Today is the final day of the CrossFit Open 2022; a worldwide fitness event in which you can compete against people of your age/region and fitness level, but most importantly, you compete against yourself year after year. The Open isn’t the only competition around, there’s also Hyrox, the Lowlands Throwdown and the Nationals, just to name a few. 

They’re getting more and more popular and one of the main questions I get is how to plan your nutrition on and around these events to ensure you’re able to perform your best every time? Your strategy will depend mainly on the total volume of work you’ll need to perform. An open workout that lasts on average about 10 mins will require much less than a full day of 5 workouts back-to-back.

Game Day Nutrition

What makes Game Day Nutrition different?

Sports nutrition is different from when you’re just eating to maintain health or lose fat. It isn’t about eating healthy. It’s about making sure your body has all the nutrients available to push hard and perform it’s best without puking over your fellow competitors (unless you want to play it that way of course). 

For most people ensuring they don’t overeat and eating enough protein and veggies is what makes normal day-to-day nutrition sufficient. However, when it comes to optimal performance, the question is: are you sure you’re eating enough? And rather than protein, carbohydrate is your main concern because carbs are still king when it comes to performance, despite all the keto crazes going on these days. Particularly on multi-event days. 

To understand why, we need to understand a little bit about how our muscles create energy from food and the difference in storage capacity of carbohydrates and fats.

How much carbohydrate/fat you’ll burn, depends on your exercise intensity 

As you might know, there are 4 macronutrients that we obtain from our food: protein, carbohydrate, fat and alcohol. The 2 main nutrients we use for energy are fats and carbohydrates. However, the energy currency all our cells use is called ATP and each of these macros need to be converted to ATP in order to power every function in your body. Not just muscle contraction but all other bodily processes. Each of these nutrients are metabolised to ATP differently and some processes are more efficient than others. 

Depending on the energy requirements of the body (read: how hard you’re training) your body will utilise one system more so than another. To produce ATP from fat is a very efficient (lots of ATP per gram fat) but a relatively long, and therefore slow process. That’s fine if your body doesn’t require that much, like at rest or when you’re just going about your day to day activities. You will burn mostly fats then to meet your energy needs.

Please note: this does NOT mean you’re losing more fat when training at a low intensity. Burning fat and losing fat aren’t the same thing! Fat loss is a matter of a negative energy balance (eating fewer calories than you burn). You can burn fat all day and not lose any or even gain fat if your intake exceeds what you need. “Fat burning zones” on fitness trackers or cardiomachines do not mean anything.

Things change when you start exercising and your heart rate and energy needs go up. Fat oxidation then cannot provide enough ATP quickly enough so a larger chunk of your energy needs is then supplied by carbohydrates. This is because carbohydrates can be converted into ATP less efficient (fewer ATP per gram carbs), but super quick. You will notice this system at work as a burning sensation in your muscles after doing things like 100 burpees or a 1 min squat hold, because a waste product of this system is lactic acid.

So the higher your energy needs are, the more carbohydrates you’ll use instead of fat. Both systems will work at all times but depending on your energy needs you’ll either burn more carbohydrate or fat. The tipping point at which you’ll use mostly carbohydrate is at about 70% of exercise intensity.

But we can’t store as much carbohydrate as fat..

Our capacity to store carbohydrates is a lot smaller than fat. We can store fats pretty much limitless but we can only store about 2000 kcal or 500 grams of carbs and chances are you’ll burn through more than that if you’re going through multiple events in a day. Or, if you’re a runner or cyclist training for over 90 mins. 

You will notice when you run out of carbs as this is the feeling that many runners and cyclists will recognise as “hitting the wall”. All of a sudden you can no longer keep up the pace as you do not have enough carbohydrate available to fuel your training. You have to slow down and your legs feel heavy. Depending on training status and nutrition status, most athletes will have to keep going for about 90/120 mins continuously, to reach this state.

