You either know what a macronutrient is or you don’t. Even if you know what a macronutrient is, it might be unclear what the macros for CrossFit are. Macros and macro ratios are kind of like gluten: a lot of people make dietary choices based on them, but don’t know why they are making these choices.

Jimmy Kimmel did an entertaining take on Jay Leno’s “Jay Walking” segment. He took to the streets with a camera and microphone asking people what gluten is. Nobody answered that gluten is “a protein in wheat,” even though they followed a gluten-free diet.

I presume that I would get similarly incomplete answers if I went into a gym and asked, “what are macros?”

For that reason, I am going to educate you about what the three macronutrients are, their role in the body, and how to apply this knowledge to create an action plan for a macronutrient diet plan that supports your CrossFit training

You work hard, you should be seeing the results you want, and this is an important step in that process!

You will make informed decisions about your diet if you understand what macros are, how the body uses macros, and how exercise affects the amount your body needs. Armed with this knowledge, you can decide for yourself about whether the ketogenic diet right (it’s not), or whether the “perfect” macronutrient ratio for CrossFit performance exists!

This article will give you the tools you a framework for finding the macronutrient ratio that works for you!

For your guide to macros Click Here

What are Macronutrients?

Macronutrients are the 3 nutrients from which the body regenerates energy. These are carbohydrate, fat, and protein.

Through digestion, the body breaks down the macronutrients in the food we eat into smaller parts that it can use for energy, energy storage, and other functions like tissue repair.

  • Proteins break down into amino acids.
  • Fats break down into fatty acids and glycerol.
  • Carbohydrates break down into monosaccharides and usually convert to glucose.

Each macronutrient provides a certain amount of energy, measured in the familiar calorie.

  • Protein has 4 calories per gram
  • Carbohydrate has 4 calories per gram
  • Fat has 9 calories per gram

When it comes to achieving your fitness goals, calories play an important role.

  • If you want to lose weight, you need to eat less than you burn.
  • To gain, you must eat more than you burn.
  • To maintain, you must balance calories ingested with calories burned.

Calories, however, do not give us the whole picture of health and how to reach our goals. Each macronutrient has its own role in the body beyond the provision of energy. Depending on your goals, it is important to know about the functions of each macronutrient to determine how much your body needs.

First, we will explore protein.

Protein’s Role in the Body

Protein, as a macronutrient, should be the main focus of the CrossFit athlete and anybody who does resistance training. The body uses protein for:

  • Tissue structure and function (ie. muscle).
  • Enzyme and hormone production.
  • Energy (through gluconeogenesis).
  • Immune system function.

I say that protein is the most important macronutrient to focus on eating because your body is constantly rebuilding its tissues. Your body has a small “pool” of amino acids it can draw from, but imagine this pool like a bathtub with no stopper. To keep it full, it needs a constant flow from the outside.

Your body will cannibalize its muscle tissue without an adequate supply of essential amino acids from diet. Chronic protein deficiency will lead to an eventual shutdown of vital functions. Exercise increases your body’s need for amino acids from dietary protein.

The Effect of Exercise on Protein Needs

Exercise causes stress to our muscles. This stress sends signals to suggest that our enzymes aren’t working well enough to meet the energy demands of exercise. It suggests that the proteins that transfer energy in and out of the cell don’t work fast enough. The signal also tells the body that its contractile proteins aren’t strong enough.

In response, the body starts by turning over proteins to rebuild a stronger system. The breakdown of inadequate contractile proteins and enzymes begins, and amino acids from diet build new ones. This makes the muscle better at doing its job next time.

This process requires an adequate supply of amino acids from food. If you do not consume enough protein, your body cannot create new-and-improved muscle tissue. So, it is important to make sure you eat the right macros for CrossFit performance.

And what about experience? Interestingly, new strength athletes have higher protein requirements than experienced strength athletes.

This seems counterintuitive. You would think a trained athlete with more muscle, lifting more weight, would need more protein to support that muscle. But studies show that — pound for pound — the untrained athlete needs more.

The hypothesis is that an experienced athlete is fighting for small muscle gains, while the newbie sees rapid muscle gains.

How Protein Burns Fat

When my clients first start logging their food intake in MyFitnessPal, I often find that they are eating far less protein than they think. This also means they eat significantly less than they need to improve their performance and body composition. For most people, a correction in the amount of protein they eat is enough to kick-start weight loss or overcome skinny-fat syndrome.

