Dietary creatine and cognitive function in U.S. adults aged 60 years and over.

OBJECTIVES: Recent clinical trials suggested a potential benefit of dietary creatine on cognitive function for aging individuals. However, the association between creatine consumption from food and cognitive function in the older adults remained undetermined at the populational level. The present study quantified the amount of creatine consumed through a regular diet among U.S. adults aged 60 years and over, and evaluated the link between dietary creatine and cognitive function using data from the 2001-2002 National Health and Nutrition Examination Survey (NHANES). METHODS: NHANES 2001-2002 round included a total of 1340 older adults (51.8% women; age 71.4 ± 7.8 years) who provided valid dietary information and cognitive testing measures. Dietary intake information was obtained from the NHANES Dietary Data component through a 24-h in-person dietary recall interview. Cognitive function was assessed using the WAIS III Digit Symbol Substitution Test (DSS) conducted during the household interview. RESULTS: A bivariate model revealed a significant positive correlation between DSS scores and creatine intake across the whole sample (τb = 0.043; P = 0.02). The partial models demonstrated a significant correlation between creatine consumption and DSS score when adjusted for sociodemographic variables (r = 0.062; P = 0.039), and nutritional variables (r = 0.055; P = 0.049). The participants who consumed more than 0.95 g of creatine per day (3rd and 4th quartiles of creatine intake) were found to have higher scores on the cognitive functioning test as compared to their peers with lower creatine intake (1st and 2nd quartiles) (P < 0.05). CONCLUSION: Our findings suggest that creatine from food might be protective against reduced cognitive performance in the older population. Further research is highly warranted to investigate the role of dietary creatine amount in cognitive function in the older adults.

Hydrotherapy with hydrogen-rich water compared with RICE protocol following acute ankle sprain in professional athletes: a randomized non-inferiority pilot trial.

We analysed the effects of an experimental novel protocol of intensive hydrotherapy with hydrogen-rich water (HRW) on injury recovery in athletic men who suffered an acute ankle sprain (AAS) and compared it with a RICE protocol (rest, ice, compression, elevation). Professional athletes (age 23.7 ± 4.0 years; weight 78.6 ± 5.7 kg, height 182.5 ± 4.3 cm; professional experience 5.9 ± 3.9 years) who incurred AAS during a sport-related activity were randomly assigned immediately after the injury to either hydrogen group (n = 9) or a conventional RICE treatment group (n = 9). Hydrogen group received six 30-min ankle baths with HRW throughout the first 24 h post-injury, with hydrotherapy administered every 4 hours during the intervention period. RICE group stood off the injured leg, with ice packs administered for 20 min every 3 hours, with the injured ankle compressed with an elastic bandage for 24 hours and elevated at all possible times above the level of the heart. HRW was equivalent to RICE protocol to reduce ankle swelling (2.1 ± 0.9% vs. 1.6 ± 0.8%; P = 0.26), range of motion (2.4 ± 1.3 cm vs. 2.7 ± 0.8 cm; P = 0.60), and single-leg balance with eyes opened (18.4 ± 8.2 sec vs. 10.7 ± 8.0 sec; P = 0.06) and closed (5.6 ± 8.4 sec vs. 3.9 ± 4.2 sec; P = 0.59). This non-inferiority pilot trial supports the use of HRW as an effective choice in AAS management. However, more studies are needed to corroborate these findings in other soft tissue injuries.

The effects of rapid weight loss on skeletal muscle in judo athletes.

OBJECTIVE: To observe the effect of rapid weight loss (RWL) methods over 3 days on muscle damage in judokas. METHODS: Eighteen judokas participated in this crossover study, meaning that judo athletes were subjected to exercise-only phase (4 days) and RWL phase (3 days). Subjects were tested for myoglobin, creatine kinase, aldolase, hemoglobin, and hematocrit values on seven consecutive days. These biomarkers served as indicators of acute muscle damage. RESULTS: During the exercise-only phase, no significant changes were observed. Myoglobin (Mb) (p < 0.001), creatine kinase (CK) (p < 0.001) and aldolase (ALD) (p < 0.001) significantly increased only during the RWL phase, as well as hemoglobin (Hb) (p < 0.001) and hematocrit (Hct) (p < 0.005) values. It was detected that peak values for muscle damage biomarkers were reached on the sixth day, while Hct and Hb values were the highest on the seventh day of the study. CONCLUSION: Our study showed significant muscle damage induced by RWL. The prevalence of RWL use by judokas is high but firm scientific evidence is lacking in the evaluation of the current practice of it. Therefore, further knowledge must be gained to evaluate the effectiveness of RWL on performance and its impact on judokas' wellbeing.

