The ultimate guide to training nutrition Nutrients and timing Part 1

Training nutrition can be confusing. Learn more about the role of protein quality and quantity, carbohydrates, fats and nutrient timing in this comprehensive guide

This guide will cover the following topics:

• Why there is no one-size-fits-all approach to nutrition that is optimal for everyone
• What happens to your body during resistance training
• How to optimize your body composition by using the right intra-workout nutrition
• Intra-workout protein quality and quantity and what role both play
• How carbohydrates and fats affect the muscle building and fat loss process
• What steps you can take to optimize your peri-workout diet

There is no one-size-fits-all approach to nutrition

With so many different nutrition theories out there, many people find themselves faced with the arduous task of separating fact from fiction. However, nutrition is not the black or white issue that many people seem to turn it into. The problem with making precise dietary recommendations for a wide range of different people is that nutrition is an area that requires personalization and often trial and error to find what is optimal (and practical) for the person in question. A variety of internal (e.g. metabolic rate, endocrine function, immune response, etc.) and external (e.g. caloric intake, activity level, etc.) characteristics contribute to how we tolerate and utilize certain nutrients.

Furthermore, it would be foolish to ignore the goals and forms of physical activity for which the person in question is nourishing their body. Obviously, a young, 100 kilo bodybuilder striving to build mountains of muscle will have different nutritional needs than a 40 year old housewife preparing for a marathon. This may seem intuitive, but it supports the point that different variables need to be considered when optimizing nutrition.

The aforementioned variables are what make nutrition a field of great diversity and ongoing study, as many approaches are plausible. Some people achieve excellent results by limiting their carbohydrate intake, while others do extremely well with a higher carbohydrate intake combined with a low fat intake. Some people can follow an intermittent fasting diet and achieve excellent results, while others eat every 2 to 3 hours and are just as successful. There is more than one way to Rome - we are an adaptable species and our eating habits are no exception.

Before we go any further, another point to consider is that people tend to go to extremes when it comes to training and nutrition. When someone reads a study that concludes that barbell curls are better for stimulating the biceps than dumbbell curls, this is often interpreted as "dumbbell curls are ineffective as a biceps exercise".

However, this "all or nothing" mindset only imposes unnecessary restrictions on you. The goal should be to find out what is optimal, but also - and more importantly - what is practical for an individual. Even if a certain extreme protocol may be optimal, in most cases it is impractical. And at the end of the day, a protocol that doesn't fit your life - regardless of whether it's optimal or not - is only of theoretical interest.

Part I - What happens to your body during training

Before we look at the nutritional side of things, it's wise to have a basic idea of what happens in our bodies on a physiological level during a training session with weights. This can be a little tricky to summarize as there is a wide range of research showing that different training variables (i.e. volume, intensity, frequency, etc.) elicit different physiological responses (2).

As mentioned earlier, a person (such as a powerlifter) training purely for strength gains will likely use a different training input than a person training for a bodybuilding competition and looking to build more muscle mass (we will discuss this in more detail later in this guide, while this section is intended more as a general overview of the body's physiological responses to training with weights).

For this purpose, we will approach this topic in a way that assumes the exerciser performs resistance training with moderate volume (e.g. 2 to 3 sets of 6 to 12 repetitions per exercise) and moderate intensity (i.e. a weight that is demanding but does not induce muscle failure on the last repetition) three to four times a week. This is a type of training program that is designed to build both strength and muscle mass and represents a balanced approach to activating different muscle fibers (3).

So let's take this program and apply it to a trainee and see what happens during the training sessions from a physiological point of view. When this exerciser performs his exercises, he exerts a contractile force with the necessary muscles during each repetition. To develop this contractile force, the muscle cells use energy (in the form of ATP) and eventually reach a point of exhaustion where no more repetitions can be performed (i.e. the point of muscle failure).

Keep in mind that this is a very abbreviated and simplistic summary of what happens during anaerobic exercise such as intense weight training (going into more detail on the specific mechanisms underlying muscle contractions would only complicate this view unnecessarily).

