This article is excerpted from JISSN literature
Common questions and misconceptions about creatine supplementation:
what does the scientific evidence really show?
Frequently asked questions and misunderstandings about creatine supplementation:
What exactly does the scientific evidence show?
Supplement Creatine is a very popular way for athletes and individuals to improve muscle mass, performance and recovery. There is also increasing evidence that creatine supplementation can have a wide variety of beneficial effects on the elderly and patients. In addition, evidence-based studies have shown that creatine supplements are relatively tolerated, especially at recommended doses (i.e. 3-5 g/d or 0.1 g/kg/d). Although there are more than 500 peer-referenced publications involving creatine supplements, surprisingly, questions/misunderstandings about the effectiveness and safety of creatine supplements remain. These include but are not limited to:
1. Does creatine cause water retention?
2. Is creatine an anabolic steroid?
3. Does creatine cause renal damage/renal insufficiency?
4. Will creatine cause hair loss /bald?
5. Can creatine cause dehydration and muscle spasms ?
6. Is creatine harmful to children and adolescents?
7. Will creatine increase fat?
8. Is the creatine "loading stage" required?
9. Is creatine beneficial to the elderly?
10. Is creatine only useful for resistance/explosion training?
11. Is creatine only effective for men?
12. Are other forms of creatine similar or better than creatine monohydrate? Is creatine stable in solution/beverage?
To answer these questions, an internationally renowned team of research experts was established to conduct an evidence-based scientific evaluation of the literature on creatine supplementation.
▍Creatine causes water retention?
The misunderstanding that creatine increases body water may be due to early studies that creatine intake 20 grams per day, for 6 consecutive days, is related to water retention. The most common side effect of creatine appears to be water retention during the early stages (the first few days).
Creatine is an osmotic active substance. Therefore, in theory, an increase in the body's creatine content may lead to an increase in water retention. Creatine enters the muscles through the blood circulation through the sodium-dependent creatine transporter. Since transport involves sodium, water will also be absorbed by the muscles to help maintain permeability within the cells. However, , considering the activity of sodium potassium pump , creatine supplementation is unlikely to significantly affect the intracellular sodium concentration.
In summary, while there is some evidence that creatine supplementation increases water retention, mainly attributed to increased intracellular volume; in the short term, several other studies have shown that over a longer period of time, it does not alter the systemic moisture (intracellular or extracellular) relative to muscle mass. Therefore, supplementation with creatine may not cause water retention .
▍Is creatine an anabolic steroid?
Anabolic steroids are artificially synthesized testosterone, a androgen that can be produced endogenously in both men and women, used in combination with resistance training to enhance muscle mass and strength by increasing muscle protein synthesis (MPS). The increase in MPS is due to the ability of testosterone to enter muscle cells, bind to androgen receptors in the cell, and increase the expression of various muscle-specific genes.
creatine is converted to creatine phosphate (PCr), regulated by creatine kinase (CK) in the muscles and is used to produce intracellular adenosine triphosphate (ATP). creatine supplementation can increase ATP's ability and energy generated during heavy anaerobic-related exercises, which may increase muscle strength, repetitions and exercise volume, promoting muscle performance and hypertrophy during training.
Although the physiological and manifestations of anabolic steroids and creatine are similar, their mechanisms of action and legal classification are different.Anabolic steroids are drugs with chemical structures that are different from creatine. They are controlled substances of C Schedule III regulated by FDA and are regulated and bound by the Drug Control Regulations (CSA) established by the U.S. Drug Administration (DEA).
On the other hand, creatine, like many other dietary supplements, complies well with the provisions of the Dietary Supplement Health and Education Act (DSHEA) of 1994, complies with the U.S. federal regulations, and the Drug Production Quality Management Code (GMP) . It is illegal to own and use anabolic steroids without a doctor's prescription. However, creatine intake is legal.
In short, because creatine has a completely different chemical structure, it is not an anabolic steroid.
▍Does creatine cause renal damage/renal insufficiency?
Questions and concerns about creatine supplementation and renal damage/renal insufficiency are common. As far as misinformation is common in the field of sports nutrition, the concept that creatine supplementation can lead to renal injury/renal insufficiency is concerned, which may be second only to the misunderstanding that protein supplementation and high habitual protein intake can lead to renal injury.