Correlation between biomarkers of creatine metabolism and serum indicators of peripheral muscle fatigue during exhaustive exercise in active men.

Exhaustive exercise induces various disturbances of homeostasis, with impaired bioenergetics often associated with strenuous muscular work. However, no study so far validated serum biomarkers of creatine metabolism vs. traditional markers of exhaustive exercise and fatigue. Here, we investigated how well changes in serum guanidinoacetic acid (GAA), creatine and creatinine correlate with responses in blood lactate, creatine kinase, interleukin-6 and cortisol in 11 young active men (age 23.2 ± 3.7 years; VO2max 49.5 ± 5.4 ml/kg/min) exposed to exhaustive exercise. All participants were subjected to running at individual running speed at anaerobic threshold until exhaustion, with venous blood drawn at baseline and during an exercise session at 5-min intervals. Running-to-exhaustion markedly affected serum GAA and creatine levels, with circulating GAA increased for 5.3 ± 8.5%(95% CI, -0.4 to 11.0), and serum creatine elevated by 33.9 ± 21.8% (95% CI, 19.3 to 48.6) compared to baseline levels (P ≤ 0.05). In addition, moderate-to-strong positive linear correlations were found between exhaustive exercise-induced changes in serum cortisol and GAA levels (r = 0.79; P = 0.03), and cortisol and creatine concentrations (r = 0.81; P = 0.03). This suggests a link between cortisol and heavy exercise-induced impaired bioenergetics, with future studies needed to evaluate a cause-and-effect interconnection between cortisol and GAA-creatine axis.

Short-term H2 inhalation improves running performance and torso strength in healthy adults.

In this randomized, double-blind, placebo-controlled, crossover pilot trial, we evaluated the effects of 7-day H2 inhalation on exercise performance outcomes and serum hormonal and inflammation profiles in a cohort of young men and women. All participants (age 22.9 ± 1.5 years; body mass index 23.4 ± 2.5 kg m-2; 10 women and 10 men) were allocated to receive either gaseous hydrogen (4%) or placebo (room air) by 20-min once-per-day inhalation for 7 days, with a wash-out period of 7 days to prevent the residual effects of interventions across study periods. The primary treatment outcome was the change in running time-to-exhaustion in the incremental maximal test from baseline to day 7. Additionally, assessment of other exercise performance endpoints and clinical chemistry biomarkers was performed at baseline and at 7 days after each intervention. The trial was registered at ClinicalTrials.gov (ID NCT03846141). Breathing 4% hydrogen for 20 min per day resulted in increased peak running velocity (by up to 4.2%) as compared to air inhalation (P = 0.05). Hydrogen inhalation resulted in a notable drop in serum insulin-like growth factor 1 (IGF-1) by 48.2 ng/mL at follow-up (95% confidence interval [CI]: from -186.7 to 89.3) (P < 0.05), while IGF-1 levels were elevated by 59.3 ng/mL after placebo intervention (95% CI; from -110.7 to 229.5) (P < 0.05). Inhalational hydrogen appears to show ergogenic properties in healthy men and women. Gaseous H2 should be further evaluated for its efficacy and safety in an athletic environment.

Serum creatine is not a reliable marker of muscular fitness in young adults.

