13 Science-Backed Tips on Nutrition for Runners & Triathletes

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

Nutrition for runners and triathletes is different than for the average person. 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. 

Whether you are looking for the best supplements for runners, or are preparing for a marathon or half-marathon, equal attention to both your training regimen and your diet is required for maximum progress and performance. 

In this article, we’ve compiled evidence-based tips on nutrition for runners that are specific to your needs as a high-performance individual. 

13 tips on nutrition for runners

Here are our top tips on nutrition for runners and triathletes to help them achieve peak performance: 

1. Calculate your caloric 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. This is our very first tip on nutrition for runners. If you don’t understand your caloric intake well, you won’t do yourself any favors on race day. 

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. 

Based on numerous studies about optimal caloric intake, here are the formulas for finding yours:

Caloric needs for male runners:

  • 50 kcal/kg/day + additional intake to compensate for miles/resistance training 

Caloric needs for female runners:

  • 45 kcal/kg fat-free mass + additional intake to compensate for miles/resistance training 

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 run 

Eating about 30-120 minutes before a run will ensure you have good energy for your workout, and also helps 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. 

When it comes to nutrition for runners, you want to eat mostly carbs. That’s because they will digest easily and provide a quick energy source for your muscles. 

Along with carbs, collagen is a great, easy-to-digest 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 other good pre-run choices may include:

  • Bananas
  • Almond butter 
  • Oatmeal
  • Honey sticks 
  • 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 the 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.

3. Drink the right fluids 

Nutrition for runners isn’t just about food, it’s about hydration, too. 

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 the most of your mid-run snack

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. 

If you aren’t sure what to drink during workouts, a liquid protein/carb shot is a simple choice. These are small and easy to consume without halting your run, and quickly absorbed so as not to upset your stomach. They also provide ample nutrition for runners. 

5. Refuel within the glycogen recovery window 

The glycogen (energy) stores in your muscles are depleted during a long, difficult workout. That’s why nutrition for runners is so important. 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. 

6. Eat your pre-race meal at the right time 

It’s one thing to know the best diet for runners, and another thing entirely to know when to consume it. 

According to the latest research, waking up 3-4 hours before your race to consume your pre-race meal will provide you with 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. Learn what to eat before a big race

The best diet for runners consists of 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

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 high-fat & high-fiber foods before racing 

When it comes to nutrition for runners, you want to avoid eating high-fat or fibery foods before a run. Why? These types of foods almost always lead 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. When working out the best diet for runners, try to cut these foods out of your meals on race day. 

9. Don’t forget your post-race recovery

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:

  • Chocolate milk
  • Granola bar
  • Liquid protein shot
  • Sports drink/coconut water 
  • Banana

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 full of solid nutrition for runners. 

10. Take advantage of caffeine 

Our next tip on nutrition for runners is to consider caffeine intake. 

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

A 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. 

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. Start small, with maybe 80 mg of caffeine before or during a workout and see how you feel. 

11. Eat enough protein

When it comes to nutrition for runners, the protein requirements are generally between 1.2 - 1.65 grams per kg of body weight per day. 

To find your weight in kilograms, simply take your weight in pounds and divide by 2.2. 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.

12. Avoid nutrient deficiencies 

When choosing protein supplements for runners, be sure they contain 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.

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, 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 dietary needs and recommend specific supplements for endurance athletes for you. 

13. Protect your joints

There is a reason we invest so much in the right shoes as runners, and it’s not just for traction. Running is hard on your joints.

So part of finding the right nutrition for runners is finding foods and supplements that will support your joint health. 

If your knees hurt when running, one of the best things you can do is take a regular collagen supplement. Collagen is one of the main structural components of the connective tissues and cartilage in your joints, so a regular supplement can help your body heal your joints from the inside out. 

Make the most of nutrition for runners

You may have noticed us mention collagen many times in this article. If you want a snack that packs the biggest punch, a high-quality collagen supplement is it. 

There are so many collagen benefits for men and women alike, and especially for athletes. 

Collagen supplements are an important part of nutrition for runners because they can provide you with the carbs and protein that are so needed before, during, and after your race.

Collagen can also protect your joints against injury and help you run longer distances without aches and pains. 

If you’re looking for the top collagen supplement for runners, Frog Fuel liquid protein shots provide you with all the needed nutrition for runners, plus beta-alanine and citrulline malate for improved performance. And there is even a caffeinated option!

Best yet, this protein supplement comes in a single-serving pouch that is easy to throw in your pocket – and the nano-hydrolyzed formula makes it easy for your body to digest and utilize in just 15 minutes.


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