As we said in our CrossFit workouts article, and as we generally preach… You can’t expect a system to work optimally without fueling it properly.
You may consider that to be a car, an industrial machine or just about any other system, but in this case, we’re talking about the human body.
In the above-mentioned article, we went in-depth and talked about the nature, ideology and specialization of the CrossFit workouts, which have become popular in recent years.
In this article, we will talk and give you advice about how you can approach your nutrition, if your main form of training is CrossFit.
Alright, in the CF Workouts article, we came to the conclusion that CrossFit has a main goal of creating the perfect athlete.
Not an athlete that is best in one particular discipline, but rather an overall well-developed athlete, that has pretty much all-around development, made even.
That means the CF athlete is strong, has high stamina, explosiveness, accuracy, agility, dexterity, etcetera.
Now, while that is true, CrossFit has one particular trait that sticks out, as opposed to regular training.
And that is namely, the rest times.
With CrossFit, you will see high intensity of effort, with little to none rest.
There’s a common term used amongst CrossFitters and that is the term “Time attack”.
As much work done in as little time as possible.
From all of this information, we can conclude that to a high degree, CrossFit training requires endurance.
Now, before we tell you what, how and when to eat if you want to optimize your CF workouts, let’s have a look at the energy systems of the body and the type of fuel they use.
Energy systems of the body
“The reason that we eat, besides the fact that food can be so delicious, is for energy and building blocks. Metabolism revised- Colby.edu” 1
Logically, as a closed biological system, the human body needs to ensure energy for physical demands of any intensity and duration.
To do so, the body utilizes the 3 main energy systems – Instant Anaerobic, Anaerobic-Lactic and last but not least, Aerobic.
We know that for some of you, those terms may be confusing so let’s define what Anaerobic, aerobic and lactic mean.
Aerobic and anaerobic
To put it simply, aerobic processes are energy-releasing processes in the body, that require oxygen to release energy, hence, aerobic.
On the flipside, we have the anaerobic processes, which have the same function- Releasing energy.
However, these energy-releasing processes, DO NOT require oxygen to function, and hence, their name- Anaerobic.
For decades, sports academies and many scientific books and journals have taught us that lactic acid is the root of all evil when it comes to exercise fatigue.
However, recent studies actually PROVE that lactic acid is not guilty of muscle fatigue, but is actually a buffer and a source of energy for physical activity
So, now you might be asking- Well, then, what causes muscle fatigue if it’s not lactic acid?
Well, keep reading and you will find out!
Adenosine triphosphate, adenosine diphosphate & creatine phosphate
Each and every living being on this planet, be it a plant or an animal, needs energy to function.
Adenosine triphosphate, shortly ATP is the molecular energy currency that all living beings use, to complete each and every motion.
That is to say that ALL 3 SYSTEMS, have one goal- Regenerating ATP.
Even the slightest moves of my fingers, while I'm writing this article, involve the use of ATP.
ATP is the single most potent source of biological energy and in cases of sudden or extreme intensity, it grants our muscles INSTANT energy to function.
However, even though it is extremely powerful, the supplies of it are relatively small and it can sustain energy support for no more than 3-5 seconds.
When the ATP stores of the body are depleted, we get the byproduct of ATP which is Adenosine diphosphate- ADP.
Then, in order to regenerate ATP, the body joints a phosphate molecule from Creatine phosphate- CP and regenerates ATP for another 5-10 seconds of intense physical activity.
The instant-anaerobic energy system
Alright, now that we have some basic terms defined, let’s start with the first, most-powerful energy system of the body.
The instant-anaerobic system is an energy system that DOES NOT require oxygen to function, hence its name- Anaerobic.
This system grants energy momentarily to sustain HIGH-INTENSITY physical activities.
Logically, the system’s main sources of fuel are the ATP and CP reserves.
Again, during the first couple of seconds, we observe a depletion of ATP, then it gets regenerated via the body’s secondary fuel reserve- Creatine phosphate, which joins ADP to regenerate ATP.
This system supports HIGH-INTENSITY physical activities for SHORT DURATION (5-10 sec)
A perfect example here would be a 60-meter sprint or a 6-repetition max bench press.
