Sports nutrition strategies -
In any event, the likelihood of another revised Draft Guidance from FDA becoming available in the future is high, and possibly more enforcement actions taken against companies that market an NDI without submitting a notification. In response to growing criticism of the dietary supplement industry, the th Congress passed the first mandatory Adverse Event Reporting AER legislation for the dietary supplement industry.
In December , President Bush signed into law the Dietary Supplement and Nonprescription Drug Consumer Protection Act, which took effect on December 22, After much debate in Congress and input from the FDA, the American Medical Association AMA , many of the major supplement trade associations, and a host of others all agreed that the legislation was necessary and the final version was approved by all.
The law strengthens the regulatory structure for dietary supplements and builds greater consumer confidence, as consumers have a right to expect that if they report a serious adverse event to a dietary supplement marketer the FDA will be advised about it.
An adverse event is any health-related event associated with the use of a dietary supplement that is adverse. A serious adverse event is an adverse event that A results in i death, ii a life-threatening experience, iii inpatient hospitalization, iv a persistent or significant disability or incapacity, or v a congenital anomaly or birth defect; or B requires, based on reasonable medical judgment, a medical or surgical intervention to prevent an outcome described under subparagraph A.
Once it is determined that a serious adverse event has occurred, the manufacturer, packer, or distributor responsible person of a dietary supplement whose name appears on the label of the supplement shall submit to the Secretary of Health and Human Services any report received of the serious adverse event accompanied by a copy of the label on or within the retail packaging of the dietary supplement.
The responsible person has 15 business days to submit the report to FDA after being notified of the serious adverse event. Following the initial report, the responsible person must submit follow-up reports of new medical information that they receive for one-year.
The FDA has various options to protect consumers from unsafe supplements. The FDA also has the authority to protect consumers from dietary supplements that do not present an imminent hazard to the public but do present certain risks of illness or injury to consumers. The law prohibits introducing adulterated products into interstate commerce.
The standard does not require proof that consumers have actually been harmed or even that a product will harm anyone.
It was under this provision that the FDA concluded that dietary supplements containing ephedra, androstenedione, and DMAA presented an unreasonable risk. Most recently, FDA imposed an importation ban on the botanical Mitragyna speciose, better known as Kratom.
In , FDA issued Import Alert 54—15, which allows for detention without physical examination of dietary supplements and bulk dietary ingredients that are, or contain, Kratom. Criminal penalties are present for a conviction of introducing adulterated supplement products into interstate commerce.
While the harms associated with dietary supplements may pale in comparison to those linked to prescription drugs, recent pronouncements from the U. Department of Justice confirm that the supplement industry is being watched vigilantly to protect the health and safety of the American public.
When DSHEA was passed in , it contained a provision requiring that the FDA establish and enforce current Good Manufacturing Practices cGMPs for dietary supplements.
However, it was not until that the cGMPs were finally approved, and not until that the cGMPs applied across the industry, to large and small companies alike. The adherence to cGMPs has helped protect against contamination issues and should serve to improve consumer confidence in dietary supplements.
The market improved as companies became compliant with cGMPs, as these regulations imposed more stringent requirements such as Vendor Certification, Document Control Procedures, and Identity Testing.
These compliance criteria addressed the problems that had damaged the reputation of the industry with a focus on quality control, record keeping, and documentation.
However, it does appear that some within the industry continue to struggle with compliance. In Fiscal Year , it was reported that approximately Further, Undoubtedly, relying on certificates of analysis from the raw materials supplier without further testing, or failing to conduct identity testing of a finished product, can result in the creation of a product that contains something it should not contain such as synthetic chemicals or even pharmaceutical drugs.
All members of the industry need to ensure compliance with cGMPs. According to the Nutrition Labeling and Education Act NLEA , the FDA can review and approve health claims claims describing the relationship between a food substance and a reduced risk of a disease or health-related condition for dietary ingredients and foods.
However, since the law was passed it has only approved a few claims. The delay in reviewing health claims of dietary supplement ingredients resulted in a lawsuit, Pearson v.
Shalala , filed in After years of litigation, in the U. Court of Appeals for the District of Columbia Circuit ruled that qualified health claims may be made about dietary supplements with approval by FDA, as long as the statements are truthful and based on adequate science.
Supplement or food companies wishing to make health claims or qualified health claims about supplements can submit research evidence to the FDA for review. The FTC also regulates the supplement industry. Further, before marketing products, they must have evidence that their supplements are generally safe to meet all the requirements of DSHEA and FDA regulations.
This has increased job opportunities for sports nutrition specialists as well as enhanced external funding opportunities for research groups interested in exercise and nutrition research.
While the push for more research is due in part to greater scrutiny from the FDA and FTC, it is also in response to an increasingly competitive marketplace where established safety and efficacy attracts more consumer loyalty and helps ensure a longer lifespan for the product in commerce.
Companies that adhere to these ethical standards tend to prosper while those that do not will typically struggle to comply with FDA and FTC guidelines resulting in a loss of consumer confidence and an early demise for the product.
A common question posed by athletes, parents, and professionals surrounding dietary supplements relates to how they are manufactured and perceived supplement quality.
In several cases, established companies who develop dietary supplements have research teams who scour the medical and scientific literature looking for potentially effective nutrients. These research teams often attend scientific meetings and review the latest patents, research abstracts presented at scientific meetings, and research publications.
Leading companies invest in basic research on nutrients before developing their supplement formulations and often consult with leading researchers to discuss ideas about dietary supplements and their potential for commercialization.
Other companies wait until research has been presented in patents, research abstracts, or publications before developing nutritional formulations featuring the nutrient.
Upon identification of new nutrients or potential formulations, the next step is to contact raw ingredient suppliers to see if the nutrient is available, if it is affordable, how much of it can be sourced and what is the available purity.
