Creatine Research

This systematic review and meta-analysis examined whether creatine supplementation provides additional body composition benefits beyond resistance training alone in adults under 50 years old. The review was preregistered and searched multiple databases, ultimately screening 1,694 records and including 12 studies in the quantitative analysis.

The meta-analysis found that creatine supplementation combined with resistance training significantly improved all three body composition outcomes compared to resistance training alone. Lean body mass increased by 1.14 kg, body fat percentage decreased by 0.88%, and body fat mass decreased by 0.73 kg. Subgroup analyses revealed no differences based on training status (trained vs. untrained) or concurrent carbohydrate ingestion.

The authors concluded that approximately 7 g or 0.3 g/kg body mass of creatine per day is likely sufficient to increase lean body mass by about 1 kg and reduce fat mass by about 0.7 kg more than resistance training alone. Concurrent carbohydrate intake did not enhance the hypertrophy benefits of creatine.

This 2024 systematic review and meta-analysis examined the effects of creatine monohydrate supplementation on cognitive function across 16 randomized controlled trials involving 492 participants aged 20.8-76.4 years. The study followed PRISMA 2020 guidelines and searched PubMed, Scopus, and Web of Science databases for RCTs published from 1993 to 2024.

Creatine supplementation significantly improved memory (SMD = 0.31, 95% CI: 0.18-0.44), attention time (SMD = -0.31, 95% CI: -0.58 to -0.03), and processing speed (SMD = -0.51, 95% CI: -1.01 to -0.01). However, no significant improvements were detected for overall cognitive function or executive function.

Subgroup analyses revealed that benefits were greater in diseased populations, individuals aged 18-60, and females. Duration of supplementation (short-term vs. long-term) did not significantly affect outcomes. The authors conclude that creatine may confer beneficial effects on specific cognitive domains but call for larger clinical trials to validate findings.

This 2024 systematic review and meta-analysis examined the combined effects of creatine supplementation and resistance training on muscle strength gains in adults under 50 years of age. The analysis included 23 studies with 447 male participants, 40 female participants, and 13 mixed-gender participants, searched across four databases through May 2024.

Creatine supplementation combined with resistance training significantly increased both upper-body strength (WMD = 4.43 kg, p < 0.001) and lower-body strength (WMD = 11.35 kg, p < 0.001) compared to resistance training alone. Males showed significant gains in both upper and lower-body strength, while females showed no significant gains.

A trend toward dose-dependent effects was observed for lower-body strength, with higher creatine doses showing greater improvements (p = 0.068). The findings confirm that creatine is an effective ergogenic aid for strength development when combined with resistance training, particularly in males under 50.

This systematic review and meta-analysis evaluated the efficacy of creatine supplementation for improving physical function in populations at risk of functional disability, including older adults and adults with chronic disease. The review searched four major databases from inception to November 2022 and identified 33 randomized controlled trials comprising 1,076 participants.

The primary outcome was sit-to-stand performance, which showed a moderate improvement with creatine supplementation (SMD 0.51, 95% CI: 0.01–1.00). A Bayesian analysis estimated a 66.7% posterior probability that creatine supplementation improves physical function. Secondary outcomes also favored creatine, with significant improvements in upper-body muscle strength, handgrip strength, and lean tissue mass (an increase of 1.08 kg).

This meta-analysis is particularly relevant because it focuses on clinical populations who stand to benefit most from functional improvements, including older adults and those with chronic conditions. The authors note that while the findings are promising, the overall quality of evidence was low to very low due to high risk of bias in many included studies, and they call for high-quality prospective RCTs to confirm these results.

This systematic review and meta-analysis examined the effects of creatine supplementation on memory in healthy individuals across 10 randomized controlled trials, with 8 included in the quantitative meta-analysis. Databases searched included PubMed, Web of Science, Cochrane Library, and Scopus through September 2021.

The overall analysis found that creatine supplementation significantly improved memory compared with placebo (SMD = 0.29, 95% CI: 0.04-0.53, p = 0.02). The most striking finding was the age-dependent effect: older adults aged 66-76 showed large benefits (SMD = 0.88, 95% CI: 0.22-1.55, p = 0.009), while younger adults aged 11-31 showed no significant improvement (SMD = 0.03, p = 0.72).

Creatine dose (ranging from 2.2-20 g/day), intervention duration (5 days to 24 weeks), sex, and geographical origin did not significantly influence outcomes. The findings suggest creatine supplementation has meaningful cognitive benefits particularly for aging populations.