Why bold high intensity? In CrossFit, we observe high intensity of EFFORT, not high intensity of the WORKLOAD.
That is to say that this energy system grants energy for movements that are closer to the top end of your MAXIMUM STRENGTH CAPABILITIES, rather than the speed at which you’re doing work.
To sum it up- The ATP & CP energy system uses ATP & CP to sustain high-intensity physical activities that last up to 10 seconds.
This system is the QUICKEST to regenerate ATP, in terms of molecules of ATP per minute of time.
However, it is the least sustainable one, as it can do so for short periods of time.
The anaerobic-lactic energy system
Alright, we’re past the 10 second mark, now the body starts using Glycogen to regenerate ATP, in a process called “Glycolysis”.
Essentially, glycogen is the stored form of glucose, which is the end product of carbohydrate metabolism.
Glycogen is stored in the muscles for the most part, and a smaller part is stored in the liver.
The anaerobic-lactic energy system is quite logically a system that DOES NOT require oxygen to release energy (anaerobic) and produces lactic acid (lactic).
As I said, past the 10 second mark, the body starts breaking down glycogen to regenerate ATP and at about the 30th second, that breakdown of glycogen leads up to an accumulation of lactic acid.
HOWEVER! Lactic acid is NOT guilty of the muscle burn, otherwise called acidosis (lactic acidosis).
Note- Technically, lactic acid is NOT produced in the body, but for the sake of common knowledge amongst trainees, we will keep using this term. The correct term is lactate.
What happens is this- The breakdown of ATP, CP and glycogen, leads to an accumulation of protons (Hydrogen ions), which are what ACTUALLY causes the burn.
As glycogen breakdown advances, the body also accumulates pyruvate, along with the protons.
Somehow, the body needs to adapt and neutralize this painful build-up and in order to do that, it starts releasing lactic acid.
That is to say that lactic acid acts as a BUFFER to the muscle acidosis and is not the actual cause.
Furthermore, past the 90 second mark, lactate gets back into the energy cycle and actually gets USED for energy.
Bottom line – The anaerobic-lactic system sustains MODERATE INTENSITY physical activities, lasting up to 2 minutes- Moderate duration. A perfect example here is a 400m sprint
This system breaks down Muscle glycogen to regenerate ATP and in doing so, stacks lactic acid, which in turn buffers the painful build-up of protons, caused by ATP, CP and glycogen breakdown.
This system is the second-quickest to regenerate ATP, in terms of molecules per second, however, it is still not sustainable, as it does so for only up to 90-120 seconds.
“In order to neutralize the soaring accumulation of pyruvate and protons (from the splitting of ATP), each pyruvate molecule absorbs two protons into its structure, converting to lactate.
Thus, lactate production is ACTUALLY A CONSEQUENCE of cellular acidosis and NOT the cause of the acidosis. Lactate: Not Guilty as Charged Len Kravitz, Ph.D. 2
Aerobic energy system
You’ve heard it, you’ve seen it on the TV: Aerobics! Aerobic exercises, aerobic workouts, etc.
W-what does it mean?
Well, here’s what it is…
… Aerobic exercise simply engages the aerobic energy system.
This energy system, logically, requires oxygen to release energy (aerobic) and can do so for HOURS. The body starts utilizing the aerobic system past the 2-3-minute mark of physical activity.
The aerobic energy system uses muscle and liver glycogen as well as fats to regenerate ATP.
The last resort energy substance of the aerobic system are proteins, but that is only if glycogen and fats are NOT available.
With the aerobic system, we sustain LOW-INTENSITY physical activity that is LONG in duration.
And by long, we mean HOURS. A perfect example here would be a cross-marathon.
Note: The aerobic energy system is the LEAST POWERFUL and slowest to regenerate ATP, however as we said, it can do so for HOURS.
Why do I need to know all of this?
If you want to know how to use a machine or a system, you better know how it functions.
Let’s sum it up:
ATP is the molecular energy currency of all living beings.
As humans, we have 3 energy systems to help us regenerate ATP and all 3, do so in different manner, with different substances.