Sometimes, companies develop and pursue patents involving new processing and purification processes because the nutrient has not yet been extracted in a pure form or is not available in large quantities. Reputable raw material manufacturers conduct extensive tests to examine purity of their raw ingredients.
When working on a new ingredient, companies often conduct series of toxicity studies on the new nutrient once a purified source has been identified. The company would then compile a safety dossier and communicate it to the FDA as a New Dietary Ingredient submission, with the hopes of it being allowed for lawful sale.
When a powdered formulation is designed, the list of ingredients and raw materials are typically sent to a flavoring house and packaging company to identify the best way to flavor and package the supplement.
In the nutrition industry, several main flavoring houses and packaging companies exist who make many dietary supplements for supplement companies. Most reputable dietary supplement manufacturers submit their production facilities to inspection from the FDA and adhere to GMP, which represent industry standards for good manufacturing of dietary supplements.
Some companies also submit their products for independent testing by third-party companies to certify that their products meet label claims and that the product is free of various banned ingredients.
For example, the certification service offered by NSF International includes product testing, GMP inspections, ongoing monitoring and use of the NSF Mark indicating products comply with inspection standards, and screening for contaminants. More recently, companies have subjected their products for testing by third party companies to inspect for banned or unwanted substances.
These types of tests help ensure that the dietary supplement made available to athletes do not contained substances banned by the International Olympic Committee or other athletic governing bodies e. While third-party testing does not guarantee that a supplement is void of banned substances, the likelihood is reduced e.
Moreover, consumers can request copies of results of these tests and each product that has gone through testing and earned certification can be researched online to help athletes, coaches and support staff understand which products should be considered.
In many situations, companies who are not willing to provide copies of test results or certificates of analysis should be viewed with caution, particularly for individuals whose eligibility to participate might be compromised if a tainted product is consumed.
The ISSN recommends that potential consumers undertake a systematic process of evaluating the validity and scientific merit of claims made when assessing the ergogenic value of a dietary supplement [ 1 , 4 ].
This can be accomplished by examining the theoretical rationale behind the supplement and determining whether there is any well-controlled data showing the supplement is effective. Supplements based on sound scientific rationale with direct, supportive research showing effectiveness may be worth trying or recommending.
Sports nutrition specialists should be a resource to help their clients interpret the scientific and medical research that may impact their welfare and help them train more effectively. The following are recommended questions to ask when evaluating the potential ergogenic value of a supplement.
Most supplements that have been marketed to improve health or exercise performance are based on theoretical applications derived from basic science or clinical research studies. Based on these preliminary studies, a dietary approach or supplement is often marketed to people proclaiming the benefits observed in these basic research studies.
Although the theory may appear relevant, critical analysis of this process often reveals flaws in the scientific logic or that the claims made do not quite match up with the cited literature. By evaluating the literature one can discern whether or not a dietary approach or supplement has been based on sound scientific evidence.
To do so, one is recommended to first read reviews about the training method, nutrient, or supplement from researchers who have been intimately involved in the available research and consult reliable references about nutritional and herbal supplements [ 1 , 9 ].
To aid in this endeavour, the ISSN has published position statement on topics related to creatine [ 10 ], protein [ 11 ], beta-alanine [ 12 ], nutrient timing [ 13 ], caffeine [ 14 ], HMB [ 15 ], meal frequency [ 16 ], energy drinks [ 17 ], and diets and body composition [ 18 ].
Each of these documents would be excellent resources for any of these topics. In addition, other review articles and consensus statements have been published by other researchers and research groups that evaluate dietary supplements, offer recommendations on interpreting the literature, and discuss the available findings for several ingredients that are discussed in this document [ 19 , 20 , 21 ].
A quick look at these references will often help determine if the theoretical impetus for supplementing with an ingredient is plausible or not. Proponents of ergogenic aids often overstate claims made about training devices and dietary supplements while opponents of ergogenic aids and dietary supplements are often either unaware or are ignorant of research supporting their use.
Sports nutrition specialists have the responsibility to know the literature and search available databases to evaluate the level of merit surrounding a proposed ergogenic aid. Some athletic associations have banned the use of various nutritional supplements e.
and many professional sports organization have now written language into their collective bargaining agreements that products made available by the team must be NSF certified as safe for sport. Obviously, if the supplement is banned, the sports nutrition specialist should discourage its use.
In addition, many supplements lack appropriate long-term safety data. People who consider taking nutritional supplements should be well aware of the potential side effects so they can make an informed decision whether to use a supplement.
Additionally, they should consult with a knowledgeable physician to see if any underlying medical problems exist that may contraindicate its use.
When evaluating the safety of a supplement, it is suggested to determine if any side effects have been reported in the scientific or medical literature.
In particular, we suggest determining how long a particular supplement has been studied, the dosages evaluated, and whether any side effects were observed.
Unfortunately, many available supplements have not had basic safety studies completed that replicate the length of time and dosages being used. The next question to ask is whether any well-controlled data are available showing effectiveness of the proposed ergogenic aid in athletic populations or people regularly involved in exercise training.
The first place to look is the list of references cited in marketing material supporting their claims. Are the abstracts or articles cited just general references or specific studies that have evaluated the efficacy of the nutrients included in the formulation or of the actual supplement?
From there, one can critically evaluate the cited abstracts and articles by asking a series of questions:. For perspective, studies reporting improved performance in rats or an individual diagnosed with type 2 diabetes may be insightful, but research conducted on non-diabetic athletes is much more practical and relevant.
Were the studies well controlled? For ergogenic aid research, the gold standard study design is a randomized, double-blind, placebo controlled clinical trial.
This means that neither the researcher nor the subject is aware which group received the supplement or the placebo during the study and that the subjects were randomly assigned into the placebo or supplement group.
