How to improve performance with nutrition

nutrition performance

As is often said in the world of fitness, muscles are made in the kitchen.

The Progrm can provide you with one of the best training programs in the world however training is optimised by the right diet to help your body refuel and recover.

But what does it mean to eat well and how do you know if you’re doing it right?

That depends on many factors including your age, height, weight, goals and activity levels as well as the type of exercise you do and the eating style you prefer.

In this article we’ll explore how you can adjust your diet to optimize your athletic performance and ensure you’re performing at your very best.

How much to eat

If you don’t already track what you’re eating, it’s a good place to start to find out how many calories per day you’re currently having and how much of those are fat, protein and carbohydrates, otherwise known as macronutrients.

crossfit nutrition

What is the easiest way to count calories?

– To get some precise measurements, you can log what you’re eating in an app such as MyFitnessPal with a database of over 2 million foods which can be typed in or scanned via barcode.
– Choose how much of that food you’ve eaten, for example 100g brown rice, and it will tell you the calories and macronutrients in that food.
– If you track this for a week you’ll get an idea of roughly how many calories you’re eating per day on average.

Now, how do you know if you’re eating the right amount of food?

This is where the magic happens.

To calculate what you should be eating to achieve your goal, there’s a few factors which need to be considered including:

  • Age
  • Biological sex
  • Weight
  • Height
  • Hours and intensity of exercise per week
  • Goal (build muscle, improve performance etc.)

The factors which have the greatest effect on the number of calories you need to consume are the intensity and frequency of exercise, as well as your goal and your biological sex.

If you are a CrossFit athlete training 6 times a week at least 4 hours a day, your needs will be very different to someone with a desk job who takes an occasional walk, or even to someone training for a marathon.

It’s no secret that the more active you are, the more you need to consume to maintain your activity levels, but adjusting how these calories are split can have some interesting effects on the body and your performance (See adjusting your macro ratios).

Your goal will also impact how much you need to be eating.

Are you training to build muscle, to shred body fat or to optimize your athletic performance?

Each of these means an adjustment to your nutritional needs and is included in the calculations. In terms of your biological sex, women need fewer calories than men and they also burn fat more easily.

Adjusting your macro ratios

The amount of calories you consume in comparison to your activity levels is what determines if you lose weight, gain weight or maintain your current weight.

This is because…

No matter what you eat, if you eat more calories than you burn, you will gain weight and if you eat fewer calories than you burn, you will lose weight.

However, our bodies function best if we have a balance of carbohydrates, protein and fat according to our particular training needs.

A good place to start is 35% carbs, 30% protein and 35% fat if you are exercising regularly and not intensely.

For athletes, it can be beneficial to change your macro ratios according to the type of training that you do.

Endurance athletes will need to rely on all of their macros at different points of their training, but carbs are extremely important as they are converted to energy quickly and are excellent for fuelling workouts.

Fat is also used by endurance athletes more so than strength trainers as they exercise at low to moderate intensity which is fuelled by fat since your body can take in enough oxygen at this intensity to convert the fat to energy.

For strength trainers, carbohydrates are equally as important as for endurance athletes, especially for those training at high intensity.

High-protein diets have also proven to be effective in improving performance as protein enhances muscle growth and limits the degradation and damage that occurs from exercise.

All macronutrients can be used as an energy source if necessary, but protein is the only macronutrient that repairs muscle. Therefore, without enough carbs in the diet, protein could be used for fuel instead which stops it from doing its job of growth and repair.

A recommended starting point is to consume 40% carbohydrates, 30% fat and 30% protein. However, it may be worth experimenting with the exact quantities of macros to figure out the best balance for you.

What is a ketogenic diet?

A ketogenic diet is a very low-carb, high-fat diet, with around 70% of your daily calories coming from fat sources. It’s focussed on consuming whole foods such as meat, fish, eggs, butter, nuts, healthy oils, avocados and plenty of low-carb veggies.

There are many benefits to the keto diet including lowering the risk of some cancers. Most people that choose to follow the ketogenic diet do so because they want to lose weight. The idea is that the body begins to use fat as fuel instead of carbohydrates, so it helps you to lose body fat.

In the world of athletes, there is much debate about how good this is for you.

Most sources suggest that a low-carb diet is not ideal for endurance athletes as they perform best with high levels of carbohydrate which help turn protein into muscle.

However, some studies suggest that after a long period of adaptation (this can take several months), there are benefits to fuelling your body this way for performance in endurance athletes, but not for athletes training in high-intensity, short-duration sports.

Whilst the debate continues in this field, what is clear is that unless properly adapted to, a ketogenic diet can be harmful to your performance, in which case athletes would benefit from sticking to a more balanced split of fat, protein and carbs.