The instant-anaerobic energy system sustains high-intensity physical activity, using ATP and CP reserves.
Following up is the anaerobic-lactic system which uses muscle glycogen to regenerate ATP and furthermore, lactic acid in a mixed aerobic-anaerobic metabolism.
Lastly, we start using the aerobic energy system which utilizes muscle and liver glycogen, along with fatty acids and proteins if glycogen and fats are not present.
Which systems does CrossFit utilize?
Knowing all of the above is a crucial part. Now we can analyze and see how the body adapts to the CF workouts. So, let’s do it.
We can say that in the beginning of a CF workout, we use the immediate (ATP & CP) systems.
However, as the workouts advance, the intensity decreases and the rest times get lower, we switch to a rather mixed anaerobic-aerobic energy metabolism, where we mostly use Glycogen & fats.
So, there you have it! To tell you how you should eat for CF training, I didn’t have to talk about nutrition specifically, more so than how the body uses nutrition to grant energy.
The answer here is – Your nutrition should include high carbs and moderate fats, along with the mandatory protein for muscle recovery.
Before we get into specific foods, let’s first discuss how to calculate your INDIVIDUAL needs.
Calculating individual nutrition needs
Quite logically, we all have different needs, simply because everyone is of a different age, gender, height, weight and has different levels of physical activity and goals.
Now, all those variables are widely combined in calculators that give an approximation of your Total daily energy expenditure (TDEE).
Shortly, TDEE is the amount of energy (calories) that your body needs to maintain its weight and sustain a healthy inner environment, based on the variables above.
If you’re consuming less than the TDEE, you will lose weight, if you’re consuming more, you will gain weight, and if you are consuming equal, you will maintain.
Now, we won’t give you any complex formulas, but a simple one- To approximately calculate your TDEE, take your weight in pounds and multiply by 15.
Experiment with the calories and monitor yourself, until you reach a state of weight maintenance, so that you know how many calories you need to maintain your weight (actual TDEE)
Note: Monitoring is done by weighing yourself IN THE MORNING on an empty stomach before breakfast, AFTER going to the toilet. This is your true weight.
Do this every Sunday and decrease or increase calories as needed, until you manage to maintain weight for 2 weeks in a row.
Note 2: Weight fluctuations are normal, don’t stress out.
With CrossFit training, we highly recommend avoiding or minimizing a deficit, where you consume less than your TDEE.
Bottom line is 200-300 calories below TDEE if you want to lose weight.
What about protein, fats and carbs ratios?
Now that you know your TDEE, it is time to split it into macronutrients at proper ratios.
As we already know, the body’s preferred energy substances are glycogen and fats, which is exactly why a ketogenic diet would be complete nonsense in this case.
Yes, the body can use the fat for energy, but the muscles will look flat and depleted, as glycogen keeps them full and healthy.
We preach the balanced, diverse approach to nutrition.
And so, to calculate your protein needs, simply consume 1 gram of protein per lbs. of bodyweight.
This should be your protein consumption, whether you are in a deficit, maintenance or a surplus.
Keep in mind that protein and carbs have a caloric value of 4 calories per gram, while fat is more than 2x, at 9 calories per gram.
We recommend a slight/moderate surplus for trainees that do not have excessive fat accumulated.
The fat intake then, is 0,45-50 g per lbs. of bodyweight. And so, a 170 lbs. individual would be right about 75-85 grams of fats.
The rest is carbohydrates.
So, if a 170 lbs. individual needs approximately 2550 calories to maintain their weight (170×15), that would be 170g (*4=680 calories) of protein and 75 grams of fat (*9=675 calories).
With this simple calculation we have a total of 680+675=1355 calories from proteins and fats respectively and we’re left with 2550-1355=1195 calories for carbohydrates.
To calculate the amount, we simply divide 1195:4=298 grams of carbohydrates.
Once we calculate the maintenance calories and know them for sure, we determine goals and work with the calories accordingly.
We highly recommend that you EXPERIMENT with different ratios of carbs and fat, as there are general guidelines and physiological principles at which the body works.
BUT! Everybody will feel different at different macronutrient ratios and everybody will be able to sustain a different approach to nutrition, so find your golden environment.
