The Best Diet For Peak CrossFit Performance

There is a lot of interest in nutrition among CrossFitters because improving performance is equally dependant upon recovery as it is upon workouts. Working out with poor nutrition rarely leads to improved strength or endurance.

Nutrition is about fueling and healing. Maintaining a healthy diet means supplying enough micro and macronutrients to cells to promote growth, healing and balanced function. When we throw CrossFit into the mix and demand the utmost of cells to perform and coordinate athletically, nutrition should become of utmost importance.

Crossfit combines strength with explosive power and endurance. Combining all these athletic disciplines is what makes CrossFit so unique. Powering all these different systems requires an equally unique diet that offers enough energy to last through a WOD while also healing and replenishing as quickly as possible to allow for performance gains.

 Energy Systems and Performance

Energy Systems and Performance

Power and explosiveness are primarily exemplified in snatch and clean movements. Training this does not require a huge amount of calories for training, but does require a lot of fats and protein for recovery. Power training is draining on the central nervous system because coordinating speed movements trains and retrains neuromuscular pathways.

Strength movements like squats, deadlifts, thrusters and muscle ups all require quite a bit of calories before, during and after training, along with a decent portion of protein for recovery. Strength movements drain muscles of energy fast, so for the first few minutes, the system is working off ATP that is already stored in the muscles ready to go, and then requires oxygen combined with glucogen to metabolize more ATP.

Finally, endurance events are much more than running and rowing when it comes to CrossFit, as so many WODs require a lot of metabolic conditioning. The slow steady pace of endurance-based WODs requires a slow and steady supply of energy, usually metabolized from either carbohydrates or fats, depending on the diet of the individual.

During more endurance and steady-state workouts, the body is able to perform quite well by consuming a diet rich in fats and proteins which are then metabolized into energy during workouts. When an athlete has a carbohydrate-rich diet, there is more glucose available in the muscles. Glucose in the system can be rapidly oxidized to create more energy compared to fats. That means when the demand for energy is high- during a high intensity workout- you can expect the energy from fats to diminish unable to metabolize at a rate fast enough to sustain larger energy demands. The body needs quick-fuel from carbohydrates instead.

But if we need carbohydrates to sustain a classic high intensity WOD, how can you also alter body composition and maintain a diet high enough in carbs to maximize performance?

A lot of it comes back to recovery. During the recovery period, a good macronutrient balance timed correctly with WODs makes all the difference between winning, losing, personal records and consistency.

In the minutes and days that follow a WOD, recovery nutrition is extremely important. A balanced diet with enough carbohydrates, fats and proteins throughout the day, in the correct portions, is the answer.

 Macronutrients Understanding Protein Carbohydrates Fats

Macronutrients: Understanding Protein, Carbohydrates, Fats



Research has shown that consuming carbohydrates following a workout is very helpful in maintaining a better net protein balance, which compares the protein breakdown to synthesis (Børsheim, et al). This group of foods encompasses all things grown in the earth. Pretty much all plant-based foods are carbohydrates. There are a variety of types of carbs; for example, fruits, legumes, beans, starches, grains, etc. It is important to remember that not all carbs are bad, nor are they equal. Each type of plant based food also has its own share of the fats and proteins as well as vitamins and minerals.

The old idea general concept of “carbohydrates are bad” is an extreme fear-based misconception. Certain functions are primarily fueled by carbohydrates and nothing else, including the eyes and brain. Having a nutritious breakfast is critical to get your day started ri

When we talk about good and bad carbohydrates, there are a few things to consider. First, some carbs are very highly processed. The health community has come to a general consensus that the more a food is processed, the farther away it is from a healthy option. Whole brown rice, for example, is less processed than rice crackers. It also contains fat and protein, which are usually degraded during processing and become irrelevant. Some carbohydrates have more diverse micro and macronutrient profiles than others. Again, not all carbs are 

Next, consider the glycemic index (GI) of the carbohydrate you are about to consume. Depending on the time of day and workout schedule, you may choose to consume slow burning (low GI) or fast burning (high GI) foods. Most fruits, veggies, legumes and nuts are slow burning; you can expect slow and steady release of energy and they do not spike blood sugar. Processed grains, such as rice crackers and breads are high GI, with a more immediate effect (Harvard Health Publishing)

Carbohydrates are a necessary and healthy part of any Crossfitters diet. Timing and portioning are guided by the athlete needs and schedule.