PURPOSE: Elevated serum creatine and higher handgrip strength are individually associated with better health profiles yet the link between two variables remains unknown. In this cross-sectional study, we evaluated serum creatine levels in relation to handgrip strength in a cohort of 130 young healthy adults (61 women and 69 men; age 23.3 ± 2.6 years), while controlling for age, gender, fat-free mass and biomarkers of creatine metabolism as effect modifiers. MATERIALS AND METHODS: Serum creatine, creatinine and guanidinoacetic acid (GAA) levels were measured with liquid chromatography-tandem mass spectroscopy, while handgrip strength was assessed with a hydraulic hand dynamometer. RESULTS: Hierarchical multiple regression revealed that our model as a whole explained 79.9% of the variance in handgrip strength (p < 0.001). However, the evaluation of the contribution of each independent variable revealed that gender and free-fat mass make significant contributions (45.4 and 31.8%, respectively) to our model (p < 0.05), while neither age (0.9%) nor serum creatine (4.5%) or any other lab markers made significant contributions to the model (p > 0.05). CONCLUSIONS: Having higher blood creatine appears to be unrelated with better physical performance in young healthy adults. Serum creatine was not a reliable marker of muscular fitness in this population.

Effects of an integrative warm-up method on the range of motion, core stability, and quality of squat performance of young adults.

Introduction: This research aims to determine the effects of an integrative warm-up method on the range of motion in joints of the lower extremities, the strength of the stabilizer trunk muscles, and the quality of the basic movement patterns in older adolescents. Methods: The study sample consisted of 88 male students (age 20.1 ± 0.5). They were randomly divided into four groups: one control group (CG) (n = 17; 180.8 ± 7.9 cm; 82.3 ± 8.3 kg) and three experimental groups (EG): EG1 (n = 23; 180.9 ± 7.0 cm; 78.5 ± 9.5 kg), EG2 (n = 31; 182.2 cm ± 7.3 cm; 79.5 ± 11.5 kg), and EG3 (n = 17; 183.3 ± 4.9 cm; 77.5 ± 11.8 kg). The participants were subjected to a 6-week experimental treatment: EG1 once, EG2 twice, and EG3 three times a week. The experimental treatment consisted of four sub-phases representing the integrative warm-up Method: 1) Inhibition (self-myofascial release using a foam roller); 2) Lengthening (Static stretching in a maximum range of motion position); 3) Activation (Positional isometrics muscle activation of the trunk and gluteus); 4) Integration (Integrated all the previous phases into one complex movement pattern). Based on the covariance analysis (ANCOVA), statistically significant treatment effects were observed and positive changes were determined in all experimental groups. Results: The differences between groups were observed in the following variables: Overhead Squat Assessment (p = 0.000; ηp2=0.318), range of motion of left hip flexion (p = 0.000; ηp2=0.371), range of motion of right hip flexion (p = 0.000; ηp2=0.051) and range of motion of right hip extension (p = 0.051; ηp2=0.088), Double Leg Lowering Test (F = 2.411; p = 0.014; ηp2=0.014) and range of combined motion (plantar and dorsiflexion) of left ankle joint (p = 0.000; ηp2=0.299). There was no significant difference in the Plank Test (F = 1.007; p = 1.007; ηp2=0.035), range of combined motion (plantar and dorsiflexion) of right ankle joint (p = 0.088; ηp2=0.170) and range of motion of left hip extension (p = 0.158; ηp2=0.060). The participants of CG statistically significantly differed from EG1, EG2, and EG3 in the squat performance after the applied treatment. Discussion: The effect of the treatment was the occurrence of a transformational processes in almost all measured variables. It can be concluded that the integrative method is effective and applicable in practice for both young adults and recreational athletes.

The impact of six-week dihydrogen-pyrroloquinoline quinone supplementation on mitochondrial biomarkers, brain metabolism, and cognition in elderly individuals with mild cognitive impairment: a randomized controlled trial.