Yes, for the most part it is calories in VS calories out that will determine how your weight changes.
However, if you want quality workouts, you need quality fuel, meaning, quality food sources.
Below, we will give you our top recommendations for protein, carbs and fat sources.
- Chicken meat
- Beef meat – Steak, ground beef, patties, etc.
- Fish (perfect night protein, pretty light and easily digestible)
- Dairy products (Cheese, yoghurt, etc.)
Plant protein sources
For all of you vegetarians and vegans reading this- We are not forgetting you!
- Whole grain bread
- Vegan protein powders
Pre-workout complex carbs
These are carbohydrates with more complex chains that grant the organism a slow, constant stream of energy as they take longer to get metabolized and converted into glucose and glycogen
- White rice
- Brown rice
- Beans (red, white, colorful, mixed, green)
- Whole grain bread
- Sweet potatoes
- Regular potatoes
Post-workout simple carbs
These are easily-digestible, fast-metabolizing carbs that quickly replenish energy reserves after a workout.
- Dark chocolate
Generally, any fruit/simple sugar. Don’t binge on chocolate though.
I'd have success with fruits as they have simple sugars BUT also fibers, which will give you a feeling of satiety, as opposed to processed sweets.
For the most part, if you are an omnivore, you will get your fats from meat and animal products as a whole.
However, here are some other sources as well, which might suit vegetarians and vegans as well.
- Olive oil
- Fatty milk
- Yellow cheese
- Coconut oil
- Nut butter
- Flax seed
When and what to eat?
Proper nutrition is no rocket science, really. There are general rules that need to be followed, and as long as you do so, you’re good to go.
- Don’t eat shortly before a workout
You want your body to be fueled and ready for the workout. If you put your body in digestion mode during the workout, the performance will be sub-optimal.
First, because your blood is going to your stomach and second, because the food (energy) is not metabolized yet.
We highly recommend eating at least 60 minutes before a workout. Ultimately, 90-120 minutes is best.
The pre-workout meal should consist of more carbohydrates and less protein, while the post-workout meal should consist of more protein and less carbohydrates.
- Complex carbs
You need sustainable fuel for your workouts, which is where complex, slow-digestible carbs like rice and oats come into play.
We highly recommend consuming those before workouts or intense physical activities.
Simple sugars such as white sugar or fructose (Fruit sugar), can be consumed after a workout.
- Dinner time
Sleeping is a big part of optimal recovery, while in delta brain waves state (deep sleep) the body rejuvenates and recovers.
Again, you don’t want to interrupt the deep-recovery with digestion, which is why your dinner should be 2-3 hours before you fall asleep.
Carbs at dinner?
Yes, that is fine! Especially if you have demanding physical activity in the morning.
We generally recommend eggs & meat for dinner, along with leafy, light vegetables.
CrossFit training is a complex type of physical training that targets the development of nearly all physical properties of the human body.
In being such a demanding activity, it implies that the endurance of the individual should be highly developed.
In order to stimulate a positive adaptation, in which the individual achieves progressively higher levels of strength, strength endurance and aerobic endurance, proper nutrition is a must.
The main energy systems that CF training utilizes are the Anaerobic-Lactic and Aerobic, which use muscle and liver glycogen, along with fat, to grant ATP regeneration and sustain activity.
Logically, knowing this, we have to focus on quality carbohydrate sources, along with good amounts of fat.
Protein intake is fixed at 1 gram per lbs. of bodyweight, while fat is fixed at 0,45 to 0,5 grams per lbs. of bodyweight.
The remaining calories go for carbohydrates.
Diverse and balanced nutrition is recommended, as no extremes are considered healthy- Be it extreme deficits or simply, reducing a macronutrient to almost 0, like the ketogenic diet does.
If you are an omnivore, we recommend a good amount of animal products, along with grains, fish and vegetables. For plant-based individuals, mixing different types of seeds and legumes is mandatory.
Hitting your daily calorie goals and properly fueling your biological system for the demands of CrossFit training is a MUST, if you want to achieve consistent results.
Wanna read our complete Crossfit workout report? View it here!