Immune, exercise, Nutrition | February 17, 2021 | Author: Naturopath
The association of protein and athletic performance has been an item since ancient times when the Greeks and Roman warriors believed they could achieve greater strength and endurance by eating protein-rich flesh of animals which processed such qualities.
Protein is the major structural and functional constituent of the human body. It is composed of amino acids which serve mainly as “building blocks” for protein. Amino acids also work independently in the making of other important molecules such as hormones and neurotransmitters. Amino acids are considered essential" amino acids which must be obtained from the diet (because they cannot be made by the body) and "non-essential' which can be produced in the body or obtained from dietary protein sources. Some non-essential amino acids are not found in protein. The instructions for linking amino acids in a specific sequence is found in DNA coding.
Protein is constantly being catabolised (broken down) and anabolised (synthesized) in the body to provide for the needs of cells and tissues. This function happens simultaneously and is known as protein turn-over.
Protein is most commonly associated with weight training and body builders due to these sports being about greater protein mass (muscle). Muscle minus the water content is mostly protein. Individuals who train for strength and power, e.g., body builders and footballers, have a greater need for protein related to their level of resistance training, than the average person.
Endurance athletes such as cyclist, triathletes and long-distance runners, also have a greater need related to their training level, due mostly to the increased oxidation of amino acids. The requirements for protein for those performing resistant exercise takes into consideration the maintenance and improvement of lean body mass (LBM).
For all athletes any excess dietary protein consumed, once the diet has met body’s requirement to maximised and compensation for physical training, will not provide any further assistance.
The bottom line for protein - more is not necessarily better.
Protein provides many roles in the body other than building muscle. These include to serve as structural components – contractile filaments and complexes, connective tissue, immune system antibodies, blood clotting factors, transporters in circulation, enzymes and important in the balance of water and pH regulation. Protein can also provide an energy resource – though carbohydrate and fats are considered the main source of energy for the body.
Some amino acids are referred to as glucogenic or ketogenic. The amino acid pool is a small amount of free amino acids found in intracellular fluid and plasma which can be used for energy or converted to glucose and/or ketone bodies in the liver during exercise or fasting.
BCAA’s: valine, leucine and isoleucine, are amino acids with protein anabolic properties. They can be used to promote recovery after exercise, help reduce muscle soreness and regulate immune function.
Tendons and cartilage use connective tissue protein structures, such as collagen and elastin, to provides the strength and elastic properties needed to support muscle and joints.
Collagen is an abundant protein found in tendons, cartilage and skin and the interstitial spaces (in-between cells). Collagen is the strength whereas elastin provides elasticity properties to tissue. This is especially important for any blood vessels under pressure. Other areas where protein provides structural integrity include the protein keratin in hair, nails and skin.
Click Here for further reading
Infections affecting the respiratory and gastrointestinal systems interfere with an athlete’s ability to train and compete. A deficiency of protein or amino acids is associated with impaired immune function and more frequent infection. Malnutrition of protein reduces the concentration of amino acids in plasma which are needed for regulating immune responses. For those with malnutrition and infectious disease, evidence has shown supplementing with amino acids can enhance immunity. Arginine, glutamine and cysteine are amino acids which may help with immune function but individual consumption should be on the advice of a nutritional health-care professional.
It is recommended that athletes follow a balanced diet to avoid deficiency of any nutrients so as to provide for healthy immune function. Nutrients which have been shown to reduce infection in athletes include vitamin C, vitamin D and probiotics.
Protein in the form of collagen forms part of the organic matrix of bone. Collagen is also needed in the production of hormones and growth factors which modulate bone syntheses. Protein is thought to have an indirect affect on bone through muscle mass and function and via the increase in circulating IGF-1 (Insulin-like growth factor 1), which has an anabolic effect on bone.
Consuming protein pre and/or post workout has been evidenced to induce the most significant increase in muscle protein synthesis.
Protein can help physical performance and recovery time for both resistant and endurance athletes, but it is long term dietary intake of calories and protein which helps the body to adapt to exercise.
Whether protein is consumed pre- or post-workout is often influenced by training status. This includes such things as whether the training is for a beginner or advanced athlete, if it is recreational or competitive, and how much exercise is being performed on the day.
The question of what is the best time frame for consuming protein (pre or/and post and how early or late) is outweighed by the importance of consuming it over not consuming anything at all.
Shakes can be an easy way to increase protein intake, particularly for before and after training and performance. Dietary sources of protein include: Meat, fish, poultry, eggs, dairy (milk, yoghurt, cheese), nuts and legumes.
The exact amount of protein needed by an athlete is debatable. Research has indicated an athlete in intensive training may require two times as the RDA of protein in their diet to provide a sufficient amount. If insufficient protein is eaten the result may be seen as: slow exercise recovery time, more injuries, muscle wasting, illnesses and an inability to maintain training.
Athletes and those people engaged in intensive physical activity have a higher requirement for protein and also carbohydrates and fats to be able to achieve optimal performance and body maintenance.
Carbohydrates are needed before, during and after high-intensive training and performance to replenish lost muscle and liver glycogen. Carbohydrates should be obtained from whole grains, fruits and vegetables. Refined sugars and those found in sports supplements are useful when fast resynthesis of glycogen is needed, such as on competition days.
Fats are required much the same or slightly higher as that of the average person. Fats are used to maintain energy, intramuscular triacylglycerol stores and general health. Essential fatty acids are used to reduce inflammation, often increased in acute exercise, and improve anti-inflammatory immune factors. Heathy fats can be obtained from fatty fish (sardines, salmon), nuts, olives and avocado. Fish oil tablets are a convenient way of providing beneficial essential fatty acids.
Physically active people, whether it be athletes or those performing jobs which require physical activity such as builders, garden landscapers or cleaners for example, can benefit from consuming adequate amounts of protein in their diet either from dietary sources or supplemental sources.
Effects of Protein Supplementation on Performance and Recovery in Resistance and Endurance Training https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6142015/
Amino acids and immune function https://pubmed.ncbi.nlm.nih.gov/17403271/
Nutrition and Athlete Immune Health: New Perspectives on an Old Paradigm https://pubmed.ncbi.nlm.nih.gov/31691927/
Branched-chain amino acid supplementation does not enhance athletic performance but affects muscle recovery and the immune system https://pubmed.ncbi.nlm.nih.gov/18974721/
Effect of branched-Chain Amino Acid Supplementation on Muscle Soreness following Exercise: A Meta-Analysis https://pubmed.ncbi.nlm.nih.gov/30938579/
Branched-chain amino acids in health and disease: metabolism, alterations in blood plasma, and as supplements https://nutritionandmetabolism.biomedcentral.com/articles/10.1186/s12986-018-0271-1
Nutrition and Athlete Bone Health https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6901417/
IOC consensus statement: dietary supplements and the high-performance athlete https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5867441/
ISSN exercise & sports nutrition review update: research & recommendations https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6090881/
Dietary fats and immune status in athletes: clinical implications https://pubmed.ncbi.nlm.nih.gov/10910295/