In skeletal muscle , both creatine and creatine phosphate (PCr) are degraded to creatinine by non-enzymatically, and then exported to the blood and excreted from the body with urine. A healthy kidney filters creatinine, otherwise the creatinine in the blood will increase. Therefore, serum creatinine levels can be used as an alternative indicator of renal function. However, the amount of creatinine in the blood is associated with muscle mass (i.e., the blood creatinine in men is higher than that in women) and dietary creatine and creatinine intake. Creatinine in both the blood and urine can be increased by intake of creatine and foods containing creatine (such as meat). Creatine is not usually present in the urine, but can reach very high levels (10 g/day) during creatine supplementation.
There seems to be an unproven view that if the kidney is "forced" to excrete creatinine or creatine above normal levels, some form of kidney "overload" will occur, resulting in kidney damage and/or renal insufficiency. In fact, is unlikely to reflect a decrease in renal function due to a brief increase in blood or urinary creatine or creatinine caused by creatine supplementation. In addition, caution must be taken for those who consume large amounts of meat or supplement with creatine when using blood creatinine and estimated creatinine clearance/ glomerular filtration rate .
Be cautious when taking any dietary supplements or medications. Survey data show that creatine supplementation is used in athletes and other sports individuals. Even if only 8% of the sports population are estimated to use creatine supplements, it also indicates that thousands of people have used creatine over the past few decades. If the link between creatine supplementation and renal health is effective, renal damage/renal insufficiency is expected to increase in low-risk (i.e., young, physically healthy) individuals since the far-reaching study published by Harris et al. However, after nearly 30 years of post-market monitoring, thousands of risk exposures and multiple clinical trials, there is no such evidence.
In summary, experimental and controlled studies have shown that in healthy individuals, if creatine is intake at the recommended dose, it will not cause renal damage and/or renal insufficiency.
▍Creatine causes hair loss/baldness?
Some hormone changes, especially dihydrotestosterone (DHT), are associated with the occurrence of some (but not all) hair loss; the theory of creatine supplementation leading to hair loss/baldness gained some momentum, and this potential link remains a common misconception.
DHTh is a metabolite of testosterone, formed when 5α-reductase converts free testosterone into DHT. In men, DHT can bind to androgen receptors in susceptible hair follicles, causing hair follicles to atrophy and ultimately lead to hair loss. Although creatine supplementation may upregulate 5α-reductase activity in these men (which may lead to an increase in DHT formation), no studies have reported human hair loss/baldness.
To date, 12 other studies have investigated the effects of creatine supplementation (dose range from 3-25 g/d, lasting 6 days to 12 weeks) on testosterone.Two studies reported a slight and physiologically insignificant increase in total testosterone after 6 and 7 days of supplementation, while the remaining 10 studies reported no changes in testosterone concentrations. In five of the studies, free testosterone used by the body to produce DHT was also measured, with no increase found.
In summary, the current evidence of does not suggest that creatine supplementation increases total testosterone, free testosterone, dihydrotestosterone (DHT) or causes hair loss/baldness.
▍Creatine causes dehydration and muscle cramps?
In the early 20th century, due to limited data and mainly based on speculation, the American Society of Sports Medicine (ACSM) recommended that people who control weight and exercise vigorously or exercise in hot environments should avoid using creatine supplements. The principle of creatine supplementation may lead to dehydration and muscle spasms is based on the premise that creatine is an osmotic active substance that is mainly found in skeletal muscle and can change the distribution of fluid throughout the body by preferentially increasing intracellular water uptake and retention, especially in the short term.
In the case of body loss, such as severe sweating caused by exercise and/or ambient temperature rise, intracellular fluids may theoretically be unfavorable for thermal regulation and lead to extracellular dehydration, electrolyte imbalance and muscle spasms or other heat-related musculoskeletal problems.
Greenwood et al. monitored the injury rate of NCAA-IA college football players with hot and humid environmental conditions. Throughout the season, participants chose to receive creatine or a placebo for sports drinks. creatine has fewer cramps, heat stroke, dehydration, muscle tension, muscle strain and total damage than those who do not use creatine. Non-contact joint injury, contact injury, illness, absence of training due to injury, and losing the game this season did not differ between groups. In clinical settings, hemodialysis patients who often report muscle cramps are provided with creatine 5 minutes before hemodialysis. creatine supplementation reduces the frequency of symptomatic muscle cramps . These beneficial effects of creatine can be explained as liquid distribution and electrolyte imbalance, as previously described.
In summary, experimental and clinical studies did not confirm the view that creatine supplementation causes dehydration and muscle spasms .
▍Is creatine harmful to children and adolescents?
In 2001, Unnithan and his colleagues first proposed the physiological principles of potential energic effects of creatine supplementation in children and adolescents, which laid a solid foundation for future application of creatine in young athletes. Recently, in a review of the safety of creatine supplementation in adolescents, Jagim et al. summarized several studies that confirmed the effectiveness of creatine supplementation in different groups of adolescent athletes without finding adverse effects.