One reason might be that protein has a significant thermic effect. The thermic effect of food is the amount of energy the body expends breaking down, using, and storing the energy from the food you consume.

Each macronutrient has a thermic effect, however, the thermic effect of protein is 2-5 times greater than that of carbohydrate and fats. We are all slightly different when it comes to the thermic effect of each macronutrient.

To illustrate the thermic effect of food, let’s assume that my digestive system uses 20% of the energy in protein for processing and storage. If I eat 200g of protein, or 800 calories, 20% or 160 calories get burned due to the thermic effect.

By eating a higher ratio of protein to carbohydrate or fat, you take advantage of this thermic effect. Eating more protein is key to body recomposition and the first thing to address when looking at macros for CrossFit.

If you are thinking, “But Matt, I want gains; does this mean I should eat less protein?”

Not necessarily. You also need to eat enough protein to support lean muscle mass by encouraging protein synthesis. Muscle protein synthesis will not occur if you do not feed your body an adequate amount of protein.

So what is the right amount of protein for you?

Ideal Macros for CrossFit: How Much Protein?

Whether your goal is fat loss, muscle gain, or performance, you should be eating roughly the same amount of protein.

Some research on protein needs shows that 0.82 grams per pound of bodyweight is the upper limit that benefits body composition in trained strength athletes. Above this level, improvements in muscle protein synthesis are very incremental but still exist.

For athletes whose focus is on mass gain or performance, you should eat at this upper limit. For a 150lb athlete, your goal is 123 grams per day.

For athletes who are on a caloric deficit diet to lose weight, a slightly higher protein intake will help. The higher protein will spare the cannibalization of lean muscle tissue. You should eat closer to .9 grams of protein per pound of bodyweight, or more. If you weigh 200 pounds, this pegs your protein needs at 180 grams per day.

Protein is not the only consideration, however. Carbohydrates are a very useful macronutrient for athletes whose training includes resistance exercise.

Carbohydrate’s Role in the Body

Carbohydrates are important because they are a fast-acting macronutrient for energy.  Unfortunately, our body’s storage of them is relatively limited. For this reason, it is important to get an adequate supply of carbohydrates in our diet.

Our bodies break carbohydrates down into glucose during digestion, and for good reason. Your brain is a needy little organ that accounts for about 60% of the body’s energy expenditure at rest. The only source of energy it uses (except during periods of starvation or low carbohydrate intake) is glucose!

Unfortunately, unlike the muscles, the brain cannot store energy, so there needs to be a consistent supply available in your blood. This, however, does not mean you need to consistently eat carbs throughout the day. Your body stores some glucose in the liver and can also manufacture carbohydrates from fats and proteins. This happens through a process called gluconeogenesis.

The muscles also require carbohydrates for energy, especially during high-intensity exercises like CrossFit and interval work. This makes it important to fuel your body with carbohydrates on training days. Especially during the pre and post-workout period.

Macros For CrossFit: The Effect on Carbohydrate Needs

Carbohydrate stored in your muscle is the primary fuel used during short, high-intensity exercise. As we learned in the protein section, our muscles break down from the stress of exercise, and our bodies want to rebuild them to be more effective.

Interestingly, the first priority of your body after high-intensity exercise is to replenish its muscle carbohydrate stores (called glycogen). Even before it starts to repair the muscle tissue. To facilitate this process, your muscle cells become insulin sensitive post-exercise.

You can think of insulin as a storage hormone. It helps regulate the amount of glucose in your blood. Too much glucose can be toxic, so it signals your body to release insulin to remove it and store it for future needs.

After you exercise, your muscle cells really want to replenish and store glycogen. You can do this by eating a meal or drinking a shake consisting of protein and carbohydrates. The carbs and protein will stimulate the release of insulin, and the insulin-sensitive muscle cells absorb the amino acids and glucose to kick-start recovery.

Do Carbs Make You Fat?

Just as the body can convert protein and fat into glucose, it can also turn glucose into fat. This happens when energy demands on the body are low, carbohydrate and calorie intake are high, and insulin concentration is high.

What this looks like is a lot of sitting, little exercise, general overeating and lots of processed carbohydrates and sugar.

As I mentioned earlier, too much glucose in the bloodstream is toxic, so insulin helps move glucose from the blood into long-term storage. After exercise, our muscles are insulin-sensitive and will take up the glucose.