At times, supplement claims have been based on poorly designed studies i. or testimonials which make interpretation more difficult. Well-controlled clinical trials provide stronger evidence as to the potential ergogenic value and importantly how the findings can best be used.
Do the studies report statistically significant results or are claims being made on non-significant means or trends? Appropriate statistical analysis of research results allows for an unbiased interpretation of data.
Although studies reporting statistical trends may be of interest and lead researchers to conduct additional research, studies reporting statistically significant results are obviously more convincing. With this said, it is important for people to understand that oftentimes the potential effect a dietary supplement or diet regimen may have above and beyond the effect seen from the exercise bout or an accepted dietary approach is quite small.
In addition, many studies examining a biochemical or molecular biology mechanism can require invasive sampling techniques or the study population being recruited is unique very highly trained resulting in a small number of study participants.
When viewed together, the combination of these two considerations can result in statistical outcomes that do not reach statistical significance even though large mean changes were observed. In all such cases, additional research is warranted to further examine the potential ergogenic aid before conclusions can be made.
Do the results of the cited studies match the claims made about the supplement or do they accurately portray the response of the supplement against an appropriate placebo or control group?
It is not unusual for marketing claims to greatly exaggerate the results found in the actual studies and do so by focusing upon just the outcomes within the supplement treatment group as opposed to how the supplement group changed in comparison to how a placebo group changed.
Similarly, it is not uncommon for ostensibly compelling results, that may indeed be statistically significant, to be amplified while other relevant findings of significant consumer interest are obscured or omitted e.
a dietary supplement showing statistically significant increases in circulating testosterone yet changes in body composition or muscular performance were not superior to a placebo.
Reputable companies accurately and completely report results of studies so that consumers can make informed decisions about using a product. At times, claims are based on research that has either never been published or only published in an obscure journal. If you see only a few other journals this is a suggestion that the journal is not a reputable journal.
Additionally, one can also look up how many articles have been published by the journal in the last 6—12 months and how many of these articles are well-conducted studies.
Impact factors are determined and published by Thomson Reuters under Journal Citation Reports® a subscription service available at most university libraries. Most journals list their impact factor on the journal home page.
Historically, those articles that are read and cited the most are the most impactful scientifically. Have the research findings been replicated? If so, have the results only been replicated at the same laboratory?
The best way to know an ergogenic aid works is to see that results have been replicated in several studies preferably by several separate, distinct research groups. The most reliable ergogenic aids are those in which multiple studies, conducted at different labs, have reported similar results of safety and efficacy.
Additionally, replication of results by different, unaffiliated labs with completely different authors also removes or reduces the potentially confounding element of publication bias publication of studies showing only positive results and conflicts of interest. A notable number of studies on ergogenic aids are conducted in collaboration with one or more research scientists or co-authors that have a real or perceived economic interest in the outcome of the study.
This could range from being a co-inventor on a patent application that is the subject of the ergogenic aid, being paid or receiving royalties from the creation of a dietary supplement formulation, providing consulting services for the company or having stock options or shares in a company that owns or markets the ergogenic aid described in the study.
An increasing number of journals require disclosures by all authors of scientific articles, and including such disclosures in published articles. This is driven by the aim of providing greater transparency and research integrity. It is important to emphasize that disclosure of a conflict of interest does not alone discredit or dilute the merits of a research study.
The primary thrust behind public disclosures of potential conflicts of interest is first and foremost transparency to the reader and second to prevent a later revelation of some form of confounding interest that has the potential of discrediting the study in question, the findings of the study, the authors, and even the research center or institution where the study was conducted.
Dietary supplements may contain carbohydrate, protein, fat, minerals, vitamins, herbs, enzymes, metabolic intermediates i. Supplements can generally be classified as convenience supplements e. As discussed previously, evaluating the available scientific literature is an important step in determining the efficacy of any diet, diet program or dietary supplement.
In considering this, nutritional supplements can be categorized in the following manner:. Strong Evidence to Support Efficacy and Apparently Safe: Supplements that have a sound theoretical rationale with the majority of available research in relevant populations using appropriate dosing regimens demonstrating both its efficacy and safety.
Limited or Mixed Evidence to Support Efficacy: Supplements within this category are characterized as having a sound scientific rationale for its use, but the available research has failed to produce consistent outcomes supporting its efficacy.
Routinely, these supplements require more research to be completed before researchers can begin to understand their impact. Importantly, these supplements have no available evidence to suggest they lack safety or should be viewed as harmful.
Several factors are evaluated when beginning to counsel individuals who regularly complete exercise training. To accomplish this, one should make sure the athlete is eating an energy balanced, nutrient dense diet that meets their estimated daily energy needs and that they are training intelligently.
Far too many athletes or coaches focus too heavily upon supplementation or applications of supplementation and neglect these key fundamental aspects. Following this, we suggest that they generally only recommend supplements in category I i. If an athlete is interested in trying supplements in category II i.
Obviously, the ISSN does not support athletes taking supplements in category III i. We believe this approach is scientifically substantiated and offers a balanced view as opposed to simply dismissing the use of all dietary supplements.
A well-designed diet that meets energy intake needs and incorporates proper timing of nutrients is the foundation upon which a good training program can be developed [ 22 , 23 ].
Incorporating good dietary practices as part of a training program is one way to help optimize training adaptations and prevent overtraining. The following is an overview of energy intake recommendations and major nutrient needs for active individuals.
The primary component to optimize training and performance through nutrition is to ensure the athlete is consuming enough calories to offset energy expenditure [ 22 , 23 , 24 , 25 , 26 ]. People who participate in a general fitness program e. However, athletes involved in moderate levels of intense training e.
For elite athletes, energy expenditure during heavy training or competition will further exceed these levels [ 27 , 28 ]. Additionally, caloric needs for large athletes i. This point was clearly highlighted in a review by Burke who demonstrated that carbohydrate needs are largely unmet by high-level athletes [ 22 ].
