Effects of Creatine Supplementation on Exercise Performance in the Heat in Endurance-Trained Humans (original) (raw)
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Creatine is one of the most popular and widely researched natural supplements. The majority of studies have focused on the effects of creatine monohydrate on performance and health; however, many other forms of creatine exist and are commercially available in the sports nutrition/supplement market. Regardless of the form, supplementation with creatine has regularly shown to increase strength, fat free mass, and muscle morphology with concurrent heavy resistance training more than resistance training alone. Creatine may be of benefit in other modes of exercise such as high-intensity sprints or endurance training. However, it appears that the effects of creatine diminish as the length of time spent exercising increases. Even though not all individuals respond similarly to creatine supplementation, it is generally accepted that its supplementation increases creatine storage and promotes a faster regeneration of adenosine triphosphate between high intensity exercises. These improved outcomes will increase performance and promote greater training adaptations. More recent research suggests that creatine supplementation in amounts of 0.1 g/kg of body weight combined with resistance training improves training adaptations at a cellular and sub-cellular level. Finally, although presently ingesting creatine as an oral supplement is considered safe and ethical, the perception of safety cannot be guaranteed, especially when administered for long period of time to different populations (athletes, sedentary, patient, active, young or elderly).
Creatine supplementation with specific view to exercise/sports performance: an update
Journal of the International Society of Sports Nutrition, 2012
Creatine is one of the most popular and widely researched natural supplements. The majority of studies have focused on the effects of creatine monohydrate on performance and health; however, many other forms of creatine exist and are commercially available in the sports nutrition/supplement market. Regardless of the form, supplementation with creatine has regularly shown to increase strength, fat free mass, and muscle morphology with concurrent heavy resistance training more than resistance training alone. Creatine may be of benefit in other modes of exercise such as high-intensity sprints or endurance training. However, it appears that the effects of creatine diminish as the length of time spent exercising increases. Even though not all individuals respond similarly to creatine supplementation, it is generally accepted that its supplementation increases creatine storage and promotes a faster regeneration of adenosine triphosphate between high intensity exercises. These improved outcomes will increase performance and promote greater training adaptations. More recent research suggests that creatine supplementation in amounts of 0.1 g/kg of body weight combined with resistance training improves training adaptations at a cellular and sub-cellular level. Finally, although presently ingesting creatine as an oral supplement is considered safe and ethical, the perception of safety cannot be guaranteed, especially when administered for long period of time to different populations (athletes, sedentary, patient, active, young or elderly).
Analysis of the efficacy, safety, and regulatory status of novel forms of creatine
Amino Acids, 2011
Creatine has become one of the most popular dietary supplements in the sports nutrition market. The form of creatine that has been most extensively studied and commonly used in dietary supplements is creatine monohydrate (CM). Studies have consistently indicated that CM supplementation increases muscle creatine and phosphocreatine concentrations by approximately 15-40%, enhances anaerobic exercise capacity, and increases training volume leading to greater gains in strength, power, and muscle mass. A number of potential therapeutic benefits have also been suggested in various clinical populations. Studies have indicated that CM is not degraded during normal digestion and that nearly 99% of orally ingested CM is either taken up by muscle or excreted in urine. Further, no medically significant side effects have been reported in literature. Nevertheless, supplement manufacturers have continually introduced newer forms of creatine into the marketplace. These newer forms have been purported to have better physical and chemical properties, bioavailability, efficacy, and/or safety profiles than CM. However, there is little to no evidence that any of the newer forms of creatine are more effective and/or safer than CM whether ingested alone and/or in combination with other nutrients. In addition, whereas the safety, efficacy, and regulatory status of CM is clearly defined in almost all global markets; the safety, efficacy, and regulatory status of other forms of creatine present in today's marketplace as a dietary or food supplement is less clear.
Dietary Creatine Supplementation and Exercise Performance: Why Inconsistent Results?
Canadian Journal of Applied Physiology, 2002
Over the past few years there has been considerable interest in both the use of creatine (Cr) supplementation by athletes and the documentation of its effects by scientists. Some believe that this nitrogen-containing compound found in meat and fish has a performance-enhancing capability as important for brief intense exercise efforts as dietary carbohydrate is for activities where glycogen supplies limit performance. The mechanisms thought to be responsible for any ergogenic effect of acute (few d) Cr supplementation include: increased stores of muscle phosphocreatine (PCr), faster regeneration of PCr during exercise recovery, enhanced adenosine triphosphate (ATP) production from glycolysis secondary to increased hydrogen ion buffering, and/or possible shortened post contraction muscle relaxation time. With chronic (wk & mo) supplementation when combined with strength training, Cr may alter muscle protein metabolism directly (via decreasing protein breakdown or increasing synthesis)...
