The Right Fluids 

Depending on the length and difficulty of your run, you want to make sure you’re drinking the right fluids. For runs shorter than 60 minutes in a mild environment, water should suffice. Once you bump over 60 minutes, or if you are doing a run in hot weather, you want to add fluids that contain electrolytes. Some good options include coconut water, sports beverages, electrolyte-mix packets, etc. Be wary of sports drinks that contain too much sugar or artificial flavors/colors. 

#4 Make Sure Your Mid-Run Snack Is More Than Carbs

Endurance athletes who are logging a lot of miles every week will benefit from a carbohydrate-protein blend during a workout.

Numerous studies have found benefits to co-ingesting carbohydrates and protein mid-workout versus carbohydrates alone. Adding protein to the mix helps to reduce post-muscle soreness, enhance mood/energy, restore muscle function, and improve future exercise performance. Our favorite way to do this is with a liquid protein/carb shot. These are small and easy to consume without halting your run and quickly absorbed so as not to upset your stomach.  

#5 Refuel Within The Glycogen Recovery Window 

The glycogen (energy) stores in your muscles are depleted during a long, difficult workout. This depletion is the main cause of mid and post-workout fatigue.

Research has found that refueling with carbohydrates within the first 12-15 minutes after your workout has the greatest effect on the restoration of muscle glycogen. Doing so may also enhance exercise capacity if you are doing a repeated exercise bout. 

Because refueling with protein is also important after a workout, we recommend having a protein/carb combination available immediately after your run. Some runners swear by a glass of chocolate milk for this quick recovery period.

#6 Eat Your Pre-Race Meal at the Right Time 

According to the latest research, waking up 3-4 hours before your race to consume your pre-race meal will provide you optimum time for digestion while also ensuring you are fueled up for the run. Then 15-30 minutes before your run, top off with a highly absorbent collagen protein/carb shot

If you are running a marathon or half marathon which starts early in the morning, you may be tempted to run on an empty stomach or eat right before your race. While some runners may be able to pull this off without digestive upset, ultimately your performance may suffer if you run on an empty or full stomach. Do your best to eat at least 1-4 hours before the race begins. 

#7 Know What To Eat Before A Big Race

Experts recommend eating 1-4 grams of carbs per kg of body weight during your pre-race meal, plus a moderate amount of protein. The earlier you eat it, the bigger it can be. The closer you get to the race, the less food you want in your system. 

Here are a few ideas for a pre-race meal:

  • Oatmeal cooked with milk, mixed with berries or banana and peanut butter, some honey and cinnamon. 
  • Sliced chicken breast sandwich 
  • A bagel and cream cheese or peanut butter and honey
  • Sliced turkey on whole wheat bread 
  • Granola and yogurt with berries 
  • Protein shot with caffeine

When choosing your protein source, whether it be a powder, liquid shot, or whole food, be sure it contains beta-alanine and citrulline malate. These amino acids help to prevent acid buildup in the muscles, increase endurance, delay fatigue, and aid in recovery/repair.

Remember not to eat anything new to you on race day. Choose a meal you are familiar with and have eaten before a run in the past. You don’t want to surprise your body on a race day.

#8 Avoid Meat, Dairy, High-Fat Foods, and Too Much Fiber Before A Race 

As you may have discovered, eating high-fat foods or fibery foods before a run almost always leads to a bathroom break before finishing a race or workout. Heavy foods like dairy and meat will sit in your system and not digest well during a tough workout, and will likely hurt your performance. Try to eat these things several hours before you run, or eat them the day before. 

#9 Read up on Post-Race Recovery Nutrition for Runners 

A race takes an enormous toll on your body, and proper recovery includes good nutrition. You want to eat some carbohydrates immediately following the race to maximize the glycogen recovery window and to help you avoid collapse. In the following couple of hours, you should have some good protein, more carbohydrates, and some fats to fill your system and help your body recover. 

Here are a few snack/meal ideas in the hours following your race..

Immediately after you finish:

Within 1-2 hours:

  • Water
  • String cheese
  • Cottage cheese with crackers
  • PB&J
  • Tuna and crackers 
  • Smoothie with fruit and protein 

Within 4-6 hours:

  • Fluids
  • Chicken breast and vegetables 
  • Salmon and quinoa/vegetables
  • Steak and vegetables
  • Fruit salad

After a hard race, it may be tempting to load up on junk food. While certainly indulging in a treat is perfectly appropriate, make sure the bulk of your calories in the days following your race are nutrient-dense. 

#10 Take Advantage of Caffeine 

Caffeine has many benefits for runners, including improving energy and performance and also helping the body to utilize fat stores more effectively. Many Olympic athletes and professional runners use caffeine to run faster and harder and to improve mental alertness

There is evidence that caffeine helps to reduce a runners perception of effort, which makes running feel easier. Another study on cyclists found that caffeine helped them to complete 15-23% more work than those who didn’t use caffeine, while also experiencing a lower level of perceived exertion. 

Mixing your mid-race carbohydrate with caffeine has also been found to rebuild glycogen stores 66% more than just carbohydrates alone. 

Caffeine also boosts endorphins in the brain, helping you to feel that “runners high” during a race. For a mid-run caffeine boost, try a liquid protein shot with caffeine

How Much Caffeine Is Optimum?

You don’t want to OVERDO the caffeine, and there is a good balance you should try to aim for. Most health organizations agree that one should have no more than 400 mg a day. Depending on how much coffee you drink, you may have a higher tolerance for caffeine. Start small, with maybe 80 mg caffeine before or during a workout and see how you feel. You can slowly increase from there if you feel like you are not getting the desired benefits. 

#11 Eat Enough Protein

The protein requirements for runners and triathletes is generally between 1.2-1.65 grams per kilogram per day. To find your weight in kilograms, simply take your weight in pounds and divide by 2.2, and then multiply by 1.2 and 1.65 to discover your recommended daily protein intake. 

For example, an individual weighing 154 pounds (70 kg) would need between 84 and 115 grams of protein every day for optimum function and recovery. This number may vary based on your personal workout regimen, lifestyle, body type, gender, etc. As an athlete, you know your body better than anyone, so experiment and find out what helps you to feel the best. 

Here are some signs you are NOT getting enough protein:

  • Edema
  • Loss of muscle
  • Slow healing
  • Weak immune system
  • High body fat/decreased lean mass 
  • Fatty liver 
  • Low energy
  • Excessive appetite/unquelled hunger 
  • High risk of bone fractures 

Tracking your food for a few weeks can be helpful to see how much protein you are getting. There are several free apps like MyFitnessPal where you can track your food and get a detailed report on your macro and micronutrients.  

#12 Avoid Nutrient Deficiencies 

There are a few reasons a runner may suffer from nutritional deficiencies. If you follow a strict diet (gluten-free, vegan, grain-free, plant-based, etc), have allergies, are not getting enough calories, don’t have access to a variety of produce, are eating out frequently, are overtraining, or are otherwise unable to consume a well-rounded diet, you may be at risk for certain nutritional deficiencies. 

Female runners have a particularly high risk of being deficient in iron, calcium, and vitamin D. Make an effort to eat enough iron and calcium-dense foods and be sure to spend at least 15 minutes out in the sun every day. 

It is a good idea to work with a qualified dietician or nutritionist if you are a competitive runner/triathlete. They can help you to understand your specific needs as well as identify any areas of weakness in your diet. 

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