Additionally it is difficult to consume enough food and maintain gastrointestinal comfort to train or race at peak levels [ 35 ]. Maintaining an energy deficient diet during training often leads to a number of physical i.
and psychological i. It is still a question whether there may be specific individualized occasions when negative energy balance may enhance performance in the days prior to running performance [ 36 ]. Populations susceptible to negative energy balance include runners, cyclists, swimmers, triathletes, gymnasts, skaters, dancers, wrestlers, boxers, and athletes attempting to lose weight too quickly [ 37 ].
Additionally, female athletes are at particular risk of under fueling due to both competitive and aesthetic demands of their sport and their surrounding culture. Female athletes have been reported to have a high incidence of eating disorders [ 38 ].
This makes LEA a major nutritional concern for female athletes [ 39 ]. Consequently, it is important for the sports nutrition specialist working with athletes to assess athletes individually to ensure that athletes are well fed according to the goals of their sport and their health, and consume enough calories to offset the increased energy demands of training, and maintain body weight.
Further, travel and training schedules may limit food availability or the types of food athletes are accustomed to eating. This means that care should be taken to plan meal times in concert with training, as well as to make sure athletes have sufficient availability of nutrient dense foods throughout the day for snacking between meals e.
Beyond optimal energy intake, consuming adequate amounts of carbohydrate, protein, and fat is important for athletes to optimize their training and performance.
In particular and as it relates to exercise performance, the need for optimal carbohydrates before, during and after intense and high-volume bouts of training and competition is evident [ 41 ].
Excellent reviews [ 42 , 43 ] and original investigations [ 44 , 45 , 46 , 47 , 48 , 49 ] continue to highlight the known dependence on carbohydrates that exists for athletes competing to win various endurance and team sport activities.
A complete discussion of the needs of carbohydrates and strategies to deliver optimal carbohydrate and replenish lost muscle and liver glycogen extend beyond the scope of this paper, but the reader is referred to several informative reviews on the topic [ 23 , 41 , 50 , 51 , 52 , 53 ].
As such, individuals engaged in a general fitness program and are not necessarily training to meet any type of performance goal can typically meet daily carbohydrate needs by consuming a normal diet i. However, athletes involved in moderate and high-volume training need greater amounts of carbohydrate and protein discussed later in their diet to meet macronutrient needs [ 50 ].
In terms of carbohydrate needs, athletes involved in moderate amounts of intense training e. Research has also shown that athletes involved in high volume intense training e. Preferably, the majority of dietary carbohydrate should come from whole grains, vegetables, fruits, etc.
while foods that empty quickly from the stomach such as refined sugars, starches and engineered sports nutrition products should be reserved for situations in which glycogen resynthesis needs to occur at accelerated rates [ 53 ].
When considering the carbohydrate needs throughout an exercise session, several key factors should be considered. Previous research has indicated athletes undergoing prolonged bouts 2—3 h of exercise training can oxidize carbohydrates at a rate of 1—1.
Several reviews advocate the ingestion of 0. It is now well established that different types of carbohydrates can be oxidized at different rates in skeletal muscle due to the involvement of different transporter proteins that result in carbohydrate uptake [ 55 , 56 , 57 , 58 , 59 ].
Interestingly, combinations of glucose and sucrose or maltodextrin and fructose have been reported to promote greater exogenous rates of carbohydrate oxidation when compared to situations when single sources of carbohydrate are ingested [ 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 ].
These studies generally indicate a ratio of 1—1. In addition to oxidation rates and carbohydrate types, the fasting status and duration of the exercise bout also function as key variables for athletes and coaches to consider. When considering duration, associated reviews have documented that bouts of moderate to intense exercise need to reach exercise durations that extend well into 90th minute of exercise before carbohydrate is shown to consistently yield an ergogenic outcome [ 41 , 68 , 69 ].
Of interest, however, not all studies indicate that shorter 60—75 min bouts of higher intensity work may benefit from carbohydrate delivery. Currently the mechanisms surrounding these findings are, respectively, thought to be replacement of depleted carbohydrate stores during longer duration of moderate intensity while benefits seen during shorter, more intense exercise bouts are thought to operate in a central fashion.
Moreover, these reviews have also pointed to the impact of fasting status on documentation of ergogenic outcomes [ 41 , 68 , 69 ]. In this respect, when studies require study participants to commence exercise in a fasted state, ergogenic outcomes are more consistently reported, yet other authors have questioned the ecological validity of this approach for competing athletes [ 43 ].
As it stands, the need for optimal carbohydrates in the diet for those athletes seeking maximal physical performance is unquestioned. Daily consumption of appropriate amounts of carbohydrate is the first and most important step for any competing athlete.
As durations extend into 2 h, the need to deliver carbohydrate goes up, particularly when commencing exercise in a state of fasting or incomplete recovery. Once exercise ceases, several dietary strategies can be considered to maximally replace lost muscle and liver glycogen, particularly if a limited window of recovery exists.
In these situations, the first priority should lie with achieving aggressive intakes of carbohydrate while strategies such as ingesting protein with lower carbohydrate amounts, carbohydrate and caffeine co-ingestion or certain forms of carbohydrate may also help to facilitate rapid assimilation of lost glycogen.
Initially, it was recommended that athletes do not need to ingest more than the RDA for protein i. However, research spanning the past 30 years has indicated that athletes engaged in intense training may benefit from ingesting about two times the RDA of protein in their diet 1.
If an insufficient amount of protein is consumed, an athlete will develop and maintain a negative nitrogen balance, indicating protein catabolism and slow recovery. Over time, this may lead to muscle wasting, injuries, illness, and training intolerance [ 76 , 77 , 81 ].