When we are talking about proteins, we are actually talking about several essential and non-essential smaller nutrient blocks that form proteins. Amino acids are either formed in our body (non-essential) or we absorb them through foods (essential). Any protein source, be it a supplement, animal or plant-based, has a unique amino acid profile. The function of amino acids and proteins is to heal and repair body tissue. Muscles, connective tissue and organ tissue are all made up of proteins.

There is an abundance of research on the effect of protein on muscle recovery. The general consensus is that protein is absolutely necessary to minimize protein breakdown following resistance training. It is totally normal for proteins to be breaking down in the body, a process called catabolism. By feeding the system, it reduces the effects and synthesizes more protein (West et al, 2017).

Low and moderately active elder individuals can also benefit from a high protein diet. Simply consuming more protein (though there is a recommended limit) can reduce the effects of muscle atrophy significantly. Since protein is not stored in the body and takes time to process, consuming small and frequently sources is generally recommended. After grueling training days, slow burning proteins (such as casein) which digest through the night are also a nice way to manage intake.

We often hear about “BCAAs” and resistance training. These are three essential “branched-chain amino acids” which have been identified as the most responsible for building muscle (. Leucine, isoleucine, and valine supplements are very popular for this reason.

A recent study also proved that consuming both carbohydrates and protein together immediately following difficult endurance exercise significantly improves next-day performance (Sollie, et al 2018). This is noteworthy because of the style of CrossFit competition; multi-day staged workouts.


Finally, the dreaded fats, which had a bad reputation for most of the past 60 years, and continues to perpetuate myths. Surprise, fat is good for us. We need fats for several functions, including energy production, fat metabolization, nervous system maintenance, and for the absorption of vitamins.

Never again should you reach for a “low fat” option. Moderation and choice can make your fat consumption joyful and guilt free again. Fat makes food taste good to humans, so why deprive ourselves. And similarly to carbohydrates, gets a bad reputation, when it is really just how we choose to consume and use fats. Either way, this macro is going to be essential to your recovery and improved CrossFit performance.


Micronutrients include vitamins and minerals. These are the molecules that keep us moving, healing, building, thinking and functioning. All of the micronutrients we need can be found in food sources and in sunlight. Think of micronutrients as the zero-calorie magic that keeps us functioning. Micronutrients should exist in perfect balance with each other within the body. That means that too much can be harmful. When we are low in a particular micronutrient, it is called deficient, but when it is in excess, it is considered toxic. Scientists have defined a healthy or normal range for each micronutrient to be found in our body, most of which can be tested through urine or blood samples.

For health, you want to have enough, but not too much. Many nutrients will simply be flushed out through urine if there is too much, but not always. Exceeding the Upper Tolerable Limit is dangerous. Too much of anything in the system can make the blood toxic. Overdoing it with vitamin and mineral supplements without being recommended by a doctor is not a great idea for this reason.

What we do know and believe is that variety is key. Frequent balanced meals that contain a wide variety of macronutrients will give any CrossFit athlete the fuel they need to perform. To help organize your meals and find when you need supplementing, check out these CrossFit diet options:

The top three diets for CrossFit

Top 3 Diets For CrossFit Performance

In the early days, we were told to eat “Paleo”. The problem with that was that athletes were getting tired fast, from a lack of complex carbohydrates. Now, with a more organized and balanced approach, you can get lean while getting enough energy to WOD and recover quickly. Here are three diets a lot of CrossFitters are turning to, to help them stay healthy while providing the fuel they need to perform at their peak.

The Zone Diet

The Zone Diet

This was designed and written about by Dr. Barry Sears and has been adopted by many CrossFitters. This takes an approach of 40:30:30 for macros. Of the entire daily intake, 40% should be carbohydrates, 30% should be protein and 30% should be 

Each meal and macro is broken down into ‘blocks’ there is a whole system to follow that explains the portion size of a block. Depending on the athlete's bodyweight, objective and sex, the number of blocks can differ.

The 30% recommendation for fat is much higher than old school diets which recommended as little as 5% for good health. We know that fat metabolizes fat for energy, carries a lot of calories, and with good fat choices, can improve cardiovascular health. This ratio is also said to help balance hormone levels between insulin and glucagon and does not spike blood sugar levels.

The zone diet is far less restrictive when it comes to food sources. If your carb consists of a chocolate bar, then so be it! Simply focusing on keeping each meal within the ratios is what is recommended. If you need to supplement here and there, the zone allows you to do so, with a clear guide of how and when to consume which portions.

