Sports And Dietary Supplements: From Creatine To Whey
Medically reviewed by Carmen Fookes, BPharm. Last updated on Aug 6, 2020.
Creatine: Helping To Pump Up The Billion Dollar Supplement Industry
Creatine is an amino acid that is naturally found in the body - mostly in muscles - where it is stored as creatine phosphate (phosphocreatine). During high-intensity, short-duration sports, phosphocreatine is converted into ATP - the major form of energy used by the body. Our liver, kidneys and pancreas synthesize about 50% of the creatine in our body - which is then transported to our muscles via our blood. The other 50% is obtained through diet. Meat and fish are high in creatine.
Creatine can also be made in a laboratory and creatine supplements are still one of the most popular supplements taken today. Americans consume over 4 million kilograms of creatine supplements every year in an effort to improve lean muscle mass and enhance performance, particularly for sports requiring explosive power such as weight lifting, sprinting and high jumping. This amounts to an annual spend of over 14 million dollars in the U.S. alone.
Creatine: Effective...Or Not?
Creatine is one of the most studied supplements. While plenty of trials show it does indeed boost athletic performance, few were conducted outside of a sports laboratory or in people competing in their everyday sport. Research indicates there may be a wide individual variation in response rates - athletes with naturally high body stores of creatine do not seem to get an extra energy-boost from supplemental creatine. In addition, endurance events, such as middle-to-long distance running, do not appear to benefit from extra creatine.
Response appears more likely in people in their early twenties. Although data investigating the safety of creatine is lacking in teenagers, research has shown that this group is more likely to exceed the recommended loading and maintenance doses. The National Collegiate Athletic Association (NCAA) no longer allows colleges and universities to supply creatine to their students with school funds, although it has not gone as far as to ban its use. Similarly, while not banned by the International Olympic Committee, using it for athletic performance is controversial. Current testing methods are not able to distinguish supplemental creatine from natural body occurrence.
Creatine: Generally Safe But Be Wary Of Large Doses
Generally, creatine appears to be safe with few side effects when taken at recommended dosages for periods of approximately six months. Theoretically, high dosages may cause kidney problems or stop the body from making its own creatine but so far trials have failed to support this. However, experts advise people with pre-existing kidney disease, diabetes, or high blood pressure against supplementation with more than three to five grams per day.
Anecdotal reports of muscle or abdominal cramps and water retention have not been replicated in clinical trials. Probably one of the biggest concerns is contaminated creatine or creatine supplements made by less than reputable companies. Buying a reputable brand from a well recognized supplier is probably the best safe-guard against side effects you could get.
Whey: A Long Way From Incy Bitsy Spider
Milk can be easily separated into two major components: whey (the liquid portion), and curds (the rest that is left behind).
Whey contains proteins, vitamins, fats, carbohydrates and minerals. Whey has been of interest to athletes because it contains all the essential amino acids needed for muscle growth and repair. Whey protein exists in three major forms:
- Whey protein concentrate (WPC): contains low amounts of fat and carbohydrates, and the protein percentage depends on how concentrated the product is (ranges from 30-90%)
- Whey protein isolate (WPI): further processing occurs to remove all the fat and lactose. Protein percentage usually around 90%
- Whey protein hydrolysate (WPH): further processed to improve digestibility and reduce allergen potential.
Whey: Which One To Choose?
Choice of whey protein comes down to budget, allergies, and reasons for supplementation.
Whey protein concentrate (WPC) contains significant amounts of lactose, so should be avoided by anyone with lactose intolerance. However, because it is the least processed of all whey forms, it theoretically has health advantages over the isolate and hydrolysate forms because processing can denature peptides in the whey making them less biologically active, although this appears not to affect muscle-building properties. More expensive methods of processing, such as micro-filtration, yield whey isolates with more potential biological activity.
The most easily digestable, but least active, peptides are found in whey protein hydrolysate. Both isolates and hydrolysates are popular post-work out supplements as they contain a higher amount of protein per serving than WPC, less calories (may be a concern for those watching their weight), and are more readily absorbed into the blood stream. However, they are more expensive, and processing may mean health benefits are less. In addition, their increased absorption rate may cause a more profound insulin response which may not be ideal for people trying to control insulin fluctuations.
Whey: Way Too Good To Be True
Whey protein has been extensively studied and some trials report enhanced muscle growth and improved recovery; however, not all studies have found positive effects. Possibly effectiveness depends on the timing of supplementation, the athletes pre-exisiting nutritional state, and the volume, intensity and frequency of training. One study found no difference in recovery or performance between top cyclists at a training camp supplemented with both protein and carbohydrates compared with those supplemented with carbohydrates alone.
Some experts still favor supplementation with whole foods, preferring a glass of milk, which contains both whey and cassein (beneficial at preventing muscle breakdown) to whey protein alone.
Glutamine: Our Most Abundant Amino Acid
Protein makes up 20% of the human body and consists of smaller building blocks, called amino acids. These join together in chains to make different types of protein. There are 20 different amino acids, and glutamine is the most abundant.
Glutamine helps regulate fluid levels, body temperature, and heart rate; and keeps our pH in balance. Glutamine directly influences how much protein is made, and how much is degraded. It helps our immune system to function as well as our gut.
Under normal conditions, our body makes enough glutamine to satisfy our daily needs. However, certain circumstances, such as strenuous exercise, critical illness, stress, burns, and trauma result in an increased requirement for glutamine.
If glutamine requirements exceed what the body can make, extra glutamine must be provided by the diet. Otherwise our immune system, digestive tract and several other vital cellular processes may suffer.
Glutamine: Why Would Athletes Need Extra?