From a clinical point of view, creatine supplements have potential health benefits and minimal side effects in young people. However, the strongest evidence for creatine safety may be the latest classification of creatine by the FDA in late 2020—GRAS. This classification shows that currently the scientific data on creatine safety of is sufficient and has been unanimously agreed by qualified experts to determine that creatine is safe under the conditions of its intended use. Although babies and toddlers are excluded from GRAS, this is still for older children and adolescents .
Most dietary supplement research data show that relatively high percentages of young and adolescent athletes currently or previously used creatine. In addition, in a sample of young German athletes (14-18 years) with Olympic level, 12% of participants reported creatine supplementation. Therefore, these trends require further research to determine whether creatine supplements, both short-term and long-term, are safe for children and adolescents.
To sum up, based on limited evidence, creatine supplements appear to be safe and have potential benefits for children and adolescents.
▍ Will creatine increase fat?
Creatine supplementation increases fat mass, which is a question worth paying attention to among people who exercise. Maybe some people have gained weight through creatine supplementation. Becque et al. found that there was no change in fat mass after six weeks of supplementation and resistance training. In addition, supplementing creatine during the 8-week rugby season had no effect on fat mass.
Some people may think that 8 weeks or less creatine supplementation is not enough to draw a clear conclusion about the effect of creatine on fat mass. Gualano et al. evaluated the effect of creatine supplementation (24 weeks) in older women with resistance training. The results showed that creatine had no effect on fat mass. Candow et al. studied the effect of creatine supplementation on the elderly (50-71 years old) during the 32-week treatment period. Over time, lean body weight and strength will increase, while fat volume will decrease. From a clinical point of view, after two consecutive periods of creatine (0.1 g/kg/day) in children with acute lymphoblastic leukemia, the fat mass decreased significantly after two consecutive periods of 16 weeks. In contrast, children without creatine consumed increased fat. In two studies involving postmenopausal women, Lobo et al. found that there was no absolute or relative body fat changes after one year of low-dose creatine supplementation. In addition, two years of creatine supplementation had no effect on fat mass.
Recently, Forbes et al. conducted a systematic review of randomized controlled trials and meta-analysis of , which involved the effect of creatine supplementation-bound resistance training on fat mass in older people (≥50 years old). A total of 609 participants were included in the 19 studies. Participants who supplemented creatine decreased their body fat rates faster. There was no significant difference in absolute fat reduction; however, the creatine group lost about 0.5 kg of fat more than the placebo group.
In short, In different groups, creatine supplementation will not increase fat mass.
▍Does creatine "loading stage" be required?
creatine "loading" is defined as oral creatine for 5-7 days, with a dose of 20-25g/d, which is often divided into small doses (4-5 times, 5g/time). Creatine "loading" can also be determined based on body weight, for example, within 5-7 days, 0.3 g/kg/d. The "loading" phase of creatine supplementation is followed by the "maintenance" phase, usually 3-5g/d.
A common misconception about creatine supplementation is that individuals must "load" creatine to increase storage of intramuscular creatine before they can generate energy-enhancing benefits. However, compared with placebo, the lower daily creatine supplementation (3-5g/d) of has been fully recognized by the scientific literature in increasing intramuscular creatine storage, with greater improvements in muscle mass, performance and recovery. These creatine supplementation strategies without loading stages delay the maximum storage time of muscle creatine. Therefore, it is currently recommended that each person consume at least 3-5g of creatine per day for 4 weeks to achieve similar skeletal muscle saturation levels .
Determine which creatine supplementation strategy is preferred, which may depend on the individual's target . For example, if athletes want to maximize creatine supplementation in a very short period of time (30 days), it is recommended to adopt a creatine "load" strategy. However, if an athlete or trainer plans to consume creatine for a long time (30 days), or to avoid potential weight gain that may occur during creatine “loading”, a creatine “maintenance period” strategy will be a viable option. Athletes who are undergoing the creatine loading phase (i.e. 20g/d) should emphasize a smaller dose strategy throughout the day (less than or equal to 10g per time), as dosages of exceeding 10g may potentially cause gastrointestinal discomfort (diarrhea).
In short, there is increasing evidence that does not require a "load" phase. Lower daily creatine supplementation doses (i.e. 3-5 g/day) can effectively increase in intramuscular creatine reserves and increase muscle and muscle performance/recovery.
▍Is creatine beneficial to the elderly?
