How Much Protein Do Cyclists Actually Need?

A pretty hot topic this one! 

As we’ve covered in a previous blog (Protein For Training Adaptations), as a cyclist’s protein intake is a key component of your diet for helping to maximise training adaptations and support the growth of new muscle tissues, which ultimately helps us rebuild post-exercise into stronger, better athletes with more performance.

Protein is the single most important macronutrient within our diets as cyclists.

From the individual muscle fibres that contract and turn the pedals to the mitochondria, which are the engine of the muscle cells, to the capillaries, which supply the muscles with oxygen and glucose, and the haemoglobin, which carries oxygen to the muscles, these key components of our physiology are all largely made up of protein.

Protein also plays a key role in building the cells within our immune system that help us fight off illness and infection.

Consuming adequate dietary protein is, therefore, essential to ensure that we have the building blocks available to build more of these organs and develop into better riders able to produce more watts.

The protein we eat in the diet not only plays a key role in providing the amino acids that are the building blocks for growth and repair, but the essential amino acid leucine also acts as the trigger for switching on muscle protein synthesis, the process through which new muscle tissue is created.

The World Health Organisation recommends a daily intake of 0.8 grams of protein per kilogram of body weight. However, this value is designed to prevent deficiencies within the diet of largely sedentary individuals rather than optimise the adaptive response to training, which is what most cyclists will be far more interested in.

It’s also a value that has been argued as being too low, even for the general population (https://pubmed.ncbi.nlm.nih.gov/26960445/).

As such, cyclists tend to have a greater requirement for protein. This is largely driven by the increase in protein breakdown that occurs whilst riding. Protein is often broken down and used as a fuel, accounting for as much as 5-10% of energy expenditure during exercise. There is also a heightened requirement to help support repair and recovery.

The optimal amount of protein a cyclist should eat depends on several factors, but the typical range is between 1.2 grams per kilogram of body weight and up to 2.2 grams per kilogram of body weight.

An athlete's daily energy expenditure is one of the key factors in determining where to aim for this range. Typically, cyclists can have high levels of energy expenditure during heavy training, which can result in large energy requirements. There is also a larger breakdown of protein during exercise, w can mean requirements are going to be higher, i.e. towards the top end of the scale at 2 grams per kilogram body weight per day.

It's often relatively easy for an endurance athlete to hit high protein intakes simply as a result of eating a large volume of food. I’ve often seen cyclists with heavy training loads easily eat in excess of 3 grams of protein per kilogram body weight, well in excess of an intake that is shown to be beneficial in scientific research. 

In contrast, during times of lower training need, too heavy a focus on protein-rich foods can displace other macronutrients, particularly carbohydrates, negatively impacting performance.

When energy expenditure is low, there is less of a requirement for protein and aiming more towards the lower end of the scale (i.e. around 1.2 grams of protein per kilogram body weight) would make sense.

Cyclists often spend time looking to optimise their body composition by creating a calorie deficit to drive fat loss. Being in a kcal deficit can drive more protein (i.e. muscle protein) breakdown.

A key strategy during fat loss to maintain muscle mass (and performance) is to optimise protein intake alongside training to help maximise muscle growth and offset any losses. Here, as much as 2.2 grams of protein per kilogram of body weight per day may be beneficial to help maintain muscle and drive fat loss.  

As a general rule, when looking to maximising the gains in muscle strength and size, there appears to be little benefit to exceeding around 1.6 grams of protein per kilogram during resistance exercise programs, as shown in this meta-analysis of nearly 50 studies with close to 2000 participants (Protein for muscle mass gains - meta analysis) 

 Does protein timing and quality matter? We’ll cover this in more detail in a future blog, but in effect, protein quality doesn’t appear to matter when consuming 1.6 grams per kg body weight per day. Whilst some sources of protein have a lower quality, if we consume enough of them, we can offset this. 

In terms of timing, we’ve covered this in detail with the latest up-date research in a previous blog post that you can find here (Does protein timing matter?) 

- Coach Ben