What to eat

Now that you’ve calculated the amount of calories you need per day and split that into macronutrients, it’s time to look at what exactly you can eat to hit those targets.

Does it matter if your carbs come from a donut or a potato?

Should your protein come from meat?

Let’s take a look.


For years, carbs have had a bad reputation for causing weight gain, but for athletes they are essential fuel for training.

Carbohydrates are converted into muscle glycogen which gives you the energy to keep moving.

nutrition for crossfit

But not all carbs are created equal; some are released quickly into the bloodstream, giving you a quick boost of energy, whilst others are released slowly.

Examples of fast-digesting carbs are:

Fruits: bananas, dates, peaches, grapes and vegetables such as pumpkin, green peas, and yams.
Grains: white rice and cereals such as bran flakes will give you a quick boost of energy too.

This type of carbohydrate can be very useful to athletes right after a workout as they need to quickly replenish their energy.

Slow-digesting carbs include:

Wholegrains, legumes such as red kidney beans or lentils and nut butters with no added sugars.

In general, it is good to fill your diet with mainly these types of carbohydrates because they don’t cause spikes in blood sugars like the fast-releasing carbs, and they help you to feel fuller for longer as they release energy throughout the day and they increase fat metabolism.

As well as how quickly they are digested, it’s important to consider the nutrients that different carbs can provide you with.

For example, a chocolate bar can provide you with sugar and some fat, but it doesn’t contain any vitamins or minerals, otherwise known as micronutrients.

Whole Grains and veg are loaded with these micronutrients which are vital for helping you to strengthen your immune system and they are also vital to helping your body build tissue and muscle with the help of your macronutrients.

So choose your carbs wisely and get the most out of them!

Examples of carbs which are minimally processed and contain fiber and micronutrients include:

  • Beans and lentils
  • Quinoa
  • Fruit
  • Potatoes
  • Buckwheat
  • Yuca
  • Whole grain breads and pasta


As we’ve mentioned, protein is essential for growth and repair.

How can you choose the best sources of protein?

This depends on your preferences but protein can be found in both plant and animal sources in varying amounts.

For meat-eaters here are some examples of lean and minimally processed sources of protein:

  • Chicken
  • Turkey
  • Lean beef
  • Lean pork
  • Wild game
  • Fish
  • Shellfish

For those who don’t eat meat or fish, these are great sources of protein:

vegan protein
  • Egg whites
  • Plain greek yoghurt
  • Tempeh
  • Tofu
  • Beans and lentils
  • Protein powders
  • Cottage cheese


Over the years, fat has been perceived as a macronutrient that should be avoided where possible to avoid obesity and lower the risk of heart disease.

For years, low-fat products were everywhere and people were encouraged to cut out fat where possible.

However, the truth is not all fat is bad, in fact we need some fats to build our cells, absorb vitamins and heal wounds.

nutrition program crossfit

The challenge is to eat the right types of fat in the right amounts.

Sources of healthy fats include:

  • Extra virgin olive oil
  • Avocado and avocado oil
  • Walnut oil
  • Cashews
  • Sees (chia, flaxseed, pumpkin, sesame)
  • Nuts: almonds, cashews, pistachios, brazil nuts,
  • Olives
  • Nut butters

In addition to these sources, there are two types of fat which cannot be created by the body and therefore need to be included in your diet.

These are omega-6 and omega-3.

Omega-6 comes from sources such as nuts, sunflowers and rapeseed oil, whereas omega-3 only comes from fish.

Most people have a high ratio of omega-6: omega-3 in their diet but research has shown that we need a much more balanced amount of both fats. If you don’t eat fish, you can take an omega-3 supplement to help you include this in your diet.

When to eat

One of the common questions from athletes or those who are training regularly is should I change when I eat?

Does nutrient timing make a difference to my performance?

I would suggest that nutrient timing is one of the last things to consider.

It’s much more important to ensure you’re consuming your recommended daily intake for your needs and ensuring that your food sources are whole foods or minimally processed where possible.

If you’re consistently getting your macros right, only then would I suggest looking at nutrient timing as that’s when you will notice a difference.

However, many studies have shown that eating around your workouts can have a positive impact on your performance.

It’s commonly advised that you consume a mixture of protein and carbohydrates after a workout in order to repair and grow muscles and replenish energy used.

To fuel your workouts, I would also advise eating a small meal about 1.5-2 hours before your training session which should contain both carbs and protein.

It’s also essential to hydrate yourself before, during and after the workout.

For a high intensity workout you may need up to 600ml water after your workout with electrolytes as well as about 240ml before and during training.


In summary, the best way to improve your performance with nutrition is to make sure you’re hitting your calorie and macro targets every day, eat whole or minimally processed foods where possible, stay hydrated and if necessary, change when you eat to fit around your workouts and replenish any lost nutrients.