This systematic review with meta-analysis examined the effects of creatine supplementation combined with resistance training on regional (site-specific) measures of muscle hypertrophy using direct imaging techniques such as MRI, CT, and ultrasound. Unlike many prior meta-analyses that relied on indirect measures like DEXA-derived lean mass, this study focused specifically on direct muscle size measurements.

Across 10 studies with 44 outcomes, the Bayesian analysis found a pooled standardized mean estimate of 0.11 (95% CrI: -0.02 to 0.25) favoring creatine supplementation, representing a very small positive effect. Multivariate analyses showed small benefits of 0.10–0.16 cm in muscle thickness for both upper and lower body regions. Moderator analyses suggested a slightly greater benefit in younger versus older adults.

The results confirm that creatine supplementation provides a genuine, albeit small, additive hypertrophic benefit when combined with resistance training. This is notable because direct imaging measures are considered more valid assessments of true muscle growth compared to whole-body composition methods.

Comprehensive meta-analysis examining creatine's effects on cognitive function across multiple studies.

Key findings:

• Significant improvements in short-term memory
• Enhanced reasoning and intelligence measures
• Stronger cognitive benefits in older adults (60+)
• More pronounced effects under stress or sleep deprivation
• Safe with no adverse cognitive effects reported

Mechanisms:

• Brain ATP buffering during high cognitive demand
• Neuroprotective effects against metabolic stress
• May support mitochondrial function in neurons

Clinical relevance:

Supports creatine use beyond athletic performance for cognitive health, particularly in aging populations and those under mental stress.

Comprehensive review of creatine's effects on brain function and neuroprotection.

Cognitive benefits:

• Improved memory and processing speed
• Enhanced executive function
• Better performance under sleep deprivation
• Reduced mental fatigue during demanding tasks

Neuroprotective mechanisms:

• Maintains brain ATP levels during stress
• Reduces oxidative damage to neurons
• Supports mitochondrial function
• May protect against neurodegenerative diseases

Populations that benefit most:

• Older adults
• Vegetarians/vegans (lower baseline brain creatine)
• Individuals under chronic stress
• Those with sleep disturbances

Clinical significance:

Expands creatine's applications beyond muscle performance to cognitive health and neuroprotection.

This systematic review examined the cognitive effects of creatine supplementation in healthy individuals. The researchers analyzed studies measuring various cognitive domains including memory, attention, and executive function.

The key finding was that creatine supplementation improved short-term memory and reasoning/intelligence, with the most pronounced effects occurring under conditions of stress such as sleep deprivation or mental fatigue.

The review suggests creatine's cognitive benefits stem from enhanced brain energy metabolism, as the brain is highly dependent on ATP.

Official position statement from the International Society of Sports Nutrition reviewing over 500 studies on creatine.

Key conclusions:

• Creatine monohydrate is the most effective ergogenic nutritional supplement
• Increases high-intensity exercise capacity by 10-20%
• Enhances lean body mass during training by 1-2 kg
• Safe for short and long-term use in healthy individuals
• No evidence of kidney damage, dehydration, or cramping

Dosing recommendations:

• Loading: 20g/day for 5-7 days (optional)
• Maintenance: 3-5g/day
• Timing: Any time, consistency matters most

Clinical significance:

Establishes creatine as the gold standard supplement for performance and muscle building with an excellent safety profile.

Large meta-analysis quantifying creatine's effect on lean tissue mass across 64 studies and 1,300+ participants.

Key findings:

• Average lean mass gain: +1.37 kg vs placebo
• Effect size: moderate to large (d=0.59)
• Benefits seen across age groups (young and elderly)
• Greater effects with longer supplementation duration
• Consistent results across different training protocols

Moderating factors:

• Training status (untrained may see larger relative gains)
• Duration of supplementation (longer = better)
• Type of training (resistance training amplifies effects)

Clinical significance:

Provides strong quantitative evidence for creatine's role in muscle building, supporting its A-tier evidence rating.

This meta-analysis examined 22 studies on creatine supplementation combined with resistance training. The researchers found consistent, significant improvements in strength and performance measures.

Creatine supplementation increased strength by an average of 8% more than placebo groups, with even larger effects (14%) on weightlifting performance measures like 1RM. The benefits were seen across different populations and training protocols.

This study established creatine as one of the most effective legal ergogenic aids for strength training.

This comprehensive meta-analysis examined the effects of creatine supplementation on body composition. The analysis included studies measuring lean body mass, fat mass, and total body mass changes.

Results showed consistent increases in lean body mass with creatine supplementation, beyond what was achieved with training alone. The effect was attributed to both increased water retention in muscle cells and actual increases in muscle protein.

The analysis helped establish creatine's role not just in performance but in changing body composition.