Oral creatine supplementation attenuates muscle loss caused by limb immobilization: a systematic review

Nutritional Strategies in the Rehabilitation of Musculoskeletal Injuries in Athletes: A Systematic Integrative Review

It is estimated that three to five million sports injuries occur worldwide each year. The highest incidence is reported during competition periods with mainly affectation of the musculoskeletal tissue. For appropriate nutritional management and correct use of nutritional supplements, it is important to individualize based on clinical effects and know the adaptive response during the rehabilitation phase after a sports injury in athletes. Therefore, the aim of this PRISMA in Exercise, Rehabilitation, Sport Medicine and Sports Science PERSiST-based systematic integrative review was to perform an update on nutritional strategies during the rehabilitation phase of musculoskeletal injuries in elite athletes. After searching the following databases: PubMed/Medline, Scopus, PEDro, and Google Scholar, a total of 18 studies met the inclusion criteria (Price Index: 66.6%). The risk of bias assessment for randomized controlled trials was performed using the RoB 2.0 tool while review articles were evaluated using the AMSTAR 2.0 items. Based on the main findings of the selected studies, nutritional strategies that benefit the rehabilitation process in injured athletes include balanced energy intake, and a high-protein and carbohydrate-rich diet. Supportive supervision should be provided to avoid low energy availability. The potential of supplementation with collagen, creatine monohydrate, omega-3 (fish oils), and vitamin D requires further research although the effects are quite promising. It is worth noting the lack of clinical research in injured athletes and the higher number of reviews in the last 10 years. After analyzing the current quantitative and non-quantitative evidence, we encourage researchers to conduct further clinical research studies evaluating doses of the discussed nutrients during the rehabilitation process to confirm findings, but also follow international guidelines at the time to review scientific literature.

Creatine supplementation effect on recovery following exercise-induced muscle damage: A systematic review and meta-analysis of randomized controlled trials

Exercise-induced muscle damage (EIMD) causes increased soreness, impaired function of muscles, and reductions in muscle force. Accumulating evidence suggests the beneficial effects of creatine on EIMD. Nevertheless, outcomes differ substantially across various articles. The main aim of this meta-analysis was to evaluate the effect of creatine on recovery following EIMD. Medline, Embase, Cochrane Library, Scopus, and Google Scholar were systematically searched up to March 2021. The Cochrane Collaboration tool for examining the risk of bias was applied for assessing the quality of studies. Weighted mean difference (WMD), 95% confidence interval (CI), and random-effects model, were applied for estimating the overall effect. Between studies, heterogeneity was examined using the chi-squared and I² statistics. Nine studies met the inclusion criteria. Pooled data showed that creatine significantly reduced creatine kinase (CK) concentration overall (WMD = -30.94; 95% CI: -53.19, -8.69; p = .006) and at three follow-up times (48, 72, and 96 hr) in comparison with placebo. In contrast, effects were not significant in lactate dehydrogenase (LDH) concentration overall (WMD = -5.99; 95% CI: -14.49, 2.50; p = .167), but creatine supplementation leaded to a significant reduction in LDH concentrations in trials with 48 hr measurement of LDH. The current data indicate that creatine consumption is better than rest after diverse forms of damaging and exhaustive exercise or passive recovery. The benefits relate to a decrease in muscle damage indices and improved muscle function because of muscle power loss after exercise. PRACTICAL APPLICATIONS: Creatine supplementation would be effective in reducing the immediate muscle damage that happens <24, 24, 48, 72, and 96 hr post-exercise. In the current meta-analysis, the positive effects of creatine could cause a decrease in CK concentration overall. But, due to high heterogeneity and the medium risk of bias for articles, we suggest that these results are taken into account and the facts are interpreted with caution by the readers.

Regulative Mechanism of Guanidinoacetic Acid on Skeletal Muscle Development and Its Application Prospects in Animal Husbandry: A Review

Guanidinoacetic acid is the direct precursor of creatine and its phosphorylated derivative phosphocreatine in the body. It is a safe nutritional supplement that can be used to promote muscle growth and development. Improving the growth performance of livestock and poultry and meat quality is the eternal goal of the animal husbandry, and it is also the common demand of today's society and consumers. A large number of experimental studies have shown that guanidinoacetic acid could improve the growth performance of animals, promote muscle development and improve the health of animals. However, the mechanism of how it affects muscle development needs to be further elucidated. This article discusses the physical and chemical properties of guanidinoacetic acid and its synthesis pathway, explores its mechanism of how it promotes muscle development and growth, and also classifies and summarizes the impact of its application in animal husbandry, providing a scientific basis for this application. In addition, this article also proposes future directions for the development of this substance.

The Application of Creatine Supplementation in Medical Rehabilitation

Numerous health conditions affecting the musculoskeletal, cardiopulmonary, and nervous systems can result in physical dysfunction, impaired performance, muscle weakness, and disuse-induced atrophy. Due to its well-documented anabolic potential, creatine monohydrate has been investigated as a supplemental agent to mitigate the loss of muscle mass and function in a variety of acute and chronic conditions. A review of the literature was conducted to assess the current state of knowledge regarding the effects of creatine supplementation on rehabilitation from immobilization and injury, neurodegenerative diseases, cardiopulmonary disease, and other muscular disorders. Several of the findings are encouraging, showcasing creatine's potential efficacy as a supplemental agent via preservation of muscle mass, strength, and physical function; however, the results are not consistent. For multiple diseases, only a few creatine studies with small sample sizes have been published, making it difficult to draw definitive conclusions. Rationale for discordant findings is further complicated by differences in disease pathologies, intervention protocols, creatine dosing and duration, and patient population. While creatine supplementation demonstrates promise as a therapeutic aid, more research is needed to fill gaps in knowledge within medical rehabilitation.