Protein 101

Last week, I sat down to discuss post-exercise nutrition with Richie Barclay, (Owner, and founder of Focus Foods UK, and PhD candidate) via Instagram Live, and although we covered numerous topics throughout, the majority of the questions that arrived in my inbox, revolved around protein intake, and carbohydrate periodisation, and some of the points that we made and touched on during our chat.

I have previously written broadly on carbohydrate periodisation in a previous blog post, and so felt compelled to follow up with a similar overview of protein intake, and as usual, I’ll be following the structure of busting some common misconceptions, and providing an evidence based overview of what we currently know. As always, hopefully this blog provokes you to reflect on your current nutritional habits and routines, and perhaps may drive some change in the way that you approach your protein intake.

Understanding Protein. Before we dive too deeply into some myth busting and give you some genuinely usable advice, we need to understand some of the fundamental principles that protein impacts. When we think of protein, we think of muscle - which is understandable as muscle contains approximately 40% of total protein in the human body (we’ll get on to muscle protein very shortly). With the rest accounted for in blood proteins, various enzymes, mitochondrial proteins amongst others; we need to understand that protein plays a part in incredibly vital bodily functions, and not just muscle function.

Besides its role in muscle function, protein, (amino acid) oxidation also contributes to energy production, and it has been estimated to contribute up to 15% of energy expenditure whilst in resting conditions. This number decreases however during exercise as fat and carbohydrate use becomes the prominent pathways for energy provision.

Protein(s), consist of amino acids, which form their building blocks. You may have heard of amino acids, and “branch-chained amino acids (or BCAA’s)” are touched on later. Most proteins, such as those that make up your muscle, consist of up to 300 amino acids, bound together by peptide bonds. Of the 20 different amino acids that are normally found in dietary protein, human’s are able to synthesize 11 of them (these are referred to as nonessential amino acids). The other 9, must be derived from the diet which again underlines the importance of adequate and appropriate protein intake.

First things first, we need to understand that muscle protein balance governs long term changes in muscle mass.

Muscle Protein Balance. That said, the reason you clicked on this link, and the reason you’re reading this article, is likely due to an interest in the relationship between protein and muscle. First things first, we need to understand that muscle protein balance governs the long term changes in muscle mass.

Muscle protein balance refers to the undulating relationship between muscle protein synthesis (building) and muscle protein breakdown (degradation). Muscle protein is constantly turning over, and although this turnover occurs quite slowly in comparison to blood proteins, it is constant nonetheless. This is illustrated simply below, as we can see how the body fluctuates between negative and positive protein balance naturally throughout the day, with regular and evenly spaced meals.

Spending more time above the line then, over a long period of time, in line with resistance training exercise, will induce a “positive protein balance”, and assuming that appropriate type, quantity and timing of protein ingestion (we’ll come on to some of this) is maintained, we can attain some long term increase in muscle size.

Now, a positive balance does not necessarily equate to increased size in the absence of appropriate resistance training. In fact, muscle protein in response to resistance training is heavily influenced by the training load, exercise type, and structural damage, as well as the amount, type and timing of protein ingestion in the following 24hrs, meaning that the strongest stimulus for muscle growth is the combination of appropriate training and protein intake. This is something we see commonly, particularly in those chasing aesthetics. They sometimes spend more time ensuring that they are chugging back their protein shakes throughout the day, than applying well structured training - and if muscular hypertrophy (growth) is the goal, then the two must go hand in hand.

What you’ll notice with this illustration, is regular, and consistent protein feeding. This is paramount if you’re looking to increase muscle mass, and also important for general function, irrespective of body composition goals. What we commonly see is that people backlog their protein intake to the end of the day. Slice of toast for breakfast, tomato soup and a bread roll for lunch, and heaps of spaghetti bolognese at dinner, may mean that you meet your protein target for the day in terms of an overall number within that 24hr window, but you’ve spent the majority of the day in a negative balance, followed by a larger than necessary intake once dinner time comes. We’ll cover quantity of protein shortly, but the message here is that frequent, adequately sized protein intake should be a priority for muscle health and muscle growth.

the message here is that frequent, adequately sized protein intake should be a priority for muscle health and muscle growth.

So how much is enough, not-enough, and too much? Dietary guidelines state that for sedentary members of the general population should be aiming for between 0.8-1g per kg of bodyweight, per day. So as an example, an 80kg person, should be aiming for between 64-80g of protein daily. For athletes, the general recommendations approximate that 1.6-1.8g per kg of bodyweight are much more adequate. Meaning an 80kg athlete, should be consuming 128-144g of protein per day (which if we spread over 5 meals, 3-4hrs apart, equates to roughly 25-29g per meal - e.g. 1 x Chicken thigh). This highlights that if you were to follow guidelines for “general population” as an athlete, it is incredibly likely that you are going to be falling short of your protein requirement, leading to not only large periods of time in a negative protein balance, but also a whole host of negative health and hormonal consequences. More however, does certainly not mean better, and although you can’t go far without seeing heavily marketed supermarket products and drinks containing 50-60g of protein, single intakes of such values are rarely warranted for the majority of people and athletes.