Perhaps, age-related sarcopenia is one of the most promising situations to benefit from creatine supplementation.Although resistance training is considered the cornerstone of the treatment of sarcopenia, there is growing evidence that creatine supplementation can enhance the anabolic environment generated by resistance training, thereby reducing various indicators of sarcopenia.
creatine supplementation can increase function (strength, daily life activities, delayed fatigue) and muscle mass in the elderly. However, the literature shows that using creatine alone (i.e., without accompanying resistance training) is unlikely to achieve substantial improvements in muscle strength and functional performance, although it does improve some parameters of muscle fatigue. Similarly, most studies failed to show the beneficial effect of chronic creatine supplementation alone (≥30 days) on lean body weight.
In contrast, a large amount of evidence suggests that creatine supplementation enhances hypertrophy responses to resistance training in young people, which has been confirmed by three systematic reviews and meta-analysis and extended to the elderly. The fact that creatine is more effective in combining training stimulation shows that the main mechanism of creatine is its ability to enhance training volume and/or intensity, which may affect muscle protein dynamics, growth factor , satellite cell , inflammation and/or oxidative stress , ultimately leading to greater skeletal muscle adaptability.
Regarding bone aging, emerging research over the past decade shows that there are some benefits to supplementing creatine. For example, compared with placebo, healthy elderly men (50 years old) who supplemented creatine and underwent systemic resistance training for 10-12 weeks, increased bone mineral content of upper limbs and decreased bone resorption. Recently, Chilibeck et al. showed that 52 weeks of creatine supplementation and supervised systemic resistance training can reduce the bone mineral loss rate of women with hips after menopause hips compared to placebo . From a clinical and healthy aging perspective, recommends combining creatine supplementation with resistance training to produce the greatest adaptability in the elderly.
In short, there is increasing evidence that supplements with creatine, especially when combined with exercise, are beneficial to the musculoskeletal and performance in the elderly.
▍Is creatine useful only for resistance/explosion training?
Although theoretically speaking, creatine supplementation is mainly beneficial to athletes participating in high-intensity intermittent resistance/explosion training, there is increasing evidence that creatine supplementation may also have a beneficial effect on other activities.
First, creatine combined with carbohydrate or carbohydrate and protein has been reported to promote larger muscle glycogen storing than supplementing carbohydrate alone, promotes greater muscle glycogen storing . Glycogen supplementation is important for promoting recovery and preventing overtraining during intensive training, and creatine supplementation can help athletes who consume large amounts of glycogen in training and/or performance (e.g., sports events) maintain optimal glycogen levels.
Second, there is evidence that supplementation of creatine can reduce muscle damage and/or enhance recovery after strenuous exercise . Furthermore, there is evidence that people who consume creatine in their diet experience less muscle damage, inflammation and muscle soreness during 30 km running and 4 weeks of intensive training. Therefore, creatine supplementation can help athletes recover from high-intensity exercise and/or tolerate high-intensity training to a greater extent.
Third, there is evidence that athletes who supplement creatine during training will suffer less musculoskeletal injury, faster recovery from the injury, and less muscle atrophy after fixation. Whether this is due to greater resistance to the injury and/or ability to recover from the injury is unclear.
Fourth, it is reported that creatine supplementation (including or not including glycerol ) can help athletes consume excessive water, thereby improving athletes' tolerance for exercise at high temperatures . Therefore, supplementing creatine can reduce the risk of heat-related diseases when athletes train and/or compete in hot and humid environments. Finally, there is evidence in animal models that creatine supplements have neuroprotective effects and can alleviate the severity of spinal cord injury, cerebral ischemia, and concussion/traumatic brain injury .This evidence is so compelling that the International Society of Sports Nutrition ISSN recommends that athletes engaged in sports that may cause concussion and/or spinal cord injuries take creatine to exert their neuroprotective effects.
To sum up, in addition to resistance/explosion training, also has many sports that can benefit from creatine supplementation.
▍Is creatine effective only for men?
creatine dynamics may vary between healthy men and women. Women may have higher intramuscular creatine concentrations, which may be due to lower skeletal muscle mass. Higher resting intramuscular creatine concentrations in women (based on the upper limit of intramuscular creatine storage) may help explain some studies showing a weaker effect of female responsiveness and/or performance.
In performance-based studies, the effects of hormone-related changes in creatine kinetics have been largely ignored. Specifically, creatine supplementation may be particularly important during menstruation, pregnancy, postpartum, menopause, and postmenopausal . Creatine kinase, as well as enzymes associated with creatine synthesis, are affected by estrogen and progesterone.
