Creatine supplementation does not enhance submaximal aerobic training adaptations in healthy young men and women

Creatine supplementation and VO2max: a systematic review and meta-analysis

Although creatine supplementation is well-known to increase exercise performance in acute high-intensity exercises, its role in aerobic performance based on VO₂max is more controversial. Thus, we performed a systematic review and meta-analysis on the effects of creatine supplementation on VO₂max. PubMed, Cochrane, Embase, and ScienceDirect were searched for randomized controlled trials (RCTs) reporting VO₂max in creatine supplementation and placebo groups before and after supplementation. We computed a random-effects meta-analysis on VO₂max at baseline, within groups following supplementation, on changes on VO₂max between groups, and after supplementation between groups. Sensitivity analyses and meta-regression were conducted. We included 19 RCTs for a total of 424 individuals (mean age 30 years old, 82% men). VO₂max did not differ at baseline between groups (creatine and placebo). Participants in both groups were engaged in exercise interventions in most studies (80%). Using changes in VO₂max, VO₂max increased in both groups but increased less after creatine supplementation than placebo (effect size [ES] = -0.32, 95%CI = -0.51 to -0.12, p = 0.002). Comparisons after creatine supplementation confirmed a lower VO₂max in the creatine group compared to the placebo group (ES= -0.20, 95%CI = -0.39 to -0.001, p = 0.049). Meta-analysis after exclusion from meta-funnel resulted in similar outcomes in a subgroup of young and healthy participants. Meta-regressions on characteristics of supplementation, physical training, or sociodemographic were not statistically significant. Creatine supplementation has a negative effect on VO₂max, regardless of the characteristics of training, supplementation, or population characteristics.Supplemental data for this article is available online at https://doi.org/10.1080/10408398.2021.2008864 .

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.

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

Abstract Introduction: Recent studies have pointing creatine supplementation as a promising therapeutic alterna- tive in several diseases, especially myopathies and neurodegenerative disorder. Objective: elucidate the role of creatine supplementation on deleterious effect caused by limb immobilization in humans and rats. Methods: Analyzed articles were searched by three online databases, PubMed, SportDicus e Scielo. After a review and analysis, the studies were included in this review articles on effect of creatine supplementation on skeletal muscle in humans and rat, before, during and after a period of limb immobilization. Results: Studies analyzed demonstrated positive points in use of creatine supplementation as a therapeutic tool to mitigating the deleterious effects of limb immobilization, in humans and rat. Conclusion: The dataset of this literature review allows us to conclude that creatine supplementation may reduce muscle loss and/or assist in the recovery of muscle atrophy caused by immobilization and disuse in rats and humans. Also, we note that further research with better methodological rigor is needed to clarify the mechanisms by which creatine support the recovery of muscle atrophy. Moreover, these effects are positive and promising in the field of muscle rehabilitation, especially after member’s immobilization.

Effects of creatine monohydrate supplementation on simulated soccer performance

PURPOSE

To determine the effects of acute short-term creatine (Cr) supplementation on physical performance during a 90-min soccer-specific performance test.

METHODS

A double-blind, placebo-controlled experimental design was adopted during which 16 male amateur soccer players were required to consume 20 g/d Cr for 7 d or a placebo. A Ball-Sport Endurance and Speed Test (BEAST) comprising measures of aerobic (circuit time), speed (12- and 20-m sprint), and explosive-power (vertical jump) abilities performed over 90 min was performed presupplementation and postsupplementation.

RESULTS

Performance measures during the BEAST deteriorated during the second half relative to the first for both Cr (1.2-2.3%) and placebo (1.0-2.2%) groups, indicating a fatigue effect associated with the BEAST. However, no significant differences existed between groups, suggesting that Cr had no performance-enhancing effect or ability to offset fatigue. When effect sizes were considered, some measures (12-m sprint, -0.53 ± 0.69; 20-m sprint, -0.39 ± 0.59) showed a negative tendency, indicating chances of harm were greater than chances of benefit.

CONCLUSIONS

Acute short-term Cr supplementation has no beneficial effect on physical measures obtained during a 90-min soccer-simulation test, thus bringing into question its potential as an effective ergogenic aid for soccer players.

The effects of four weeks of creatine supplementation and high-intensity interval training on cardiorespiratory fitness: a randomized controlled trial

Background

High-intensity interval training has been shown to be a time-efficient way to induce physiological adaptations similar to those of traditional endurance training. Creatine supplementation may enhance high-intensity interval training, leading to even greater physiological adaptations. The purpose of this study was to determine the effects of high-intensity interval training (HIIT) and creatine supplementation on cardiorespiratory fitness and endurance performance (maximal oxygen consumption (VO_2PEAK), time-to-exhaustion (VO_2PEAKTTE), ventilatory threshold (VT), and total work done (TWD)) in college-aged men.

Methods

Forty-three recreationally active men completed a graded exercise test to determine VO_2PEAK, VO_2PEAKTTE, and VT. In addition, participants completed a time to exhaustion (TTE) ride at 110% of the maximum workload reached during the graded exercise test to determine TWD (TTE (sec) × W = J). Following testing, participants were randomly assigned to one of three groups: creatine (creatine citrate) (Cr; n = 16), placebo (PL; n = 17), or control (n = 10) groups. The Cr and PL groups completed four weeks of HIIT prior to post-testing.

Results

Significant improvements in VO_2PEAK and VO_2PEAKTTE occurred in both training groups. Only the Cr group significantly improved VT (16% vs. 10% improvement in PL). No changes occurred in TWD in any group.

Conclusion

In conclusion, HIIT is an effective and time-efficient way to improve maximal endurance performance. The addition of Cr improved VT, but did not increase TWD. Therefore, 10 g of Cr per day for five days per week for four weeks does not seem to further augment maximal oxygen consumption, greater than HIIT alone; however, Cr supplementation may improve submaximal exercise performance.