Journal of the International Society of Sports Nutrition, 2017
Creatine is one of the most popular nutritional ergogenic aids for athletes. Studies have consistently shown that creatine supplementation increases intramuscular creatine concentrations which may help explain the observed improvements in high intensity exercise performance leading to greater training adaptations. In addition to athletic and exercise improvement, research has shown that creatine supplementation may enhance post-exercise recovery, injury prevention, thermoregulation, rehabilitation, and concussion and/or spinal cord neuroprotection. Additionally, a number of clinical applications of creatine supplementation have been studied involving neurodegenerative diseases (e.g., muscular dystrophy, Parkinson's, Huntington's disease), diabetes, osteoarthritis, fibromyalgia, aging, brain and heart ischemia, adolescent depression, and pregnancy. These studies provide a large body of evidence that creatine can not only improve exercise performance, but can play a role in pr...
Effects of Creatine Supplementation on Exercise Performance
Sports Medicine, 1999
While creatine has been known to man since 1835, when a French scientist reported finding this constituent of meat, its presence in athletics as a performance enhancer is relatively new. Amid claims of increased power and strength, decreased performance time and increased muscle mass, creatine is being hailed as a true ergogenic aid. Creatinine is synthesised from the amino acids glycine, arginine and methionine in the kidneys, liver and pancreas, and is predominantly found in skeletal muscle, where it exists in 2 forms. Approximately 40% is in the free creatine form (Crfree), while the remaining 60% is in the phosphorylated form, creatine phosphate (CP). The daily turnover rate of approximately 2g per day is equally met via exogenous intake and endogenous synthesis. Although creatine concentration (Cr) is greater in fast twitch muscle fibres, slow twitch fibres have a greater resynthesis capability due to their increased aerobic capacity. There appears to be no significant difference between males and females in Cr, and training does not appear to effect Cr. The 4 roles in which creatine is involved during performance are temporal energy buffering, spatial energy buffering, proton buffering and glycolysis regulation. Creatine supplementation of 20g per day for
International Society of Sports Nutrition position stand: creatine supplementation and exercise
Journal of the International Society of Sports Nutrition, 2007
A Position Statement and Review of the Literature Position Statement: The following nine points related to the use of creatine as a nutritional supplement constitute the Position Statement of the Society. They have been approved by the Research Committee of the Society. 5. At present, creatine monohydrate is the most extensively studied and clinically effective form of creatine for use in nutritional supplements in terms of muscle uptake and ability to increase high-intensity exercise capacity. 6. The addition of carbohydrate or carbohydrate and protein to a creatine supplement appears to increase muscular retention of creatine, although the effect on performance measures may not be greater than using creatine monohydrate alone. 7. The quickest method of increasing muscle creatine stores appears to be to consume ~0.3 grams/kg/day of creatine monohydrate for at least 3 days followed by 3-5 g/ d thereafter to maintain elevated stores. Ingesting smaller amounts of creatine monohydrate (e.g., 2-3 g/d) will increase muscle creatine stores over a 3-4 week period, however, the performance effects of this method of supplementation are less supported. 8. Creatine products are readily available as a dietary supplement and are regulated by the U.S. Food and Drug Administration (FDA). Specifically, in 1994, U.S. President Bill Clinton signed into law the Dietary Supplement Health and Education Act (DSHEA). DSHEA allows manufacturers/companies/brands to make structure-function
The Use of Creatine in Sport: An Educational Article
Clinics in Nursing (e-ISSN: 2835-8147) , 2023
Many sports and strenuous exercises are associated with some degree of muscle damage, pain and fatigue that can lead to poor athletic progress, therefore the need for recovery speeding methods has been increasingly demanded. The use of performance enhancing nutritional supplements to improve athletic performance has been increasing during the previous decades. Supplementation with vitamins and minerals in excess of recommended daily allowances has been increasingly reported to have no effect on muscle mass or athletic performance, and the need to identify evidence-based sport supplements has been increasingly demanded. The aim of this paper is to provide an overview of the use of creatine in sport research progress.
The nutritional biochemistry of creatine
The Journal of Nutritional Biochemistry, 1997
Creatine is a naturally occurring compound that is synthesized endogenously and is present in a meat eaters diet. It is stored in abundance in skeletal muscle, where it exists in free and phosphorylated forms and plays a pivotal role in maintaining a high adenosine triphosphate:adenosine diphosphate ratio during intense contraction. Fatigue development during short-term maximal exercise has been associated with the inability of skeletal muscle to maintain this ratio, at least partly because of phosphocreatine depletion. Ingestion of creatine monohydrate in solution at a rate of 20 g/day for 5 to 6 days has been shown to increase muscle total creatine concentration by approximately 25 mmobkg dry mass in man, but the variation between subjects is large. After this initial loading phase, muscle stores can be maintained by ingesting 2 g/day. A positive relationship has since been demonstrated between muscle creatine uptake and improvements in pe$ormance during repeated bouts of maximal exercise and rates of phosphocreatine resynthesis during recovery from maximal exercise. The mechanism by which improvements in maximal exercise pe$ormance are achieved following creatine ingestion possibly relates to an increase in phosphocreatine concentration, specifically in Type II muscle fibres, maintaining adenosine triphosphate resynthesis during exercise. Recently, muscle creatine accumulation has been shown to be substantially increased by combining creatine supplementation with carbohydrate ingestion, elevating muscle creatine concentration in all subjects close to the upper limit of 160 mmobkg dm. Creatine supplementation should be viewed as a significant development in sports-related nutrition.