For people involved in a general fitness program or simply interested in optimizing their health, recent research suggests protein needs may also be above the RDA. Phillips and colleagues [ 76 ], Witard et al.
In this respect, Morton and investigators [ 83 ] performed a meta-review and meta-regression involving 49 studies and participants and concluded that a daily protein intake of 1. In addition and in comparison to the RDA, non-exercising, older individuals 53—71 years may also benefit from a higher daily protein intake e.
Recent reports suggest that older muscle may be slower to respond and less sensitive to protein ingestion, typically requiring 40 g doses to robustly stimulate muscle protein synthesis [ 84 , 85 , 86 ]. Studies in younger individuals, however, have indicated that in the absence of exercise, a 20 g dose can maximize muscle protein synthesis [ 87 , 88 ] and if consumed after a multiple set workout consisting of several exercises that target large muscle groups a 40 g dose might be needed [ 89 ].
Consequently, it is recommended that athletes involved in moderate amounts of intense training consume 1. This protein need would be equivalent to ingesting 3—15 three-ounce servings of chicken or fish per day for a 50— kg athlete [ 78 ].
Although smaller athletes typically can ingest this amount of protein, on a daily basis, in their normal diet, larger athletes often have difficulty consuming this much dietary protein. Additionally, a number of athletic populations are known to be susceptible to protein malnutrition e.
and consequently, additional counseling and education may be needed to help these athletes meet their daily protein needs.
Overall, it goes without saying that care should be taken to ensure that athletes consume a sufficient amount of quality protein in their diet to maintain nitrogen balance.
Proteins differ based on their source, amino acid profile, and the methods of processing or isolating the protein undergoes [ 11 ]. These differences influence the availability of amino acids and peptides, which may possess biological activity e. For example, different types of proteins e.
Therefore, care should be taken not only to make sure the athlete consumes enough protein in their diet but also that the protein is high quality.
The best dietary sources of low fat, high quality protein are light skinless chicken, fish, egg whites, very lean cuts of beef and skim milk casein and whey while protein supplements routinely contain whey, casein, milk and egg protein.
In what is still an emerging area of research, various plant sources of protein have been examined for their ability to stimulate increases in muscle protein synthesis [ 77 , 97 ] and promote exercise training adaptations [ 98 ].
While amino acid absorption from plant proteins is generally slower, leucine from rice protein has been found to be absorbed even faster than from whey [ 99 ], while digestive enzymes [ ], probiotics [ ] and HMB [ ] can be used to overcome differences in protein quality. Preliminary findings suggest that rice [ 98 ] and pea protein [ ] may be able to stimulate similar changes in fat-free mass and strength as whey protein, although the reader should understand that many other factors dose provided, training status of participants, duration of training and supplementation, etc.
will ultimately impact these outcomes and consequently more research is needed. While many reasons and scenarios exist for why an athlete may choose to supplement their diet with protein powders or other forms of protein supplements, this practice is not considered to be an absolute requirement for increased performance and adaptations.
Due to nutritional, societal, emotional and psychological reasons, it is preferable for the majority of daily protein consumed by athletes to occur as part of a food or meal.
However, we recognize and embrace the reality that situations commonly arise where efficiently delivering a high-quality source of protein takes precedence. Jager and colleagues [ 11 ] published an updated position statement of the International Society of Sports Nutrition that is summarized by the following points:.
An acute exercise stimulus, particularly resistance exercise and protein ingestion both stimulate muscle protein synthesis MPS and are synergistic when protein consumption occurs before or after resistance exercise.
For building and maintaining muscle mass, an overall daily protein intake of 1. Higher protein intakes 2. Optimal doses for athletes to maximize MPS are mixed and are dependent upon age and recent resistance exercise stimuli. General recommendations are 0. The optimal time period during which to ingest protein is likely a matter of individual tolerance; however, the anabolic effect of exercise is long-lasting at least 24 h , but likely diminishes with increasing time post-exercise.
Rapidly digested proteins that contain high proportions of EAAs and adequate leucine, are most effective in stimulating MPS. Different types and quality of protein can affect amino acid bioavailability following protein supplementation; complete protein sources deliver all required EAAs.
The dietary recommendations of fat intake for athletes are similar to or slightly greater than dietary recommendations made to non-athletes to promote health. Maintenance of energy balance, replenishment of intramuscular triacylglycerol stores and adequate consumption of essential fatty acids are important for athletes, and all serve as reasons for an increased intake of dietary fat [ ].
For example, higher-fat diets appear to maintain circulating testosterone concentrations better than low-fat diets [ , , ]. Additionally, higher fat intakes may provide valuable translational evidence to the documented testosterone suppression which can occur during volume-type overtraining [ ].
In situations where an athlete may be interested in reducing their body fat, dietary fat intakes ranging from 0. This recommendation stems largely from available evidence in weight loss studies involving non-athletic individuals that people who are most successful in losing weight and maintaining the weight loss are those who ingest reduced amounts of fat in their diet [ , ] although this is not always the case [ ].
Strategies to help athletes manage dietary fat intake include teaching them which foods contain various types of fat so that they can make better food choices and how to count fat grams [ 2 , 33 ].
For years, high-fat diets have been used by athletes with the majority of evidence showing no ergogenic benefit and consistent gastrointestinal challenges [ ]. In recent years, significant debate has swirled regarding the impact of increasing dietary fat. While intramuscular adaptations result that may theoretically impact performance [ , ], no consistent, favorable impact on performance has been documented [ , ].
A variant of high-fat diets, ketogenic diets, have increased in popularity. This diet prescription leads to a greater reliance on ketones as a fuel source. Currently, limited and mixed evidence remains regarding the overall efficacy of a ketogenic diet for athletes.
In favor, Cox et al. Additionally, Jabekk and colleagues [ ] reported decreases in body fat with no change in lean mass in overweight women who resistance trained for 10 weeks and followed a ketogenic diet.