You can compare carbohydrates to your current account and fats to your savings account. There’s not as much money in your current account (if your saving habits are good) but you can always access this money. The money in your savings account first needs to be transferred to a current account so it’s not as readily available. It takes a little longer but you have a lot more of it in store. 

This is where the difference between everyday and game day nutrition becomes apparent: it’s all about the dose. Most people do not need to worry about this when they’re just doing their workout after a day in the office. If you’ve eaten normally, you’re going to have enough carbs available to  get you through your WOD. It’s different when you’ve got a day where you’re doing intermittent bouts of intensive exercise. 

So what’s the solution?

The key to optimal performance is ensuring carbohydrate availability. There’s 2 things you can do to accomplish that: making sure your stores are filled to the brim when you start (also known as carb loading) and make sure you refuel during the day to make up for any losses.

We can store carbohydrate in our muscles and liver and we store it then as glycogen. Glycogen stored in a muscle can only be used by that muscle, whereas glycogen stored in the liver can travel to fuel other tissues. This is important because as long as you make sure to take the day off training, you can use the day before your competition to eat your carbs and keep your legs up. So how much are we talking?

Carbohydrate requirements for CrossFit/fitness competitions

This is quite a tricky question to answer. Most studies are done for endurance events and recommendations then vary depending on duration of the race. For fitness competitions it’s difficult to quantify duration as you’ll burn a lot less calories on a 1RM snatch than a 30 min AMRAP with burpees, toes-to-bars and assault bike for example. Carbohydrate recommendations for endurance athletes will therefore probably be excessive for fitness competitions.

For most CrossFit or fitness competitions, carbloading anywhere between 4-6 g per kg bodyweight is probably going to do the trick, but the average enthusiast will probably eat close to that. The best way to figure it out is by trying it out and seeing if it makes a difference to your performance. Carbohydrate recommendations are very much subject to personal preference and how much you can stomach, even for endurance athletes. Women can get away with less than men, so the lower end of this spectrum.

On game day you also want to make sure you’re refuelling between events. Typically 30-60 g per hour is a good place to start.

Romijn et al. 1993

Considerations for endurance events

If you’re prepping for an endurance event you want to pay a bit more attention to the details and you’re going to need to aim for more. In the graph endurance trained cyclists were measured whilst riding at different intensities. VO2max is an indication of exercise intensity.

As you can see, by far the largest chunk is provided by stored glycogen at the highest exercise intensity. This is virtually nothing at rest. Glucose from the bloodstream is also a bit elevated here, so making sure you have enough in store is key, especially once muscle glycogen runs out.  

Guidelines for endurance athletes start at the upper end for fitness competitions: 6 g carbohydrate per kg bodyweight for anything up to 90 mins and as much as 10-12 g per kg per day for anything over 90 mins is recommended. To put this into perspective: that’s about 750 – 900 g carbs for a 75 kg man which equates to 3.75 kg sweet potato or 1.15 kg jelly babies. Good luck getting that in. Some practice is therefore also recommended.

The refuelling recommendations for during exercise are also a bit higher depending on the duration. Basically for endurance events of up to 2.5 hrs 30-60 g per hour is fine, for anything over 2.5 hours the recommendations range 60-70 g/hr to pretty much anything you can stomach: up to 90 g per/hr (Vitale et al. 2019). 

As you can imagine getting this much in can be a challenge. Which is why you also need to consider the type of carbohydrate you’re eating. To stick with the above example, it’s a lot easier (but still a challenge) to eat a kg of jelly babies than it is to eat almost 4 times as much sweet potato. Game day nutrition is probably the only instance in which I’d advise less nutrient dense foods for this reason:

Because I can’t push hard on a full stomach.. 

The main issue with game day nutrition is that eating a lot of volume might cause issues with indigestion. You know, the feeling like you’re throwing up during a WOD. Most people can’t push hard with a lot of food in their stomach, so you want to eat as little volume as possible but still providing adequate energy. Most importantly: carbohydrate and you want that carbohydrate to reach your bloodstream as quickly as possible and that’s typically the case with more refined types of carbohydrate such as refined grains like white rice and wheat products and sugary stuff.