The liver can actually store about 400 calories or 100 grams of carbohydrate as glycogen. After the liver, the muscles get their fill of carbohydrates. The more muscle mass you have, the more glycogen you can store in the muscle. The estimated maximum glycogen storage of muscle is between 300 to 600 grams.

If you are sedentary, carry excess body fat, and have low muscle mass, your muscle glycogen stores are full because exercise has not depleted them.

Instead of using ingested carbohydrates for muscle and liver glycogen replenishment, insulin will shuttle the glucose into your fat cells where it is combined with fatty acids and stored as a fat cell.

For this reason, carbs can make you fat. But, if you noticed I said that this process occurs when both calorie and carb intake are high, or if you already carry excess body fat. For a healthy individual who trains regularly and eats fewer calories than they are expending, their body is probably not going to hang on to that excess carbohydrate as fat unless you eat an extreme excess.

Each of us is different in our tolerance of carbohydrates, and how each body reacts to their ingestion is unique.

As a general rule, if you are already carrying excess fat, or are the type of person that gains a pound just looking at a donut, you want to eat a lower percentage of your total macros.

If you are skinny and have trouble putting on mass, or if your goals are athletic-performance oriented, you will want to eat a higher percentage of calories from carbohydrate.

More on how much carbohydrate to eat, and the best macros for CrossFit shortly. First, let’s explore fat as a macronutrient.

The Role of Fats in the Body

The media demonizes dietary fat, but fat plays a critical role in our bodies. Our bodies use fat for:

  • Plasma membrane structure (protects cell, substance transport).
  • Brain and nervous system tissue.
  • Hormone function.
  • Transports fat-soluble vitamins to cells.
  • Fuel source— the largest in the body.
  • Insulation and temperature regulation.

Macro Ratios For CrossFit: Does Exercise Affect Fat Needs?

Not directly.

As we have seen, exercise creates an immediate need for the consumption of both protein and carbohydrate to facilitate energy replenishment and tissue repair. How does it affect our need for dietary fat?

The short answer is, it doesn’t! Dietary fats are more important for nervous system function and hormone production than muscle repair. The body will use fat for energy during and after exercise, but it is not necessary to consume fat for recovery.

Our body has limited stores of carbohydrate and amino acids, both of which exercise depletes. It is necessary to consume food with these macronutrients for optimal recovery.

We not only have a massive amount of energy stored as fat, but our bodies can manufacture fat from glucose if necessary.

Even a very lean person has an almost unlimited store of body fat. Let’s take an 180-lb. male at 10% bodyfat. They would have 18 lbs. of stored fat, or 8164 grams. At 9 calories per gram of fat, this means the athlete has over 73,000 calories of stored energy. For reference, you could run 21 marathons on those fat stores alone!

When Does the Body Use Fat For Energy?

The body uses stored fat for energy during periods of low energy demand, such as during daily non-exercise activities. It also uses fat for energy during long-duration and low-intensity exercises such as walking or swimming. Rest periods between high-intensity exercise are another time when the body likes to use fat.

High-intensity exercise can increase the body’s demand for fat during daily activities and at rest in the post-exercise period. The body prefers carbohydrate during the high-intensity exercise, though.

The Best Macronutrient Ratio For CrossFit

The perfect fat-carb-protein ratio for CrossFit…depends. It depends on many different factors. There is no one-size-fits-all recommendation, and anybody who says otherwise has worked with few clients or is plain stubborn.

The first two factors that you need to consider are your goal and starting point.

I say goal (singular) because some clients come to me and say, “I want to lose fat, gain muscle, and PR my squat.” These goals are not necessarily mutually exclusive, but you need to focus on one at a time, and the sequence is important.

You need to establish the primary goal you want to achieve. If it’s fat loss, I am going to prescribe a different macronutrient ratio than if you want to PR your squat.

Your starting point is also important. If you are obese, I am going to prescribe a different fat-carb-protein ratio than if you recently put on the freshman 15 or are already lean.

Carbohydrate Tolerance

The next factor that I would consider in finding the ideal macronutrient ratio to support your training is your carbohydrate tolerance. This is something that you can discover through experimentation. A careful look at your body type and history will help you make an educated guess about where you fall on the spectrum.

If you are thin; have always had difficulty putting on/keeping on weight; and grew up consuming pasta, bread, pizza, soda, candy, etc. without much consequence on the scale, you probably have a high carb tolerance.

On the other hand, here are some signs that you might have a low carb tolerance:

  • You have a large frame.
  • You have always struggled to lose weight but put it on easily.
  • You have noticed that if you start to eat better, your weight stays stable but does not necessarily go down.

If you fall somewhere in the middle, like I do, you probably do best when you are eating a “goldilocks” amount. When you overeat, it shows. When you undereat, the weight seems to fall off.

Using this self-evaluation, you can determine where your carb intake should be as it relates to your macronutrient ratio.

To highlight the effect carb tolerance has on the ideal fat-carb-protein ratio, I had one client who lost 10lbs in 3 months by decreasing her carb intake and shifting her macronutrients towards protein and fat while holding her calories constant.

Effect of Exercise on CrossFit Macro Ratio

The last factor to consider is the type of training you do.

If you are a full-time athlete, your focus should be on eating to recover for your next training session. This usually involves a ton of carbohydrate and protein, and a little bit less fat as a percent of total calories.

Unfortunately, even with a high training volume, you may not achieve the body composition you desire. You can see the variation in body composition at the CrossFit Games. Take Chris Spealler (left) and Jason Khalipa (right) for example.

Jason Khalipa and Chris Spealler will have different macro ratios for CrossFit performance

Spealler is probably VERY carb tolerant whereas Khalipa would probably have a spare tire if it weren’t for his 20+ hour weeks spent in the gym and careful monitoring of his food.

If you are like the bulk of the CrossFit population, however, you probably do not train more than 5 hours per week. So what should you do?

Some misguided folks will aim to mimic the top athletes. In this case, unless you have high carb tolerance, you will be consuming far too many carbohydrates and far too few vegetables and healthy fats. This will lead to chronically high insulin concentrations and low sex hormones which will also make it difficult to lose weight.

Alternatively, something I see all too often is athletes who subscribe to a “hardcore” paleo diet that is too low in carbohydrates.

This approach will cause an elevation in cortisol, a stress hormone, in addition to the chronically elevated cortisol from the stress of life, and consistent stimulant (pre-workout, coffee) use. This is a recipe for adrenal fatigue, will make it harder to lose weight AND can cause your progress to plateau.

I have seen this firsthand during a 3-month n=1 self-experiment. I started on a diet with a moderate macronutrient split before testing a hardcore paleo approach which dropped my carbohydrates to about 15% of total calories (from 40%).

The effect? I experienced a 3-month plateau in my lifting, and my resting metabolic rate dropped by 600 calories! I also saw my testosterone move south. You could call it a failed experiment, but I learned from it, so I consider it a success.

How to Calculate Your Macronutrient Ratio for CrossFit

Although I cannot tell you the perfect macronutrient diet plan for all CrossFit athletes and performance-seekers, I can give you a guide that will help you calculate your initial calories and macronutrients for CrossFit. I will also give you some advice for how to adjust your macros as your goals and body start to change.

Just CLICK HERE to download your free guide to calculating macros for CrossFit.

Next, you should start by tracking your food intake for a week. Make this a typical week; don’t adjust what you’re eating just because you have to log it!

After keeping a journal, observe your current calorie intake and macronutrient ratios. Is there a trend? How much protein are you eating? How much carbohydrate? Fat?

Finally, ask yourself, have I been making OR have I ever made progress towards my goals eating this way?

  1. If you are making progress towards your goals, you might not want to change anything!
  2. If you were making progress and have hit a plateau, look at your calories, macros, and other factors like your training and recovery.
  3. If you are not making progress, are you eating at least 0.82 grams of protein per pound of bodyweight?
    • If not, experiment by eating at least 0.82g of of protein per pound of bodyweight.

It can be hard to make the lifestyle changes necessary to achieve your ideal macronutrient ratio! There are also numerous other factors that play into your ability to make progress towards and reach goals- from nutrient timing to programming.

Click Here to download your free guide to calculating your macros for CrossFit.


  1. Berardi, John. The Essentials of Sport and Exercise Nutrition. 2nd ed. N.p.: Precision Nutrition, 2013. Print.
  2. Ivy, John, and Robert Portman. Nutrient Timing: The Future of Sports Nutrition. Laguna Beach, CA: Basic Health Publications, 2004. Print.
  3. Phillips, Stuart M., and Luc J.c. Van Loon. “Dietary Protein for Athletes: From Requirements to Optimum Adaptation.” Journal of Sports Sciences 29.Sup1 (2011): n. pag. Web.