In light of the available evidence being limited and mixed, more human research needs to be completed before appropriate recommendations can be made towards the use of high fat diets for athletic performance. In addition to the general nutritional guidelines described above, research has also demonstrated that timing and composition of meals consumed may play a role in optimizing performance, training adaptations, and preventing overtraining [ 2 , 25 , 40 ].
In this regard, it takes about 4 h for carbohydrate to be digested and assimilated into muscle and liver tissues as glycogen. Consequently, pre-exercise meals should be consumed about four to 6 h before exercise [ 40 ].
This means that if an athlete trains in the afternoon, breakfast can be viewed to have great importance to top off muscle and liver glycogen levels. Research has also indicated that ingesting a light carbohydrate and protein snack 30 to 60 min prior to exercise e. This also serves to increase availability of amino acids, decrease exercise-induced catabolism of protein, and minimize muscle damage [ , , ].
Additionally, athletes who are going through periods of energy restriction to meet weight or aesthetic demands of sports should understand that protein intake, quality and timing as well as combination with carbohydrate is particularly important to maintain lean body mass, training effects, and performance [ 25 ].
Notably, this strategy becomes even more important if the athlete is under-fueled prior to the exercise task or is fasted vs. unfasted at the start of exercise [ 68 , 69 , ].
Following intense exercise, athletes should consume carbohydrate and protein e. This eating strategy has been shown to supersaturate carbohydrate stores prior to competition and improve endurance exercise capacity [ 2 , 40 ].
Thus, the type of meal, amount of carbohydrate consumed, and timing of eating are important factors to maximize glycogen storage and in maintaining carbohydrate availability during training while also potentially decreasing the incidence of overtraining.
The ISSN has adopted a position stand on nutrient timing in [ ] that has been subsequently revised [ 13 ] and can be summarized with the following points:. The importance of this strategy is increased when poor feeding or recovery strategies were employed prior to exercise commencement.
Consequently, when carbohydrate delivery is inadequate, adding protein may help increase performance, mitigate muscle damage, promote euglycemia, and facilitate glycogen re-synthesis.
Ingesting efficacious doses 10—12 g of essential amino acids EAAs either in free form or as a protein bolus in 20—40 g doses 0. However, the size 0. Post-exercise ingestion immediately-post to 2 h post of high-quality protein sources stimulates robust increases in MPS.
Similar increases in MPS have been found when high-quality proteins are ingested immediately before exercise. Vitamins are essential organic compounds that serve to regulate metabolic and neurological processes, energy synthesis, and prevent destruction of cells. Water-soluble vitamins consist of the entire complex of B-vitamins and vitamin C.
Since these vitamins are water-soluble, excessive intake of these vitamins are eliminated in urine, with few exceptions e. vitamin B6, which can cause peripheral nerve damage when consumed in excessive amounts. Table 1 describes the RDA, proposed ergogenic benefit, and summary of research findings for fat and water-soluble vitamins.
Research has demonstrated that specific vitamins possess various health benefits e. Alternatively, if an athlete is deficient in a vitamin, supplementation or diet modifications to improve vitamin status can consistently improve health and performance [ ].
For example, Paschalis and colleagues [ ] supplemented individuals who were low in vitamin C for 30 days and reported these individuals had significantly lower VO 2 Max levels than a group of males who were high in vitamin C.
Further, after 30 days of supplementation, VO 2 Max significantly improved in the low vitamin C cohort as did baseline levels of oxidative stress of oxidative stress. Furthermore, while optimal levels of vitamin D have been linked to improved muscle health [ ] and strength [ ] in general populations, research studies conducted in athletes generally fail to report on the ergogenic impact of vitamin D in athletes [ , ].
However, equivocal evidence from Wyon et al. The remaining vitamins reviewed appear to have little ergogenic value for athletes who consume a normal, nutrient dense diet. Finally, athletes may desire to consume a vitamin or mineral for various health non-performance related reasons including niacin to elevate high density lipoprotein HDL cholesterol levels and decrease risk of heart disease niacin , vitamin E for its antioxidant potential, vitamin D for its ability to preserve musculoskeletal function, or vitamin C to promote and maintain a healthy immune system.
Minerals are essential inorganic elements necessary for a host of metabolic processes. Minerals serve as structure for tissue, important components of enzymes and hormones, and regulators of metabolic and neural control.
Notably, acute changes in sodium, potassium and magnesium throughout a continued bout of moderate to high intensity exercise are considerable. In these situations, athletes must work to ingest foods and fluids to replace these losses, while physiological adaptations to sweat composition and fluid retention will also occur to promote a necessary balance.
Like vitamins, when mineral status is inadequate, exercise capacity may be reduced and when minerals are supplemented in deficient athletes, exercise capacity has been shown to improve [ ]. However, scientific reports consistently fail to document a performance improvement due to mineral supplementation when vitamin and mineral status is adequate [ , , ].
Table 2 describes minerals that have been purported to affect exercise capacity in athletes. For example, calcium supplementation in athletes susceptible to premature osteoporosis may help maintain bone mass [ ]. Increasing dietary availability of salt sodium chloride during the initial days of exercise training in the heat helps to maintain fluid balance and prevent dehydration.
Finally, zinc supplementation during training can support changes in immune status in response to exercise training. However, there is little evidence that boron, chromium, magnesium, or vanadium affect exercise capacity or training adaptations in healthy individuals eating a normal diet.
The most important nutritional ergogenic aid for athletes is water and limiting dehydration during exercise is one of the most effective ways to maintain exercise capacity. Before starting exercise, it is highly recommended that individuals are adequately hydrated [ ].
When one considers that average sweat rates are reported to be 0. For this reason, it is critical that athletes adopt a mind set to prevent dehydration first by promoting optimal levels of pre-exercise hydration.
