Creatine Supplementation for Muscle Growth: A Scoping Review of Randomized Clinical Trials from 2012 to 2021

Abstract

Creatine supplementation is the most popular ergonomic aid for athletes in recent years and is used for improving sport performance and muscle growth. However, creatine supplementation is not always effective in all populations. To address these discrepancies, numerous studies have examined the use of creatine supplementation for muscle growth. This scoping review aimed to investigate the effects of creatine supplementation for muscle growth in various populations, in which Arksey and O’Malley’s scoping review framework is used to present the findings. For this study, we performed a systematic search of the PubMed, Embase, and Web of Science databases for theses and articles published between 2012 and 2021. A manual search of the reference lists of the uncovered studies was conducted and an expert panel was consulted. Two reviewers screened the articles for eligibility according to the inclusion criteria. Methodological quality was assessed using the National Heart, Lung and Blood Institute’s (NHLBI’s) quality assessment tool. A total of 16 randomized controlled trials (RCTs) were finally included. All the authors extracted key data and descriptively analyzed the data. Thematic analysis was used to categorize the results into themes. Three major themes related to muscle growth were generated: (i) subjects of creatine supplementation—muscle growth is more effective in healthy young subjects than others; (ii) training of subjects—sufficient training is important in all populations; (iii) future direction and recommendation of creatine supplementation for muscle growth—injury prevention and utilization in medical practice. Overall, creatine is an efficient form of supplementation for muscle growth in the healthy young population with adequate training in a variety of dosage strategies and athletic activities. However, more well-designed, long-term RCTs with larger sample sizes are needed in older and muscular disease-related populations to definitively determine the effects of creatine supplementation on muscle growth in these other populations.

Evaluation of pre-workout and recovery formulations on body composition and performance after a 6-week high-intensity training program

“…The present study supports existing findings; LM increased significantly from baseline to post-testing with the SUP group gaining more LM (+1.1 kg) compared to the PL group (+0.88 kg) and CON group (+0.37 kg). The multi-ingredient formula consumed in the present study contained ingredients that have been known to support muscle protein synthesis (30) and tissue repair (20) addition of creatine monohydrate, a dietary supplement that has demonstrated improvements in LM especially when paired with resistance training (31). In a similar study evaluating nutrient timing around the same HIRT protocol implemented in women, consumption of nutrients (16 g CHO + 25 g PRO) before or after-exercise resulted in significantly greater increases in LM compared to no nutritional intake (PRE: +0.96 kg; Post: +0.64 kg; CON: +0.15 kg) (7).…”

“…The multi-ingredient formula consumed in the present study contained ingredients that have been known to support muscle protein synthesis ( 30 ) and tissue repair ( 20 ) [whey protein, casein protein, and β-hydroxy-β-methylbutyrate (HMB)], possibly supporting the greater, yet non-significant, increases in LM reported in the SUP group compared to CON. Furthermore, these increases in LM were observed without the addition of creatine monohydrate, a dietary supplement that has demonstrated improvements in LM especially when paired with resistance training ( 31 ). In a similar study evaluating nutrient timing around the same HIRT protocol implemented in women, consumption of nutrients (16 g CHO + 25 g PRO) before or after–exercise resulted in significantly greater increases in LM compared to no nutritional intake (PRE: +0.96 kg; Post: +0.64 kg; CON: +0.15 kg) ( 7 ).…”

The effect of physical activity on sleep disturbance in various populations: a scoping review of randomized clinical trials

“…The NHLBI tool does not have any set threshold for quality scores. Nonetheless, using general study quality assessment guidelines, the studies were characterized as having either low (≤50%), good (51–75%), or excellent (>75%) methodological quality [ 42 , 43 ].…”

Muscle Involvement in Amyotrophic Lateral Sclerosis: Understanding the Pathogenesis and Advancing Therapeutics

“…These studies reflect the continuous efforts to find compounds and therapeutic options that can successfully treat the muscular damage associated with ALS. While creatine supplementation has been found to improve muscular function [186], further research is needed to maximize its potential therapeutic advantages. Meanwhile, L-carnitine administration and adherence to specific energetic dietary regimens offers promising avenues for improving both muscle condition and overall disease progression in ALS patients [184].…”