Whilst carbohydrate may be the first thing discussed when talking about endurance exercise, protein is often a close second. It often causes great debates as there are a lot of myths going around about type, how much, and when to have protein.

The topic of protein comes up a lot in my 1:1 consultations with endurance athletes. If you're concerned about your protein intake and would like some expert advice, personalised to you and your goals, book a free 15 minute call here to discuss your needs.

Let’s delve into what protein is and whether there's any benefit to having sports products (including protein powders), or whether you should be focusing on food.

What is protein?

Firstly, it is important to understand what protein is, and why it is important. Proteins are chains of amino acids. Protein is in all living cells and accounts for around 15-20% of total body mass. About half of this is in skeletal muscle, but protein is also involved in a lot of other tissues including bone, cartilage, skin and bloods. It also has functional properties in building hormones and enzymes.

There are 9 essential amino acids which we must acquire from our diet and 11 non-essential which our bodies can synthesise. Protein helps to stimulate muscle protein synthesis, which is why it is so important in general but particularly also alongside exercise.

How much protein do you need for exercise?

Daily requirements depend on body weight, exercise type and intensity and also your performance goals. Therefore, make sure you are following a requirement that is individualised to you, rather than a generic number. This can generally range from anywhere between 1.2-2.2g protein/kg body weight.

Whilst generally most people hit their daily requirements for protein from diet alone, there are some tweaks we can make to optimise this. You should consider timing and distribution across the day as well as the quality of protein choice. But remember, more protein isn’t necessarily better. By eating more protein than you need, you tend to then not be eating sufficient carbohydrate which will limit your training and energy levels.

What is the best way to take protein?

Food protein sources can be split into animal and non-animal sources. It was previously thought that following a vegetarian or vegan diet meant that you could not get enough good quality protein. However, with a little planning this has largely been debunked.

Most plant-based sources of protein are incomplete sources of protein (i.e., lack at least one of the essential amino acids), with the exception of soy and quinoa. But by combining your sources of protein you can overcome this issue. For example by combining hummus or peanut butter with wholegrain bread, or having oats with seeds/nuts this can lead to a complete protein source.

Animal sources of protein include meat, fish and dairy products, these are all complete and high quality protein.

What does 20g of protein look like?

Each of these provide 20g of protein:

• 1 pint cows milk

• 250g chickpeas

• 80g tuna

• 200g natural yoghurt

• 3 eggs

• 75g peanut butter

• 80g cheddar cheese

Protein powders

There is no standard formulation for protein powders. They tend to be made from one or more types of protein, isolated from food, then concentrated into a dried and powdered form. They can come from either an animal source, including whey or casein, or from plant sources including soy, pea and hemp. Generally, a serving is one scoop, which provides between 20-25g of protein. 

Types of protein powders:

Type of protein powder	Pros	Cons
Whey Protein Isolate	Gold standard – promotes muscle protein synthesis. High biological value	Minimal carbs and fats
Whey Protein Concentrate	Similar to whey protein isolate. More carbs and fats. Cheapest option	More expensive
Casein	Potential benefits when consumed prior to sleep. Slow-release protein	Not ideal to use post workout/exercise
Soy	Promotes muscle protein synthesis at a similar rate to whey protein isolate. Plant source	Low in leucine (often supplemented in products though)
Pea & Rice	Benefits when combined and fortified. Plant source	Low in specific individual amino acids when one source

There are some additional considerations to take into account when making decisions about protein products.

Protein powders are unlikely to provide the same feeling of fullness as a meal, so they may leave you feeling hungry. They may also not have all the other nutrients that a food source will provide including calcium.

One really important consideration is the concern about contamination of supplements with other products - if you are competing then ensure that you choose Informed Sport certified supplements to be certain that the product is what it says on the tin.

Protein supplements can also be found in bars, fortified foods and ready to drink products; the information above applies to these as well.

Protein during exercise

Generally protein is less important to consider during exercise, however more recent evidence has led us to reconsider the importance in long duration endurance exercise.

For example in events/training over 10 hours; having 20-30g protein every 4-6 hours is likely to help mitigate some of the damage caused by doing such an activity and helps with recovery.

Timings

The key is ensuring you have sufficient protein across the day, then to consider the timings. Naturally this is often spread out across the day for practical reasons.

Post exercise protein to help optimise recovery is important, especially if you have back to back sessions. Try to get 20-30g protein in alongside a source of carbohydrate within an hour of finishing your session.

Conclusion

As a sports dietitian I would recommend a ‘food first’ philosophy, but we are realistic and know that it is not always possible to get optimal amounts of protein to support your training.

So, therefore I think it is better to think of ‘food first but not food only’. Try to optimise your diet where possible, but if there are gaps then use protein supplements as required!