This doesn’t mean you should just stock up on refined junk and eat nothing else, but there’s definitely room for that once your basics are covered. It’s the reason nobody chews on spinach and sweet potato to refuel during a race but jelly babies and sugar gels. Fat, fiber and protein all delay the absorption rate of carbohydrates. This is why I recommend swapping wholegrain for refined grains, cut back on veggies and a little on protein and avoid highly fibrous vegetables and starches such as beans and pulses in your meals on game day. Still eat some veggies, but not as much as you normally would. On top of that add some more sugary snacks.

Now of course carbohydrate availability isn’t the only thing that determines how well you’re gonna do. At some point it’s going to be impossible to offset fatigue, no matter how many carbs you’ve got left in store. After all we’re not machines, but it sure is going to stack the odds in your favour. 

Furthermore, make sure that you test your foods. Don’t try anything new on Game Day, make sure your nutrition is stuff you know so it’s stress-free and allows you to focus on the workouts or the race.

Here are some of my Game Day foods that you might want to consider for your Game Day meal prep:

Risotto rice

It’s very very starchy (this is why it’s such a creamy rice) packing 90 g of carbs per 100 grams (most other rice contains about 75) it’s getting you a lot of carbs per volume. This is why this particular type of rice is an excellent choice. Make sure to add plenty of salt to your meals to top up your electrolytes. I usually make one or 2 savoury rice meals as most other foods I’d eat would be sweet-ish and I quite easily get enough of that.

Apple Syrup

I have loved this stuff since I was a kid. I usually have it with blue cheese but on game day you’ll find me carrying around a jar of this with ontbijtkoek: Dutch type of bread that resembles malt loaf a little bit. Digests super quickly and is a great little snack to have 30 mins before go-time that goes well with coffee to raise your spirits if it’s time for event 5 but you’re kinda ready to go home. I can eat this endlessly and not feel full. One slice with apple syrup contains about 30 g quick digesting carbohydrates.

Stroop & ontbijkoek

Jelly babies/wine gums

My teacher at uni was a diabetic and she always carried a bag of jelly babies with her to quickly raise her blood sugar levels in case they’d accidentally dropped too low. This type of candy is almost pure sugar with very few additions which makes that it gets into your blood quickly. Bad news for fat kids with inactive hobbies but great news if you need a boost of energy for your final few miles of your marathon.

Dates and dried mango

Dried fruit isn’t necessarily a great choice due to their high fiber content. But I find it easier to eat these than a whole bag of jelly babies. It’s good to have options but don’t go crazy with these.


Oats are my go to breakfast meal. Especially on Game Day they’re easy to carry around and pack a lot of quickly digesting carbohydrate. Leave out the protein powder and nuts to optimise absorption rate. You can make them savoury or sweet. I’ll usually have them with raisins, cinnamon and mango. 

Toast with jelly or honey

Who doesn’t love a good sandwich? These are also easy to pack and prepare and if you leave out the (peanut)butter pretty much all carbs.


Berg JM, Tymoczko JL, Stryer L. Biochemistry. 5th edition. New York: W H Freeman; 2002. Section 30.4, Fuel Choice During Exercise Is Determined by Intensity and Duration of Activity. Available from:

Burke, L. M., Hawley, J. A., Wong, S. H., & Jeukendrup, A. E. (2011). Carbohydrates for training and competition. Journal of sports sciences, 29(sup1), S17-S27.

Romijn, J. A., Coyle, E. F., Sidossis, L. S., Gastaldelli, A., Horowitz, J. F., Endert, E., & Wolfe, R. R. (1993). Regulation of endogenous fat and carbohydrate metabolism in relation to exercise intensity and duration. American Journal of Physiology-Endocrinology And Metabolism, 265(3), E380-E391.

Vitale, K., & Getzin, A. (2019). Nutrition and supplement update for the endurance athlete: review and recommendations. Nutrients, 11(6), 1289.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *