Sports Nutrition and Protein

‘The Power of the Building Block

Similar to carbohydrates, the protein debate has been rolling on for what seems like a life-time!

With regards to type, source, quantity, and the timing of consumption, athletes, coaches, and academics alike have been, and still are attempting to underline what’s right, and what’s not so right with regards to the consumption of protein.

It is well documented that the majority of athletes consume sufficient amounts of protein in their day-to-day diet, however, current evidence is showing that the type of protein (animal vs plant sources) and the timing of ingestion (pre-vs-post exercise) may affect protein kinetics and training adaptations (1).

But what is protein, and what do amino acids do?…where does protein come from, and how does our body use it?…

Protein is an essential nutrient, and like its carbohydrate counterpart has an energy density of 4kcals per gram. Unlike carbohydrates and lipids (fat), protein make-up contains nitrogen atoms, and it is these atoms which give proteins their name of amino (nitrogen containing) acids. Structurally, proteins consist of a varied number of amino acid combinations which are interconnected by peptide bonds, and can contain in excess of 100 separate amino acids.

Amino acids are the building blocks of muscle tissue and are obtained via intercellular synthesis, and from the foods which we eat. The proteins which are manufactured by our bodies are categorized as non-essential [12], and those which are vital to obtain from the foods we eat are categorized as essential [9] proteins (see Table 1).

The liver, muscles, and blood, make up the amino acid pools of the body, and are consistently turning over, and interacting with one another.

When the nitrogen atoms of protein enter in to the amino acid pools a state of nitrogen balance needs to be achieved. During fasting, and over-training, nitrogen status will be in a state of negativity, whereas when protein intake equates to the rate of excretion, then a state of balance is found, and recovery and the rebuilding of muscle tissue is optimized (1).

The terms of essential & non-essential protein are a little misleading, as both categories of protein are essential with regards to the human body being able to function correctly, and optimally, just one can be manufactured in the body, and one cannot, so needs to be ingested via the foods which we eat. The best, and easiest way to make sure that your body can manufacture all the needed proteins is to consume a wide variety of amino acid containing foods, such as meats, fish, dairy, legumes, vegetables, and nuts & seeds (see Table 2).

Protein Digestion & Absorption:

The proteins which we consume begin to be digested in the stomach (2) where they are broken down in to smaller protein molecules called polypeptides. These smaller molecules are then broken down again, in to individual amino acids, which then go to the amino acid pools in the body where they can be called in to action to synthesize protein-based tissues, or as an energy substrate if carbohydrate levels have been totally diminished.

Typically, previous research has concluded that humans can only absorb ~95% of ingested animal proteins, and ~85% of ingested plant protein sources, and therefore individuals who live a vegetarian and/or plant-based lifestyle may need to consume more protein, and a wider variety of plant protein sources than those who consume regular meals containing animal proteins.

 

Protein Requirements:

Protein recommendations in the current literature range from 1.2-2g/kg.bw/per day (3), depending on the individuals’ training regime and body composition goals. During increased volume and intensity phases of training, the higher range values should be aimed for to help minimize greater muscle damage. This is recommended to be achieved through a food-first approach, and with sports supplements being used as just that…supplementing a varied, well-balanced diet. However, some people may find it difficult to stomach real food after training, or may have an extended journey home afterwards, so there is no reason a protein shake, or recovery drink such as Mountain Fuel® Ultimate Recovery Fuel cannot be used in similar situations as this to supplement the protein requirements of your body until a high-protein meal can be consumed.

There is no real definitive amount of protein which one can absorb during a single meal, however it is recommended that total daily intake of protein is spread out throughout the day due to potential utilization issues when consuming large amounts of protein in one sitting.

 

Protein Functions:

As athletes, I am sure that we all know that to become stronger, and too recovery faster we need to eat foods which contain protein, and yes, this is absolutely true…however, protein has many more functions than just supporting growth, repairing & maintaining muscles in our bodies. Proteins, and their individual amino acids are literally super-charged building blocks and sustain also other bodily tissues such as tendons, ligaments, skin, hair and our nails.

Proteins are also used to form hormones, enzymes, and neurotransmitters, all of which carry out vital functions such as the usage and storage of macronutrients. Antibodies, to aid the immune system are created through protein consumption. As are the oxygen transporting proteins of haemoglobin. Proteins are a fuel source, though a small percentage of energy comes from protein, it still does provide some, especially when other exercise substrates are low. Protein is also crucial to controlling fluid volume and water balance in the body (2).

So, you see, the power of the building block is not just about building muscle and becoming stronger, it is key to many different bodily functions which help to optimize health, and performance.

The periodization of protein, like carbohydrates is a key factor in to optimizing good health, and optimizing training performance and recovery, and consequently for such an in-depth topic shall be discussed in a future article!…

 

Key Points:

  • Protein is an essential nutrient, and like its carbohydrate counterpart has an energy density of 4kcals per gram
  • Amino acids are the building blocks of muscle tissue and are obtained via intercellular synthesis, and from the foods which we eat
  • There are 12 non-essential amino acids which are manufactured in the body, and 9 essential amino acids which are vital to obtain from the foods we eat
  • An intracellular nitrogen balance must be attempted, and this is when protein intake equates to the rate of excretion during training
  • The best, and easiest way to make sure that your body can manufacture all the needed proteins is to consume a wide variety of amino acid containing foods, such as meats, fish, dairy, legumes, vegetables, and nuts & seeds
  • Protein recommendations in the current literature range from 1.2-2g/kg.bw/per day, depending on the individuals’ training regime and body composition goals
  • Proteins, and their individual amino acids are literally super-charged building blocks which aid in repair, manufacturing, and maintaining various bodily functions

Next time: Sports Nutrition and Fat ‘Friend, or Foe?’

 

 

Table 1: Function & Source of Essential Amino Acids

Amino Acid Function Food Source

(not limited)

Histidine Growth and development Bananas, beans, dairy, eggs, fish, garlic, meats, mushrooms, turnip
Isoleucine Muscle production, maintenance & recovery, haemoglobin formation, blood-sugar regulation and blood-clot formation Almonds, avocado, coconut, eggs, lentils, meats, olives, most seeds, soy protein
Leucine Growth hormone production, tissue production & repair. Prevents muscle wasting Asparagus, beef, cheese, chickpeas, fish, nuts, oats, rice, walnuts
Lysine Calcium absorption, bone development, nitrogen maintenance, tissue repair, hormone production, and antibody production Amaranth, apricots, beets, carrots, fish, grapes, parsley, pears, sirloin steak
Methionine Fat emulsifier, digestion, antioxidant, hormone production, arterial plaque prevention, and heavy metal removal Brazil nuts, eggs, fish, meats, oats, seeds, spinach, water-cress
Phenylalanine Pre-curser for tyrosine, dopamine, norepinephrine, and epinephrine, as well as the skin pigment: melanin. Supports learning and memory, brain processes, and mood elevation. Cashew nuts, cheese, flax seeds, nutritional yeast, pineapples, seeds, tomatoes
Threonine Monitors bodily proteins for maintaining or recycling processes Celery, dairy, eggs, fish, kale, nori, nuts, papayas, seeds, walnuts
Tryptophan Needed for niacin production, serotonin production, pain management, and sleep & mood regulation Brussel sprouts, chives, cottage cheese, eggs, fennel, nutritional yeast, poultry, red meats, spinach, seeds,
Valine Helps muscle production, recovery, energy, endurance by balancing out nitrogen levels and is used in the treatment of alcohol-related brain damage Apples, beets, dairy, meats, parsnips, pomegranates, potatoes, soy protein, squash, tomatoes

 

Table 2: Food Sources of Protein

Food Items Portion Serving Protein Content
Animal Sources

Chicken

Pork

Beef

White Fish

Eggs

Scallops

Tinned Tuna

Cooked Ham

 

100g

100g

100g

100g

3

118g

80g

125g

 

25g

23g

21g

20g

20

20g

20g

20g

Legumes & Soya

Tofu

Nuts & Seeds

Lentils

Kidney Beans

Tempeh

Soy Milk

Peanut Butter

 

120g

100g

225g

250g

120ml

240ml

2tbsp

 

20g

20g

20g

20g

16g

10g

8g

Dairy

Milk

Yoghurt

Cheese

 

240ml

180ml

30g

 

8g

8g

7g

Vegetable

Potatoes

Mushroom (Oyster)

Broccoli

Carrots

 

150g

1 cup

100g

100g

 

5g

5g

2.5g

1g

Supplements

Mountain Fuel® Ultimate Recovery Fuel drink

 

50g

 

11.2g

(including all 9-essential amino acids)

     

 

References:

1– Zeigenfuss, T.N and Landis, J. (2013). Essentials of Sports Nutrition and Supplements: Carbohydrates. NJ, USA, Humana Press

2– Ryan. M. (2012) Sports Nutrition for Endurance Athletes (3rd Ed.). Colorado, USA, Velo Press

3– Thomas, D.T., Erdman, K. A. and Burke, L.M. Position of the Academy of Nutrition & Dietetics, Dietitians of Canada and the American College of Sports Medicine: Nutrition and Athletic Performance. Journal Academy of Nutrition & Dietetics. 116 (3) 501-528 (2016)