How to Fuel Correctly in the Lead-Up to a Fitness Competition

There is just over a week to go until the CrossFit Open 2023 kicks off, and by this stage, you’ll be gearing up for the main event and likely have a strict training regime in place. A large amount of focus goes on session plans, mobility work and recovery and rightly so, but nutrition also needs to be at the forefront of your game plan for the weeks ahead.

What is performance nutrition, and why is it important?

Performance nutrition is the use of dietary interventions to influence and enhance sporting performance, training, and ability to recover. As it can help improve athletic performance, it is a vital consideration for those wanting to keep the body performing at peak levels.

Physical activity is extremely demanding on your body. Therefore, you must ensure you are fuelling correctly both beforehand to support performance and afterwards to aid with the recovery process. 

Following a strategically planned diet ensures you are providing yourself with the finest nutrition your body needs to support your training demands.

The importance of macronutrients

Macronutrients are components in our diet which provide us with energy and are required in relatively large quantities (hence the name – macro).

Protein, carbohydrates and fat all have individual responsibilities within the body and specific importance when it comes to sports performance. A diet consisting of a carefully thought-out balance of all three macronutrients will provide your body with all it needs to push through training sessions and optimise progress over time.


Proteins are primarily functional, and structural components within each cell of the body and so are required for growth and repair, as well as the maintenance of optimal health.  

Protein is made up of essential and non-essential amino acids, which are the building blocks of your muscles. Essential amino acids are those which cannot be synthesised by the body and, therefore, must be obtained from food. In their absence, it would be impossible to build, repair or maintain muscle mass.

Active individuals may require in the region of 1.2g – 2.0g per kg of body weight. For highly active people and athletes, this figure can exceed 2.0g per kg of body weight. However, be aware that requirements are highly individual and what works for one person may not for another in similar circumstances.

Protein is constantly built up (muscle protein synthesis) and broken down (muscle protein breakdown) in our bodies, and the balance between the two is called protein turnover. Both processes happen simultaneously. 

MPS is stimulated by 2 main factors: protein intake and resistance training. If combined, the effect is even stronger (Burd, 2009). In terms of timing, the recommendation from the ISSN is to spread the intake across multiple feedings (every 3-4 hours). While more research is being done to establish the effects of this long-term, there doesn’t seem to be any harm in doing so, and it may provide some benefit. If absolute protein intake is optimal, the effects of timing will depend mainly on the measure of your experience as an athlete.

Several studies have found that depending on how experienced someone is, the anabolic window can last up to 48 hours, but the impact diminishes over time (Trommelen, 2019). Research on the impact of trained and untrained muscle has shown a higher increase in MPS in trained muscle as opposed to untrained muscle, but the effect in untrained muscle lasted longer (Tang, 2008). This also means recovery is quicker. Hence the timing of nutrients is more relevant to more experienced athletes. Novice lifters can usually get away with just making sure to cover their absolute needs in a 24-hour time frame, whereas if you’re more experienced, a little more planning should go into your intake. 


Carbohydrates are the body’s preferred fuel source, even more so for the high-intensity training sessions you will be doing. A diet rich in carbohydrates is vital to fuel demanding training sessions and replenish muscle glycogen stores post-workout.

Carbohydrates consumed are metabolised into glucose. Excess glucose is stored in the liver and muscles as glycogen and can be quickly converted back into glucose if required. Glycogen (storage form of glucose) stores within the body are limited, and depletion has been found to negatively impact exercise performance, leading to feelings of fatigue and exhaustion. 

You may be familiar with the feeling when you ‘hit a wall’ and feel as though you can’t give anymore. When levels are extremely low in muscle stores, the body is forced to revert to utilising protein to produce glucose, which can lead to muscle damage and even overtraining if sustained for some time. Depending on how experienced you are, stores can last you anywhere between 90 and 120 minutes.

Carbohydrate timing can be a useful strategy to optimise high-intensity training. Again training makes the muscle more prone to the uptake of dietary nutrients, in this case, carbohydrates. By factoring in carb timing and depleting glycogen stores followed by refuelling, the muscle super-compensates and stores more glycogen than before the stores were depleted. An effect that is called carbohydrate loading. As a result, your muscles can store more carbohydrates, become more efficient using the available carbohydrate and thus perform better over time.


Fat is the third and final macronutrient needed as part of a healthy diet. It is needed as an energy source to provide the body with essential fatty acids (dietary fats that are vital for growth and cell functions but cannot be synthesised by the body), to allow for optimal functioning of nerves and the brain, assist in the production of hormones and are essential for the absorption of vitamins A, D, E and K.

Omega-3 fatty acids are a type of polyunsaturated fat thought to be essential for recovery due to their anti-inflammatory properties. 

Reducing inflammation is important when performing at your peak, as it helps reduce muscle soreness post-training (the dreaded DOMS), allowing you to recover more quickly and be ready to go again in no time!

Effects on performance and body composition seem to be largely unaffected by the timing of fat intake. The metabolization of fat is a slow process, and even though fats play an important role in rebuilding tissues and providing building blocks for anabolic hormones, this does not seem to depend on the timing of ingestion. 

5 factors to consider in the lead-up to the big event

  1. Ensure you are eating enough calories to support your energy output: chances are, you have ramped up your training in the lead-up to the event. As a result, your intake should be altered to reflect this. If you are not eating enough to support your energy output, you will quickly know about it, as your performance will begin to suffer – you’ll fatigue far more quickly and won’t perform at your best.
  1. Don’t forget about your micronutrient intake: A rapid increase in training volume and potentially overtraining can impair immune function over a prolonged period. Therefore, it is important to provide your body with all the goodness it needs in the form of vitamins and minerals to support the normal functioning of your immune system.
  1. Put a little more focus on pre and post workout nutrition: Ensuring you are going into a session adequately fuelled will improve your ability to cope with the specific training load and reach your maximum potential. Eating the correct balance of nutrients after a session is all about recovery. It enables you to get the most out of the session you have completed and allows your body to get back to training within a shorter period of time. This is vital when you are training intensely for a competition.
  1. Make sure you stay hydrated: Dehydration can lead to muscle fatigue, cramping, loss of coordination and decreased energy levels, depending on the degree of percentage body weight change. This translates into a lack of strength in training sessions and impaired progress over time. Aim to drink at least 2-3 litres of water each day, more on training days. 
  1. Ensure you get enough rest: Rest days are just as important as training days when it comes to getting results as they enable the body to recuperate and muscles, tissue, nerves and bones to adapt to the stimulus they have been exposed to, whilst also allowing them to repair and strengthen.

When it comes to performing at the top of your game, it is hugely important not only to put time into your training plan but also your nutrition plan; it could just be the difference between 1st and 2nd place!

If you need a hand or one less thing to think about, get yourself on board with us here at Fresh Fitness Food! Less time shopping, preparing and tidying up equates to more time training and maybe even an extra hour in bed!


Burd, N.A.m Tang, J.E., Moore, D.R. and Phillips, S.M. (2009). Exercise training and protein metabolism: influences of contraction, protein intake and sex-based differences, Journal of Applied Physiology, 106(5), 1692-1701.

Trommelen, J., Betz, M.W. & van Loon, L.J.C. Sports Med (2019). The Muscle Protein Synthetic Response to Meal Ingestion Following Resistance-Type Exercise. Sports Medicine 49: 185.

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Published by Georgia Chilton

In her teenage years, a love of food and rowing led Georgia into this field as she wanted to know how to optimise performance through nutrition. With a BSc in Nutrition and an MSc in Sports and Exercise Nutrition, she has the skill set to help you track towards your goals and maximise your potential.

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