Throughout the day and without any consideration of when exercise is occurring, a key goal is for an athlete to drink enough fluids to maintain their body weight. Next, athletes can promote optimal pre-exercise hydration by ingesting mL of water or sports drinks the night before a competition, another mL upon waking and then another — mL of cool water or sports drink 20—30 min before the onset of exercise.
Consequently, to maintain fluid balance and prevent dehydration, athletes need to plan on ingesting 0. This requires frequent every 5—15 min ingestion of 12—16 fluid ounces of cold water or a sports drink during exercise [ , , , , ].
Athletes should not depend on thirst to prompt them to drink because people do not typically get thirsty until they have lost a significant amount of fluid through sweat. Additionally, athletes should weigh themselves prior to and following exercise training to monitor changes in fluid balance and then can work to replace their lost fluid [ , , , , ].
During and after exercise, athletes should consume three cups of water for every pound lost during exercise to promote adequate rehydration [ ]. A primary goal soon after exercise should be to completely replace lost fluid and electrolytes during a training session or competition.
Additionally, sodium intake in the form of glucose-electrolyte solutions vs. only drinking water and making food choices and modifications added salt to foods should be considered during the rehydration process to further promote euhydration [ ].
Finally, inappropriate and excessive weight loss techniques e. are considered dangerous and should be prohibited. Sport nutritionists, dietitians, and athletic trainers can play an important role in educating athletes and coaches about proper hydration methods and supervising fluid intake during training and competition.
Educating athletes and coaches about nutrition and how to structure their diet to optimize performance and recovery are key areas of involvement for sport dietitians and nutritionists. Currently, use of dietary supplements by athletes and athletic populations is widespread while their overall need and efficacy of certain ingredients remain up for debate.
Dietary supplements can play a meaningful role in helping athletes consume the proper amount of calories, macro- and micronutrients. Dietary supplements are not intended to replace a healthy diet.
Supplementation with these nutrients in clinically validated amounts and at opportune times can help augment the normal diet to help optimize performance or support adaptations towards a training outcome. Sport dietitians and nutritionists must be aware of the current data regarding nutrition, exercise, and performance and be honest about educating their clients about results of various studies whether pro or con.
Currently, misleading information is available to the public and this position stand is intended to objectively rate many of the available ingredients. Additionally, athletes, coaches and trainers need to also heed the recommendations of scientists when recommendations are made according to the available literature and what will hopefully be free of bias.
We recognize that some ingredients may exhibit little potential to stimulate training adaptations or operate in an ergogenic fashion, but may favorably impact muscle recovery or exhibit health benefits that may be helpful for some populations. These outcomes are not the primary focus of this review and consequently, will not be discussed with the same level of detail.
Consequently, meal replacements should be used in place of a meal during unique situations and are not intended to replace all meals. Care should also be taken to make sure they do not contain any banned or prohibited nutrients. The following section provides an analysis of the scientific literature regarding nutritional supplements purported to promote skeletal muscle accretion in conjunction with the completion of a well-designed exercise-training program.
An overview of each supplement and a general interpretation of how they should be categorized is provided throughout the text. Table 3 summarizes how every supplement discussed in this article is categorized. However, within each category all supplements are ordered alphabetically.
For example, increases in body mass and lean mass are desired adaptations for many American football or rugby players and may improve performance in these activities.
In contrast, decreases in body mass or fat mass may promote increases in performance such as cyclists and gymnasts whereby athletes such as wrestlers, weightlifters and boxers may need to rapidly reduce weight while maintaining muscle mass, strength and power.
HMB is a metabolite of the amino acid leucine. It is well-documented that supplementing with 1. The currently established minimal effective dose of HMB is 1. To optimize HMB retention, its recommend to split the daily dose of 3 g into three equal doses of 1 g each with breakfast, lunch or pre-exercise, bedtime [ ].
From a safety perspective, dosages of 1. The effects of HMB supplementation in trained athletes are less clear with selected studies reporting non-significant gains in muscle mass [ , , ].
In this respect, it has been suggested by Wilson and colleagues [ 15 ] that program design periodized resistance training models and duration of supplementation minimum of 6 weeks likely operate as key factors.
Before and after each supplementation period, body composition and performance parameters were assessed. When HMB was provided, fat mass was significantly reduced while changes in lean mass were not significant between groups.
However, as reviewed by Jeukendrup b , sodium-dependent glucose transporter abundance and activity in animals is increased by a CHO-rich diet; furthermore, chronic exposure to higher CHO intakes by athletes, including exercise intake, increases gut tolerance, intestinal absorption, and muscle oxidation of CHO consumed during exercise Costa et al.
Combining glucose-based CHO sources with fructose transported in the intestine by GLUT5 increases total exogenous CHO oxidation during exercise, with rates as high as 1.
A range of sports drinks, gels, and confectionery is available to meet various targets, both in training and racing, around taste, practicality, balanced intake of fluid and CHO, inclusion of multiple transportable CHO sources, electrolyte replacement, and supplementation with caffeine, while other everyday foods and drinks may also be used.
Furthermore, the associated BM reduction may partially compensate for the disadvantages of dehydration. We recommend that athletes develop a personalized and practiced race plan that optimizes fluid and CHO status within the prevailing conditions and opportunities of each event.
Indeed, some recent elite marathons, including the Berlin event in which the most recent world record was set, have increased the frequency of feed zones every 2. A personalized drinking plan can be adjusted to all levels of runners, including recreational competitors who may drink in volumes exceeding their sweat rates and who should be warned about the dangers of developing hyponatremia Almond et al.
The specific needs of long-distance races raise potential new uses of sports foods and performance supplements, based on the specific physiological, biochemical, and central nervous system factors that limit performance in these races, as well as the opportunity to consume products within the event, at least for races of half marathon and longer.