More however, does certainly not mean better

So for team, combat and intermittent athletes, 1.6-1.8g per kilo - and for endurance athletes, slightly less around the 1.2-1.4g per kg mark. This may seem low, and if you thought that, you’re not alone. There are numerous studies in which athletes have self-reported significantly higher amounts of habitual protein intake, sometimes in excess even of 3g per kg of bodyweight. Although there are times where heightened intake is important, there is an upper limit to how much protein can be effectively absorbed by the body, and protein intake in excess of that are likely stripped of their nitrogen, and excreted (they still however hold their caloric value remember).

Many athletes in fact, significantly over-eat protein, and although this has knock on effects again from a health and hormonal perspective, it also often comes at the expense of carbohydrate intake to still reach a caloric target. Although there are certain populations that may benefit from a slightly higher intake, and occasional mitigating circumstances, anything too far in excess of 2g per kg, and below 1.2g per kg in athletic populations (sport depending) is likely to be having a detrimental impact one way or another. Be sure to tie in your total daily intake, to the recommendations on timing aforementioned to make sure you’re on track. You might be surprised that the majority of foods contain at least some protein, and some personal short-term food tracking might shine a light on your current habits.

Mitigating circumstances. So when might more be needed? Evidence indicates that the amount of muscle mass plays a part in the optimal intake for muscle protein synthesis. As an example, an athlete with lesser muscle mass, may see a plateau in protein synthesis rates beyond a 20g feed (showing no added benefit of a 30g, or 40g feed). Whereas those carrying significantly larger muscle mass may benefit modestly from higher intake of protein in a single feed., irrespective of total body mass.

Besides this, another time when heightened protein intake may be warranted is during times of injury, and particularly, if said injury has led to immobilization (in a cast, or on crutches for an extended periods of time). During such time, the tissue can become what we call “anabolically resistant”, and heightened intakes may be required in order to have the same effect from a protein balance perspective.

There are a host of nutritional strategies available to try and offset muscular atrophy, and minimise the loss of lean tissue during immobilization and injury. These are generally handled on a case to case basis and there are other factors at play, (whether the muscle can still contract/be stimulated) but alongside nutritional and supplement strategies, appropriate support can aid in lean tissue loss.

To finish, rather than going on much longer, I have decided to do some quick Q&A. These questions were asked through social media channels following my Instagram Live with FocusFoodsUK and although I have responded individually, I thought some of these may come under the “FAQ” umbrella, and have decided to share them with you as a tail-note on this post:

Quick Fire Q’s

What about before I go to bed? Understandably, people often wonder what they should do prior to sleep, with a large overnight fast having an impact on 24hr protein balance. Research indicates a dose of 0.6g per kg of protein prior to bed time appears to assist and augment overnight protein synthesis, consequently assisting long term muscle adaptation.

Do I need to ingest carbohydrate with my protein? The addition of carbohydrate to the post exercise meal will only really have an impact on increasing the rate of protein synthesis, if the amount of protein ingested is sub-optimal (anything less than ~0.4g per kg)

Does it matter if I have shakes or food? I always advocate a whole foods approach, and getting your nutrition for responsibly sourced fresh food almost always trumps liquid nutrition for the majority of athletes. There are however, occasions when convenience matters - sometimes when you have multiple sessions in a day, liquid nutrition has its benefits in terms of reducing gastric emptying and meaning you can get appropriate nutrition on board, without having it sit heavy for the next session. It also gives you a handle on knowing exactly what’s going in.

What about drinking my BCAA’s? BCAA’s are an incredibly popular sports nutrition supplement, however the evidence is not particularly convincing in terms of their worth. Personally, as a practitioner - I only really use them post weigh-in for combat athletes, if they are in a relatively dehydrated state (after restoring electrolyte balance and starting to restore adequate fluid balance) in order to aid in the restoration of appropriate digestive enzymes, so that ultimately, the athlete is able to start the re-feeding and re-fueling process.

Now hopefully I have covered some useful topics, and in the future, I’ll delve deeper into a number of other subjects and sub-subjects within protein, such as it’s effect on immunity, and getting to terms on protein quality. But for now, hopefully this overview has been useful.

PRPerformance offers Performance Nutrition support to a variety of athletes and members of the general public. These services range from; an assessment of current eating habits (attained via an intuitive interactive app) and subsequent recommendations, to continuous dietary support, meal plans and fueling strategies aiding body composition and/or physical performance outcomes.

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Thanks for reading,

Paul