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What to Eat Before Cardio? (According to a Dietician)

Michael Garrico
Published by Michael Garrico
Fact checked by Donald Christman, BHSc FACT CHECKED
Last updated: August 30, 2022

As a personal trainer, I often plan a cardio workout for clients around their daily meal plans. This is important to achieve the right balance of protein, carbs, and fat to support what your body needs during and after training.

But people often get confused about what exactly they should eat and when the best time is.

So, I teamed up with a sports nutritionist and registered dietitian to look into what scientific literature was available to come up with an ideal plan for athletes.

Here’s what our research revealed.

Quick Summary

  • Fueling a cardio session comes down to mainly getting energy from carbs and protein, and there are ideal macro balances to achieve.
  • While fasted cardio on an empty stomach is a good way to burn fat and lose weight, not all athletes have that as a goal.
  • For longer workouts, you need to make sure you eat the right kind of food to boost your glycogen stores.

What Food Should You Eat For Cardio?

Close up image of low carb foods

You should eat food that is rich in protein and complex carbs for cardio.

The complex carbs can help balance the fuel requirements your body has and, with the right timing, can give you a good performance boost [1]. More on that shortly.

The protein can then also help your muscles perform better, but it’s also a valuable macro to prepare for muscle recovery after your workout [2].

It shouldn't be a replacement for a post-workout shake, but it’s a good idea to stock up on amino acid supplements.

Here are four simple snacks that you can either buy ready to eat or make within just a few minutes.

  1. A small bowl of oatmeal topped with nuts and seeds for healthy fats
  2. Fruit smoothie with frozen berries and greek yogurt for a protein boost
  3. Granola bar with coconut oil
  4. Whole wheat bread with almond butter and cottage cheese

You’ll see in these recommendations that there are some foods that contain sources of healthy fats.

The reason we don’t recommend loading up on fat is that it’s slow to digest, and you need the energy released for your exercise routine [3].

How Much Should You Eat For a Pre-Workout Meal?

Top view of an avocado and salad

You should only eat a small portion as a pre-workout meal.

What I mean is that you want to avoid eating a large lunch or dinner within a few hours of cardio workouts [4].

More on timing shortly.

What I recommend is eating up to 300 calories of food for this snack. It’s very much dependent on whether your goals are maintaining weight or bulking up fast.

And your overall physique, strength, and intensity of workouts could also increase or decrease that number.

But you want to avoid eating too much more than that as you may feel bloated during training.

Getting The Timing Right

What I would suggest is eating a small snack about 45 to 60 minutes before a cardio workout.

That should be long enough for your body to start the digestion processes and release the energy in the carbs and protein.

A small meal or smoothie is ideal for that 60-minute window before a workout [5].

And the closer you can get a boost of protein before a training session, the more you can prepare your body to reduce muscle damage in the recovery period.

What Shouldn’t You Eat Before Cardio?

Junk foods with high carbs

You shouldn’t eat junk foods or sugary treats before a cardio session.

This also includes a type of sports drink that is more likely to cause blood sugar spikes [6].

Keep in mind that this could make it difficult to burn fat while doing cardio exercises as there’s surplus energy available.

I’ve dealt with many clients who drank these sugary drinks before and during training only to struggle with weight issues as a result.

“People who experience bigger dips in blood sugar report greater hunger and tend to eat more calories overall than people with smaller dips in blood sugar.“

- Lauren Bedosky, Writer at Everydayhealth.com.

And I also want to make sure we define junk food.

This isn’t just burgers, fries, and pizza. But it’s anything highly processed that includes lots of simple carbs and unhealthy fat [7].

It’s low in the nutrients you need for your muscles to perform and high in the “nutrients” that mess up your performance and health.

No matter what your fitness goals are, steering clear of such foods can help you avoid many health conditions that can have a huge toll on your body.

FAQs

Is It OK To Do Cardio Right After Eating?

Yes, it is OK to do cardio after eating, but you need to give yourself some time. If you’ve had a large meal, then aim to wait at least two hours.

But for a small snack, it’s OK to start exercising your body about an hour later.

Can You Do Cardio After Breakfast?

Yes, you can do cardio after breakfast. Aim to eat a light breakfast of complex carbs and protein and reduce the amount of energy you get from fat.

That should make you feel less bloated during your workout.

Fuel Your Workout The Right Way

There are times when training on an empty stomach is a great way to achieve faster weight loss.

But in most cases, athletes will need to power through a cardio session with readily available rather than a stored form of energy.

Have one of the above small snacks, and then also consider adding a pre-workout supplement by checking out our list of recommended products:

These won’t turn you into a superhero overnight, but the small boost you get in each workout can add up to significant fitness improvements in the months ahead.


References:

  1. https://pubmed.ncbi.nlm.nih.gov/32386289/
  2. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6142015/
  3. https://www.ncbi.nlm.nih.gov/books/NBK53550/
  4. https://health.clevelandclinic.org/what-to-eat-before-and-after-a-workout/
  5. https://blog.nasm.org/workout-and-nutrition-timing
  6. https://pubmed.ncbi.nlm.nih.gov/8936126/
  7. https://medical-dictionary.thefreedictionary.com/junk+food

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