Only a handful of the multitude of performance supplements marketed to athletes have a strong evidence base. Peeling et al. Indeed, the evidence base for these performance products relies on summaries of the general endurance sports literature McMahon et al.
While the known benefits of these strategies provide a benchmark against which the magnitude of any effects from other performance products should be compared, these also provide a potential confounder of the effectiveness of other performance supplements.
For example, a meta-analysis of a heterogeneous group of studies of caffeine supplementation and endurance performance Conger et al. This illustrates why potential interactions between concurrently used supplements or nutrition strategies are of high priority for scientific investigation and specific consideration when developing race plans or training uses Burke et al.
The efficacy of caffeine during endurance sports may be correlated with its role in masking fatigue Spriet, ; therefore, in situations in which another strategy reduces the onset or magnitude or fatigue, a smaller effect on performance is logical.
Other issues associated with caffeine or nitrate use in distance Athletics are noted in Tables 4 and 5.
Finally, the potential for enhanced glycogen storage following creatine supplementation Roberts et al. There are multiple and circular interactions between the hot environment and nutrition; exercise in the heat creates extra challenges in terms of increased rates of fluid loss and glycogen use Jentjens et al.
The performance and health challenges associated with racing in hot weather should be addressed by strategies, such as acclimatization, appropriate pacing, and precooling activities Racinais et al. Adjustment to race nutrition strategies, if practical, may also assist Table 2.
For example, a more aggressive approach to in-race hydration strategies to address greater fluid losses may be possible, while hyperhydration during the hours before a race via the consumption of large amounts of fluid together with an osmotic agent e.
The literature on the specific benefits of these strategies see Table 6 in high-performance running or racewalking scenarios is sparse; an investigation is required, including the assessment of potential disadvantages such as an increase in BM or a greater risk of gut disturbances.
In the meantime, athletes should practice the intended use of these strategies before implementing in a race. Although dietary surveys of Kenyan and Ethiopian runners have been limited to their home environments and training camps Beis et al.
Mooses, personal observations, Dec 10, A range of features, both consistent and in contrast to current sports nutrition guidelines, merit comment. Typical fluid choices include water 0. Meanwhile, meals are consumed soon after training sessions, and high-intensity track sessions are completed as a midmorning workout after breakfast.
Indeed, many concepts of periodizing CHO availability according to the needs of the session Burke et al. Although supplements are rarely used, data from observational studies Beis et al. Also of topical interest is the reported or suspected prevalence of acute or chronic periods of low energy availability among these athletes.
Notwithstanding artifacts in dietary survey methodology and calculations of energy availability Burke et al. Contributors to energy mismatches include cultural eating patterns e. Further study is needed to consolidate our understanding of the dietary practices of these highly successful athletes and how much they contribute to, or interfere with, optimal performance.
It is likely that practices include both helpful and harmful features, as well as accidental and intentional elements. As for any group of athletes, an audit of practices may identify the potential for performance improvement, but various practical and personal issues need to be taken into account.
Nearly years ago, Krogh and Lindhard reported that energy derived from the metabolic consumption of O 2 depends on whether fat or CHO is the primary source of carbon substrate. For example, increasing the respiratory quotient RQ from 0. In the D.
Dill lecture at the annual conference of the American College of Sports Medicine, Professor Ron Maughan identified the important implications of this finding for marathon performance; an increase in RQ improves metabolic efficiency by reducing the O 2 cost of running at a particular speed or permitting a higher speed for the same absolute V ˙ O 2.
This contradicts the conventional recommendation that endurance athletes should spare their finite CHO reserves by maximizing the use of fat as a substrate. However, it is supported by the findings of an increased O 2 cost of race walking at speeds related to race performance when rates of fat oxidation were markedly increased by adaptation to a ketogenic low CHO, high-fat diet Burke et al.
Theoretically, this could be provided by CHO g in the form of supercompensated muscle and liver glycogen stores supplemented by an aggressive approach to consuming CHO during the race.
However, even more subtle changes in RQ can be meaningful. For example, an athlete with a sustainable V ˙ O 2 of 3. Jones, personal observations May 6, ; Caesar, Further rigorous study of this concept is needed, but it may become part of the formula for further enhancement of distance running performance.
Distance athletes should adopt nutrition strategies that address specific physiological and biochemical factors that otherwise limit performance.
In-race nutrition is dependent on practicalities, such as the availability of aid stations as well as time and gut considerations of consuming CHO-containing fluids or other sports products.
Finally, several performance supplements, particularly caffeine and nitrate, could be considered for likely and potential benefits, respectively. All authors contributed to the preparation of this manuscript. The authors declare no conflicts of interest in the preparation of this review.
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Journal of the International Aging gracefully inspiration of Strtegies Sports nutrition strategies volume 15Article number: 38 Cite strategiies article. Metrics Pomegranate tarts recipes. Sports nutrition is ntrition constantly evolving sttategies with stratfgies of research papers published annually. Sports nutrition strategies, staying srategies with the relevant literature Sports nutrition strategies stratdgies difficult. This paper is an ongoing update of the sports nutrition review article originally published as the lead paper to launch the Journal of the International Society of Sports Nutrition in and updated in It presents a well-referenced overview of the current state of the science related to optimization of training and performance enhancement through exercise training and nutrition. Notably, due to the accelerated pace and size at which the literature base in this research area grows, the topics discussed will focus on muscle hypertrophy and performance enhancement. Refillable automotive fluids Sports nutrition strategies be mindful of good nutrition for Pomegranate tarts recipes and long-term health, stragegies need different strategies than nutrituon people to meet the demands of their sport. Athletes also need to develop good sports nutrition habits so they can perform at their best. Overall Healthy Eating 2. Sports Nutrition 3. Food and Recipe Ideas for Athletes 4.
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