Close this search box.

Ask the Dietitian: How to Fuel Your Running with Real Food

I have a confession: I’m not the healthiest eater. I love junk food and it’s not something I’m ashamed to admit.

Bring on the chocolate chip cookies and eggnog!

But for most runners, a good nutrition plan is a top priority. A sound diet will help you recover more effectively, bring you closer to your goal weight, and properly fuel your workouts and races.Dietitian Cassie

Since I’m not a nutritionist (nor do I play one on the interwebs) or even remotely qualified to dispense advice on dietary planning, I want to bring you someone who knows her stuff.

Meet Cassie Bjork, better known as Dietitian Cassie. She’s a registered, licensed dietitian, health coach and four-time marathon finisher who is passionate about helping people establish a balanced lifestyle through whole foods and exercise.

Through her company, she focuses on debunking rumors, myths, and fads and teaches people how to eat healthy by breaking down research-based material into practical, actionable advice.

Cassie believes in using real food for optimal health and performance – and so do I (when I’m not binging on Ben & Jerry’s). That’s why I asked her to come on Strength Running today and drop some knowledge about how runners can use the power of real, actual food to help their running.

Let’s get to the interview!

Marathon Fueling 101

Jason: Every marathoner knows that a good race depends not just on training, but on proper fueling. What’s your preferred method of fueling for the marathon both in the days leading up to the race and during the race itself?

Cassie: Whether I’m training or not, I strive to eat a balance of protein, fat and carbohydrates (PFC!) at all meals and snacks. I have found that the key to consistent energy levels, staying focused, keeping cravings away and maintaining energy through my runs without “hitting a wall” is eating a balance of PFC every 3-4 hours during the day.

The days leading up to a marathon, I load up not just on carbohydrates, but proteins and fat too. I eat more overall. I’ve found that when I eat more fat, I don’t need to fuel as frequently during the race.

My favorite pre-race evening meal is 5 ounces of tilapia or salmon cooked in butter or coconut oil and topped with a full avocado, served with a sweet potato and a giant salad (carbohydrates). My bedtime snack the night before the race is usually a cup of berries with a few tablespoons of heavy cream and some pistachios or almonds. My breakfast every morning, including race day is eggs (protein) cooked in butter (healthy fat) with cooked vegetables and on race day I use extra butter and also have a banana on the side.

During the race I fuel with real food as much as possible. I eat fresh fruit offered by spectators and I designate friends or family at certain points along the race to have real food for me. My favorite running fuel is banana with peanut or almond butter, grapes, almonds, sunflower seeds and pumpkin seeds.

I’ll bring coconut oil with mashed up banana and keep it in my pouch along with a bag of almonds, raisins and craisins. I sip water along the course unless I hit the wall then I may have some sports drink.

Post-Workout Fueling

Jason: Do you have a favorite meal to eat after a long run or particularly challenging workout?  What meal covers every nutrition need for distance runners?

Cassie: My favorite post-workout meal is one that includes every essential macro-nutrient that runners need: eggs cooked in real butter with spinach. I’ll usually also have a fruit or vegetable on the side such as a banana or a sweet potato sauteed in coconut oil. This meal is simple but it’s incredibly nourishing for the body and includes all three macro-nutrients: Protein, Fat and Carbs. If it doesn’t seem like enough food, then add an extra egg or two, some cheese or avocado for extra fat, and some fruit for extra carbs.

Eggs are the most bio-available source of protein which means they’re easily absorbed and provide nourishment to your body immediately. Butter is a healthy fat that will heal inflammation that occurs during running and spinach provides carbohydrate to replenish the stores that were used for energy during the run.

Any other form of meat is also great protein for your body post-workout. If you buy grass-fed meat, there’s no need to go lean. Your body will utilize the animal fat for recovery. In low-quality meats, the fat contains several harmful toxins which have the opposite effect, so in this case it’s beneficial to buy leaner meat and add fat such as butter or avocado. All meats are great sources of protein too: chicken, beef, turkey, venison, buffalo, fish, and other seafood. Animal protein is most like the human body, so sources of animal protein are most beneficial for recovery and repair. When you think of protein, think of meat, fish and eggs.

Do You Make This Mistake With Your Diet?

Jason: What are the most common dietary mistakes that you see runners making and how can they fix them?

Cassie: The biggest, most damaging, risky mistake I see runners making is following a low-fat diet. Runners NEED fat to to lubricate and protect their joints and organs, to aid in recovery, help their body with temperature control and the absorption of nutrients, and to keep their body fueled and appetites satisfied.

Low-fat diets for runners are INCREDIBLY damaging. I encourage all runners to include nuts, seeds, avocado, coconut oil, coconut milk and real butter in their daily intake.

Balancing Carb Needs with a Real Food Diet


Jason: During more intense training, how do you balance the need for carbohydrates for fuel and avoiding processed, sugary food?

Cassie: I’ve never found the need for processed, sugary food during intense training — I eat as much real food as I can to support my body and provide it the energy it needs.

One of my favorite, real food carbohydrate sources is fruit. It’s a portable carbohydrate that’s full of nutrients. Dried fruit is also great (like apricots, raisins, craisins and banana chips) and I can bring all of these with me on my run, too. I also like sweet potatoes because they pack in a lot of carbohydrate along with fiber to help balance out blood sugar levels.

Smoothies are a great way to pack in nutrition, as you can blend veggies and fruits for carbohydrate, heavy cream or avocado for healthy fat, and protein powder or a few eggs for protein. They’re balanced and you can simply make a bigger smoothie to pack in the nutrition your body needs for more demanding, intense workouts.

What’s Your Fueling Strategy?

I’ve admitted that I have a weakness for junk food even though I know that a proper diet for runners includes mostly real, whole food.

During marathon training or while you’re running fast, intense workouts for shorter races like a 5k, it becomes all too easy to reach for that sugary post-workout bar instead of taking the time to prepare something more substantial and healthy.

These days, I’m working on several ways to maximize my nutrition, refueling, and diet so that I can optimize my running and recovery. Here are a few strategies that are working for me:

Make a giant smoothie. Once or twice a week, I blend a big smoothie that lasts me about three days. Inside, it has everything:

  • Frozen berries
  • Banana
  • Raw greens (usually kale or spinach, but sometimes something random like mustard greens)
  • Whey protein powder
  • Ice and a cup of water

If I’m craving more fat, I’ll add a scoop of peanut, almond, or sunflower butter or coconut oil. You can never have too much coconut oil!

Eat veggies at every meal. This is a simple strategy that ensures I’m getting more vegetables every day. And since I think you can never eat too many vegetables, this is a win-win. Here’s how I do it:

  • Breakfast: omelette with sauteed peppers or spinach, topped with guacamole
  • Lunch: leftovers from dinner the night before
  • Dinner:  cooked vegetables plus a salad

If you’re aware of your veggie intake at each meal, it’s actually surprisingly easy to include more every day. This strategy is also great for those runners who need more help with weight management.

Now, I want to ask you: what diet strategies, health hacks, or nutrition tips work for you? 

If you’re stuck, get our e-course on nutrition for runners – totally free. You’ll see the latest diet, weight loss, and nutrition tips to maximize your diet for running.

Please also join me in thanking Dietitian Cassie for helping with this article! If you want more advice on healthy eating (particularly for runners), make sure you sign up here.

Get Stronger & Run Healthy

Join our free course to help you better prevent injuries, develop runner-specific strength, and avoid the big mistakes that get runners hurt.