After a muscle has been sufficiently exhausted via anaerobic pathways, the cells will have been damaged and there will have been an accumulation of metabolic waste products in the surrounding tissue. This leads to an inflammatory repair response, also known as muscle soreness, in the period following the training session (3). Resistance training is therefore the stimulus that the exerciser exposes their muscles to, resulting in an environment of physiological responses.

The specific physiological benefits that this individual will benefit from in response to weight training are numerous and include increased cardiorespiratory capacity, positive adaptations of the endocrine system and desirable changes in muscle tissue morphology (4, 5).

Some of these benefits, such as increased blood flow to muscle tissue and increased insulin sensitivity, are acute in nature, while others are more latent and gradually become more pronounced with habitual training (6, 7). Keep in mind that these acute adaptations are what make up the supposed post-workout anabolic window.

The most important point to remember is that intense training with weights acts as a stimulus to muscle tissue. The muscle tissue is damaged by the training, which leads to a medley of physiological responses. This is why the idea that muscle growth occurs during actual weight training, which is prevalent among some exercisers, is absolute nonsense. The repair and growth of muscle tissue takes place during the recovery phase hours and days after the actual workout (always assuming you are providing your body with the right nutrients).

Does nutrient timing (especially during the period around your workout) matter?

For those unfamiliar with this terminology, nutrition during the period around your workout - also known as peri-workout nutrition - refers to the window of time before, during and after your workout. As alluded to previously, this is believed to be a critical period for athletes and exercisers due to the cascade of desirable metabolic and hormonal responses to exercise, such as upregulation of glucose transport molecules in muscle tissue (1).

Intuitively, we would like to take advantage of every opportunity we have during this window of opportunity, which is especially true if this period is truly the optimal window of opportunity for anabolic purposes. Or why choose the lower-yield option when you can (hypothetically) get more for your efforts?

Unsurprisingly, the question of optimal nutrient timing is on everyone's mind when they think about food. My initial answer is always the same - yes, it matters, but the real question is how big a role. If we take a step back and look at the overall hierarchy of proper nutrition, the specific time at which you consume your nutrients is surprisingly low on the list (at least in the scientific literature). It seems that total macronutrient/energy intake is a far more important factor. However, we still need to define more clearly what exactly the question of nutrient timing refers to in order to give a better answer.

Let's split the question into two parts, one relating to improving body composition and the other to athletic performance. Even if studies don't show a significant change in body composition simply based on different nutrient timing regimens, we can't ignore the fact that some people simply perform better in the gym or at sporting events when they eat a certain way (or perform sporting activities in a fasted state).

Before we go any further into this topic, let's keep in mind that we are looking for what is optimal and practical. Science gives us general guidance on what is optimal, while personal experience and adjustments are what make this practical.

Improving body composition

To achieve maximum benefits for our body composition, we should ideally follow a training nutrition protocol that optimizes two things: Fat burning and muscle hypertrophy. Unfortunately, in theory, these two goals are completely opposite and mutually exclusive, meaning you can't achieve both at the same time. This is probably the biggest problem that competitive bodybuilding and physique athletes have faced since they first set foot in the gym.

Without the use of pharmacological doses of performance-enhancing substances, any attempt to simultaneously optimize both muscle hypertrophy and fat burning is futile (as long as you're not trying to overcome the laws of thermodynamics, which of course you're welcome to try). However, this doesn't mean that you can't improve your body composition during a given period of time.

One thing that most people seem to overlook when setting a new fitness or body development goal is the fact that body weight alone is not a sufficient tool to assess progress. There are few scenarios where the only goal is simply to lose weight or gain weight in order to see quantitative changes on the scale. I would rather see exercisers embrace the idea of constantly trying to improve their body composition.

If this is a new concept to you, it's worth noting that improving body composition refers to improving the ratio of muscle to fat tissue, which ultimately amounts to lowering body fat percentage.

For example, if an exerciser gains 5 pounds of muscle while only gaining 2 pounds of fat, they will improve their body composition. The same would be true if they lost 5 pounds of fat while only losing 1 pound of muscle.

