your post workout shake

What are our fuel energy sources?

We have three possible fuel sources, carbohydrate, protein and fat. These are known as macronutrients and, contrary to popular belief that carbohydrates and fat are the devil, they are actually vital for optimum health.

Carbohydrate - is stored in the body as glycogen in both the liver and in muscle cells. Carbohydrate is the body's preferred fuel source. The brain, organs, immune system and muscles all rely on carbohydrate to keep them functioning optimally.

Protein - is mainly stored in muscle in its simplest form, which are amino acids. It is found in every cell of the body and is needed to build and repair tissues such as bone, muscle, cartilage, skin and blood. Protein is also needed to make enzymes, hormones and other body chemicals.

Fat - is stored as triglycerides in adipose cells. Fat is the body's all important energy reserve, every gram contains 9 calories, twice as much as both carbohydrate and protein. Fat is needed for insulation, the production of essential hormones, the absorption and storage of fat soluble vitamins (A, D, E and K), and it contains essential fatty acids (omega 3, 6 and 9), which have many health benefits

What fuels do we use while training?

During a workout we will use all three fuels in varying proportions. During a workout we use different fuels depending on our energy status (fed or starved state), the intensity and duration we are training, what stage of our workout we are at, and what, if any, during training supplement we are using.

When we start our training session, whatever type of training it may be, we begin mainly utilising carbohydrate. At around the 20-minute mark we will start using fat as well. When working at a lower intensity, the fuel predominately used will be from fat with some carbohydrate. As the intensity increases the energy system we use will change, so too will the fuel source (energy systems are covered separately in the geek section). Higher intensity exercise requires faster energy to meet demands, fat oxidation for energy is too slow, (lipolysis, again covered in more detail in geek section). However, carbohydrate can be used rapidly for energy. If you are training at a high intensity for a long period, and carbohydrate stores both in the cell and the blood stream are running low, then the body will start to breakdown protein (gluconeogenesis; glucose obtained from non-carbohydrate carbon substances) from muscle for energy (this is the reason body builders do low intensity cardio). Not only are fats slow to breakdown, but the body also likes to hold on to its high calorific fat reserves, preferring to utilise the lower calorie carbohydrate and protein instead. 

At YBP we will give you a training programme that ensures you are working in the correct energy system, performing the correct exercises, with the ideal rep range and rest period for your body type and goal.

What is happening biologically during and after training?

As we train our body is using fuel, from both our stored reserves and from what is in the blood stream at that time. As mentioned already, we use these fuels in differing ratios depending on many variables. It's important to remember that our body's primary goal is to keep us alive, and to do that it needs a good store of energy, so as the fuel from our blood stream and stored reserves starts to deplete during training our body starts to panic a little. Before we started training our body was most likely in an anabolic state, full up and not needing extra energy. The cells are at this point insensitive to insulin, meaning that they are unresponsive to the effects of insulin. Among other things, the job of insulin is to take sugar out of the blood stream and push it into the cell, for either energy or storage. When we are training our cells are frantically burning the fuel, the body starts to make the cells more insulin sensitive, allowing the hormone to transport and pass the glucose from the blood. It is in this post workout window of around 45 minutes that we are most insulin sensitive and the food/supplement that we consume will be used to replenish our fuel stores. 

Why do we need a post workout shake?

There are several reasons why a post workout shake is essential for anyone trying to get results.

It replenishes stores, so that we don’t feel sluggish the next time we train. Insufficient replenishment will cause you to have low energy during your next training session, which in turn causes you to have a sub-optimal session and ultimately sub-optimal results. Lack of energy could also be down to high stress levels, (which create a nutrient deficiency of important nutrients needed to produce energy), sleep deprivation or over training.

As previously mentioned training, especially at higher intensities, will inevitably cause some protein breakdown from muscle. A post workout shake containing both carbohydrate and protein will help to prevent this. Maintaining muscle is essential. Muscle is biologically active and the more we have the faster our metabolism and the easier it is to reduce body fat.

Training will cause a rise in cortisol, the stress hormone. In an ideal world we want to increase the hormones testosterone and HGH (human growth hormone) and reduce cortisol as it reduces testosterone. A post workout shake containing carbohydrate will help in reducing cortisol levels.

The insulin sensitivity not only promotes the increased uptake of glucose into the cell, but also protein. Whilst training we are essentially damaging muscle fibre so they repair bigger and stronger. Protein, or more accurately amino acids, are required for this repair to take place. Any repair in the body requires energy and, again, this is why carbohydrates are so important.   

Missing the post workout window essentially means missing the opportunity to replenish stores and repair muscle and subsequently optimise your training session.   

What should be in my post workout shake?

The two important ingredients in the post workout shake should be protein and carbohydrate. As a rule I always suggest eating real food over supplements any day, but this is the one time that I believe supplements are better than food. The reason I say this is because real food needs to go through the digestive process and be broken down before it can enter the blood stream. Carbohydrate (depending on the type) can take at least an hour, and protein can take in excess of two hours. As the insulin sensitive window is less than an hour, real food is too slow. A protein shake is the best option, as its powdered form allows for quick absorption. Whey protein is the most bioavailable, however if you have a dairy intolerance you may prefer the many vegan options, from plant sources such as brown rice, pea or flax seeds to name a few. The same applies to the carbohydrate, what the body wants is glucose (dextrose), a fast releasing sugar. Complex carbohydrates are slow releasing and other sugars, like fructose for example, take different metabolic path ways, so glucose is the best option. At YBP we recommend buying a high protein low carb mix and buying the dextrose separately. This allows you to tailor make your protein shake for your body type and goal. 



This article has
been written by
Terry Fairclough