In preclinical animal studies, creatine supplementation during pregnancy has been shown to have a protective effect on fetal death and organ damage associated with onset hypoxia . Creatine supplementation during pregnancy has been shown to enhance creatine uptake by nerve cells in animal offspring and support the integrity of mitochondrial , thereby reducing brain damage caused by suffocation during delivery.
Although no human studies assess the effects of creatine supplementation during pregnancy, creatine can provide a safe, low-cost nutritional intervention to reduce postpartum complications associated with cellular energy consumption. This may be even more important if women are vegetarians or are unable to eat meat due to nausea or taste preference (meat contains about 0.7 grams of creatine per 6 ounces).
It is reported that women's brain (frontal lobe) have lower creatine levels. Since creatine supplementation increases creatine concentrations in the brain, especially in women, this may support reports on 's effects on reducing symptoms of depression and improving traumatic brain injury . Creatine supplementation seems to be a viable option, improves muscle mass and performance in postmenopausal women. In addition, creatine may also be beneficial for postmenopausal women's bones, if combined with resistance training . Even without the stimulation of resistance training, there is some evidence that supplementing creatine is still beneficial. For example, in older women, acute creatine supplementation (0.3 g/kg/day for 7 days) significantly improved lower limb body performance (sit-to-stop trial), as well as fat-free mass and upper and lower body strength compared to placebo.
In short, there is increasing evidence that creatine supplements have the potential to become a multi-factor therapeutic intervention that runs through the life cycle of in women with few side effects.
▍Is other forms of creatine similar or better than creatine monohydrate? Is creatine stable in solution/beverage?
study shows that oral creatine monohydrate (3-5 g/d) can increase the blood concentration of creatine within 3-4 hours after intake, thereby promoting creatine through diffusion and creatine transporter into tissues. Furthermore, it has been determined that about 99% of oral creatine monohydrate is either absorbed by tissues or excreted from urine in the form of creatine through normal digestion.
Many different forms of creatine (creatine, complex of creatine and other nutrients, creatine dipeptides, etc.) have been sold as a more effective source than creatine monohydrate. However, no peer-reviewed papers have shown that intake of equal amounts of creatine or other forms of creatine, or trace amounts of creatine (25-50 mg) contained in creatine serum and beverages can increase creatine storage in muscles more than creatine monohydrate. In fact, most studies have shown that intake of these other forms of creatine has a less physiological effect on intramuscular creatine storage and/or performance than creatine monohydrate.
creatine monohydrate crystallizes from water to monoclinic prism, and each molecule of creatine contains one molecule of crystallization water .Creatine monohydrate is then dried at about 100°C to remove the water from the crystals, producing anhydrous creatine (100% creatine). Except for anhydrous creatine, creatine monohydrate powder has the highest creatine content (87.9%). Creatine monohydrate is usually used to study safety and efficacy, so this is also the recommended source of creatine monohydrate in dietary supplements.
creatine monohydrate powder is very stable and has no sign of degradation to creatinine even at higher storage temperatures. However, creatine is unstable in solution because intramolecular cyclization converts creatine to creatine, especially at higher temperatures and lower pH values. Therefore, less than 1% of creatine monohydrate is decomposed into creatinine during the digestion process, and creatine is absorbed by tissues or excreted from the body in urine after intake. Furthermore, since creatine is an amphoteric amino acid, it is insoluble in water. creatine lacks solubility and stability in solution , which is why creatine is mainly sold in powder form, while stable beverages containing physiologically effective doses of creatine (3-5 grams each time) have not been successful.
In short, although some forms of creatine may be more soluble in liquids than creatine monohydrate, evidence-based studies clearly show that creatine monohydrate is the best choice.
▍Conclusion
- Supplementation of creatine does not always lead to water retention.
- Creatine is not an anabolic steroid.
- In healthy individuals, creatine is consumed at the recommended dose, which will not cause renal damage and/or renal insufficiency.
- Most of the available evidence does not support the link between creatine supplementation and hair loss/baldness.
- Supplementation of creatine will not cause dehydration or muscle cramps.
- creatine supplements are generally safe and have potential benefits for children and adolescents.
- Supplementation of creatine will not increase fat.
- A small amount of creatine supplementation per day (3-5g or 0.1g/kg) is effective. Therefore, the creatine "loading" phase is not required.
- In the elderly, creatine supplementation combined with resistance training produces the vast majority of musculoskeletal and performance benefits. Supplementing creatine alone can provide some muscle and exercise benefits for older people.
- creatine supplementation is beneficial for various sports and sports activities.
- Supplementation of creatine has many benefits for a woman's life cycle.
- Other forms of creatine are not better than creatine monohydrate.