So to recap, we either want to try to maximize our muscle hypertrophy (while limiting fat gain) or maximize our fat burning (while limiting muscle loss). I hope these examples have helped to make the concept of body composition a little more tangible.

Optimizing muscle hypertrophy

Before we get into how we can optimize nutrient intake and nutrient timing around training, we need to understand what constitutes a state of muscle anabolism/hypertrophy. Basically, this goes back to something called protein turnover ratio. This is a quantitative measure of the ratio of muscle protein synthesis to muscle protein breakdown.

A net turnover ratio where muscle protein synthesis is greater than muscle protein breakdown indicates muscle hypertrophy (i.e. an anabolic state), while a net turnover ratio where muscle protein breakdown is greater than muscle protein synthesis indicates a catabolic state.

A medley of factors, including training, nutrient intake, disease, immune responses, gene expression, pharmaceuticals, supplements and more, can cause fluctuations in this ratio.

So, to optimize muscle hypertrophy, we should ideally aim for a high rate of muscle protein synthesis and a low rate of muscle protein breakdown, so that the muscle protein turnover ratio moves towards anabolism. This may seem like a simple task, but muscle protein synthesis is strictly regulated by a protein encoded by the FRAP1 gene in humans, known as mammalian Target of Rapamycin (mTOR) (8).

This protein acts as a backbone for mTOR protein complexes such as mTORC1 and mTORC2, which activate protein synthesis when appropriate cellular states are reached, ultimately resulting in cellular growth and proliferation (9). Although the overall regulation of the protein synthesis pathway is highly complex (and far beyond the focus of this article), it is useful to have this rudimentary understanding of how muscle cells actually grow.

The activity of the mTOR protein complexes is controlled by the energy status of the cells, circulating growth factors and hormones (especially insulin) and oxidative stress. Our aim is therefore to amplify these signals in a way that is conducive to upregulating muscle protein synthesis.

Optimization of fat burning

In fact, the mechanisms required to maximize fat burning are directly antagonistic to the mechanisms involved in muscle hypertrophy (and vice versa). Fat burning appears to be strongly influenced by the enzyme adenosine monophosphate-activated protein kinase (AMPk).

As you probably know, ATP is the energy currency of cells and that the breakdown of ATP yields ADP (adenosine diphosphate) and free energy. AMPk is activated when the cell is in a state of energy deficiency (i.e. the ratio of ATP to ADP drops). This occurs during periods of nutrient deprivation (especially glucose), exercise, ischemia, and/or under the influence of certain chemicals/medications. Intuitively, it becomes clear that things like eating and excessive glycogen levels inhibit AMPk activity (as the ATP to ADP ratio increases).

You may now be asking why this is of interest. Well, simply put, because AMPk increases lipolysis, stimulates fatty acid oxidation, improves glucose uptake into muscle tissue and inhibits lipogenesis (18). Basically, AMPk is the "metabolic switch" for fat burning.

One or the other: the AMPk-mTOR swing

Herein lies the dilemma we talked about earlier, whereby we can't maximize muscle hypertrophy and fat oxidation at the same time, as they are driven by antagonistic mechanisms. While AMPk is great for fat burning, it is also an inhibitor of mTOR (and therefore muscle protein synthesis) (19). mTOR "returns the favor" by inhibiting AMPk, which means that fat burning is inhibited when muscle protein synthesis is activated.

If you think about all this pragmatically, it makes sense as cellular energy levels at any given time in terms of ATP to ADP ratio can only be either sufficient or low. While this is admittedly a very simplified overview of these metabolic pathways, it's enough to give us an idea of why you can't build muscle and burn fat at the same time.

This is not to say that it is not possible to switch back and forth between these two states, and in fact this is the basic idea behind certain nutritional strategies such as intermittent fasting and refeed protocols. Theoretically speaking, it would be wise to give each of these pathways (AMPk/mTOR) sufficient stimulation/activation if you are trying to improve your body composition. Hence the swing analogy.

In the next part, I will discuss the individual macronutrients and optimal nutrient intake before, during and after training.

Source: https://www.muscleandstrength.com/expert-guides/workout-nutrition