The slow carb diet by Tim Ferriss

The Slow Carb Diet

We like this diet because it is an easy way to get into clean and healthy eating. The slow carb diet is based on Tim Ferris’s 4-hour body book. We would recommend this to new CrossFitters who want to transform their body. There are 5 food groups, 5 strict rules, and a few details to keep in mind.

The food groups:

  • Protein
  • Vegetables
  • Legumes
  • Fats
  • Spices

You can eat as much as you want of the first three, and a limited amount of fats and spices.

The rules:

  • No “white” carbs
  • Eat the same few meals over each day
  • Don’t drink calories
  • Don’t eat fruit
  • Take 1 day off as a cheat day each week

The no white carbs serves as a guide to the generally less healthy foods like white sugar and refined flour, potatoes and pasta. In eating the same few meals the idea is getting familiar with cooking with the most nutrient rich foods while keeping it simple and easy to follow. According to the slow-carb diet, there is no reason to make things complicated with recipes. Simple, nutritious and effective recipes will do.

Drinking calories refers primarily to sodas and other sugary drinks. Generally, fruit would be considered healthy, but in this case, the fructose is considered too sugary for a snack. However, on your cheat day, everything and anything is in play, including alcohol.

What we like about this diet is its simplicity. The simple rules make it realistic and easy to follow. Since portions are not particularly regulated, you can eat more than the recommended 4 meals by adding in snacks made of protein or veggies, or both. 

Finally, this diet is a great option if you're on the go or traveling a lot. All you need to do is make sure you're ordering a clean protein source, a small serving of slow digesting carbs like black beans and a healthy serving of vegetables and you're set. 

If It Fits Your Macros Diet IIFYM Diet 

If It Fits Your Macros (IIFYM)

Finally, the most flexible version of a CrossFit diet is IIFYM. With this system, we consider the individual needs of each person based on the level of activity, age and size, and calculate how much of each macro this person should consume, measured in grams.

There is an online calculator you can use to determine your macros. Every person has a BMR or basal metabolic rate, which is the amount of energy you need just to be a blob on the sofa. Add in your lifestyle, activity intensities, and you’ll have a pretty good idea of what you need to gain or lose weight, measured in grams of food.

For example, if the average woman needs 2500 calories to perform, but wants to gain some mass to increase strength, the number of macros is adjusted to increase 60:30:10. More carbohydrates to help with the gains, and more overall calories. For weight loss, the ratio shifts a bit to reduce carbohydrates to 50:35:15. The total number of calories is about 15-20% under what your body consumes, to create a deficit and turn up fat-burning.

While healthy and whole foods are recommended, it is completely up to the athlete to decide what foods work for them. Since every person has a different health history and unique dietary tolerances, this diet works for a lot of people.

The Best Diet For Peak CrossFit Performance

Regardless of which diet you decide to try out, they all have one similarity; whole and healthy foods are always recommended. Maintaining a high protein diet can be difficult for many, but whey and other plant-based protein supplements show very good results as a stand-in for high protein whole foods.

Grass-Fed Whey Protein Isolate and Colostrum


Elisabet Børsheim, Melanie G. Cree, Kevin D. Tipton, Tabatha A. Elliott, Asle Aarsland, and Robert R. Wolfe. 2004. “Effect of carbohydrate intake on net muscle protein synthesis during recovery from resistance exercise.” Journal of Applied physiology. Retrieved from:

Daniel W. D. West 1,Sidney Abou Sawan 1,Michael Mazzulla 1,Eric Williamson 1 andDaniel R. Moore (2017). “Whey Protein Supplementation Enhances Whole Body Protein Metabolism and Performance Recovery after Resistance Exercise: A Double-Blind Crossover Study”. Nutrients 2017, 9(7), 735. Retrieved from:

“A good guide to good carbs: the Glycemic index”. Harvard Health Publishing. Retrieved from:

Ove Sollie, Per B. Jeppesen, Daniel S. Tangen, Fredrik Jernerén, Birgitte Nellemann, Ditta Valsdottir, Klavs Madsen, Cheryl Turner, Helga Refsum, Bjørn S. Skålhegg, John L. Ivy, and Jørgen Jensen (2018) “Protein intake in the early recovery period after exhaustive exercise improves performance the following day” Journal of Applied Physiology. Retrieved from:

“IIFYM (if it fits your macros): A beginners guide.” Healthline. Retrieved from:

Leave a comment

Please note, comments must be approved before they are published