Glutamine naturally occurs in most animal and plant protein sources; meat, seafood, dairy, eggs, beans and nuts are all high in glutamine. Glutamine is also available as a supplement, L-Glutamine.
Glutamine, taken either in the diet or as a supplement, preserves muscle function and improves nitrogen balance. In addition, it crosses the blood-brain barrier and acts as a precursor to neurotransmitters. In theory, this makes it beneficial in athletes who subject their body to high levels of physical and mental stress and whose requirement for glutamine far exceeds that of a non-training person. Glutamine deficiencies can contribute to suboptimal performance and slow recovery times.
Is The Theoretical Need For Extra Glutamine Supported By Research?
The "Glutamine Hypothesis" based on research conducted by Parry-Billings et al, provides a mechanism to explain the increased susceptibility to infection and immune system impairment common among endurance athletes.
However, reevaluation of this work showed that functioning of immune system cells was only severely impaired when glutamine concentrations dropped below 100 μmol/L. Realistically, even the most over-trained athlete would never reach this value since even with severe burns, glutamine concentrations rarely drop below 200 μmol/L.
In addition, most athletes typically already consume foods high in protein as well as protein supplements, all natural sources of glutamine. Generally, well controlled trials have failed to show any benefit of glutamine supplementation in healthy, well-nourished people.
Trials investigating glutamine supplementation for other conditions (such as young people with cancer undergoing chemotherapy) have shown similar results - no significant difference between glutamine supplementation or no supplementation.
Bottom line is, if your diet contains your recommended daily intake of protein from ANY source (plant or animal), supplementation with extra glutamine is of no benefit.
Pumped Up With Branched Chain Amino Acids (BCAA)?
Branched Chain Amino Acids (BCAA) are back in vogue, particularly with competing body builders on calorie-deficit diets who wish to still maintain muscle mass.
Of the 20 amino acids needed by our body, three have a branched chain structure (leucine, isoleucine and valine) and are ESSENTIAL to our survivial - meaning our bodies cannot make them and they have to be obtained from our diet.
Researched has revealed that when amino acids are in abundance, a sensor called mTORC1 increases protein synthesis and growth. Leucine has been found to be the most potent stimulator of mTORC1 in skeletal muscle, and as a result, it, and its metabolites, are well promoted as both a body building supplement and a potential nutrient for muscle wasting conditions.
But Does The Theory Stack Up In Real Life?
One of the most researched and used BCAAs is beta-hydroxy-beta-methylbutyrate (or HMB for short), a metabolite of leucine. A review of 39 studies found that HMB significantly reduced the risk of exercise-related muscle damage in both trained and untrained individuals as well as preventing muscle loss during chronic diseases. However, not all trials have shown beneficial effects, and some trials have only proven an effect during special situations, such as high altitude training or endurance events at high temperatures.
Notably, many trials investigating beneficial effects of BCAAs for muscle wasting conditions associated with aging, cancer, immobilization or bed rest fall short of finding any significant benefits associated with supplementation. It may be in these circumstances that other factors (as yet unidentified) affect amino acid uptake into muscle.
To summarize, BCAAs do appear beneficial at limiting training-induced muscle damage particularly in people on a caloric-deficit diet. Supplements of BCAAs are typically in free-form requiring no digestion, and as a result have a more immediate impact on protein synthesis than BCAAs contained in whey.
Beta Alanine: Can It Really Boost Your Rep Rate?
Beta-alanine is a naturally occurring amino acid that combines with another amino acid L-histidine to form carnosine. Food sources of beta-alanine include meat, fish, and poultry.
During exercise, carnosine acts as a hydrogen ion buffer. Hydrogen ions are released during high-intensity physical activity which causes the pH of the blood to drop (acidification). This can decrease muscle performance, shorten the time to muscle failure, and cause severe fatigue.
Having high concentrations of carnosine in the blood helps counteract this acid build-up. Unfortunately, carnosine supplementation is ineffective at increasing carnosine levels because it is poorly absorbed into the muscle fibers, unlike beta-alanine which is well absorbed and can be used by the body to make more carnosine. Supplementation with beta-alanine can reportedly raise carnosine levels by over 60% in as little as four weeks.
Unfortunately, a review of studies failed to find any benefit for beta-alanine with regards to increasing muscle strength or aerobic endurance, although there was some evidence that it slightly increased the amount of time an athlete can perform high-intensity exercises before getting exhausted.
Although the International Society of Sports Nutrition considers supplements containing between 2 and 4 grams of beta-alanine safe and efficacious when taken for up to 8 weeks, it is not clear whether this is true for higher dosages or consumption for longer than eight weeks.
A tingly feeling on the skin lasting up to 90 minutes has been reported in some people after taking beta-alanine, particularly after high dosages. The supplement may also interact with some medications used to treat heart disease or erectile dysfunction. Always talk to your doctor before taking any supplements, including beta-alanine.
Is Going Green The Best To Keep Lean?
Taking "Green supplements" - pressed dry powders made from green foods such as alfalfa, algae, fruits, green tea, herbs, probiotics, vegetables, and seaweed - may seem a whole lot easier than trying to eat nine servings of vegetables and fruit per day. But green supplements are not FDA approved, and consumer review groups have found that contamination with bacteria or toxins - such as lead or arsenic - is common.
In addition, there is no requirement for companies manufacturing green supplements to formulate their products to contain all the recommended daily vitamins and minerals. Nutrients such as zinc, magnesium and vitamin B12 are likely to be lacking.
Not all supplements are created equal and if you decide to take green supplements, use a reputable company with good quality control testing that lists each ingredient and quantities on the label. Five servings of vegetables and four of fruit is still the healthiest way to get your recommended daily intake of nutrients.
Finished: Sports And Dietary Supplements: From Creatine To Whey
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