OBJECTIVES: To assess the impact of medium-term supplementation with dihydrogen and pyrroloquinoline quinone (PQQ) on mitochondrial biomarkers, brain metabolism, and cognition in elderly individuals diagnosed with mild cognitive impairment. DESIGN: A parallel-group, randomized, placebo-controlled, double-blind experimental design, maintaining a 1:1 allocation ratio between the experimental group (receiving the dihydrogen-producing minerals and PQQ) and the control group (receiving the placebo) throughout the trial. SETTING AND PARTICIPANTS: Thirty-four elderly individuals with mild cognitive impairment (mean age 71.9 ± 3.8 years; 28 females) voluntarily provided written consent to participate in this trial. Participants were assigned in a double-blind parallel-group design to receive either a dihydrogen-PQQ mixture (Alpha Hope®, CalerieLife, Irvine, CA) or placebo twice daily for a 6-week intervention period. METHODS: The primary endpoint was the change in serum brain-derived neurotrophic factor (BDNF) from baseline to the 6-week follow-up; secondary outcomes included cognitive function indices, specific metabolites in brain tissue, brain oxygenation, and the prevalence and severity of side effects. Interaction effects (time vs. intervention) were evaluated using two-way ANOVA with repeated measures and Friedman's 2-way ANOVA by ranks, for normally distributed data with homogeneous variances and non-homogeneous variances, respectively. RESULTS: Dihydrogen-PQQ resulted in a significant elevation in serum BDNF levels at the six-week follow-up (P = 0.01); conversely, no changes in BDNF levels were observed in the placebo group throughout the study duration (P = 0.27). A non-significant trend in the impact of interventions on BDNF levels was observed (treatment vs. time interaction, P = 0.14), suggesting a tendency for dihydrogen-PQQ to upregulate BDNF levels compared to the placebo. A significant interaction effect was observed for the Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) scores in the orientation domain (P = 0.03), indicating the superiority of dihydrogen-PQQ over placebo in enhancing this cognitive aspect. Cerebral oxygenation saturation exhibited a significant increase following the administration of the dihydrogen-PQQ mixture, from 48.4 ± 7.2% at baseline to 52.8 ± 6.6% at 6-week post-administration (P = 0.005). In addition, brain N-acetyl aspartate levels significantly increased at seven out of thirteen locations post-intervention in participants receiving the mixture (P ≤ 0.05). CONCLUSIONS: Despite the limited number of participants included in the study for interpreting clinical parameters, the dihydrogen-PQQ mixture blend shows promise as a potential dietary intervention for enhancing mental orientation and brain metabolism in individuals with age-related mild cognitive decline.

Eight-Week Creatine-Glucose Supplementation Alleviates Clinical Features of Long COVID.

Preliminary studies demonstrated beneficial effects of dietary creatine across different post-viral fatigue syndromes. Creatine is often co-administered with glucose to improve its potency yet whether glucose boost the efficacy of creatine in long COVID remains currently unknown. In this report, we investigate the effects of 8-wk creatine intake with and without glucose on patient-reported outcomes, exercise tolerance, and tissue creatine levels in patients with long COVID. Fifteen male and female long COVID adult patients (age 39.7±16.0 y; 9 women) with moderate fatigue and at least one of additional long COVID-related symptoms volunteered to participate in this randomized controlled parallel-group interventional trial. All patients were allocated in a double-blind parallel-group design (1 : 1 : 1) to receive creatine (8 g of creatine monohydrate per day), a mixture of creatine and glucose (8 g of creatine monohydrate and 3 g of glucose per day), or placebo (3 g of glucose per day) t.i.d. during an 8-wk intervention interval. Two-way ANOVA with repeated measures (treatment vs. time interaction) revealed significant differences in changes in total creatine levels between the groups, showing an interaction effect at two brain locations (right precentral white matter F=34.740, p=0.008; partial η2=0.72; left paracentral grey matter F=19.243, p=0.019; partial η2=0.88), with creatine and creatine-glucose outcompeted placebo to elevate creatine levels at these two locations. Several long COVID symptoms (including body aches, breathing problems, difficulties concentrating, headache, and general malaise) were significantly reduced in creatine-glucose group at 8-wk follow-up (p≤0.05); the effect sizes for reducing body aches, difficulties concentrating, and headache were 1.33, 0.80, and 1.12, respectively, suggesting a large effect of creatine-glucose mixture for these outcomes. Our preliminary findings suggest that supplying exogenous creatine with glucose could be recommended as an effective procedure in replenishing brain creatine pool and alleviating long COVID features in this prevalent condition.

Optimizing strength training protocols in young females: A comparative study of velocity-based and percentage-based training programs.

The purpose of this study was to compare the effects of velocity-based strength training (VBT) and percentage-based strength training (PBT) on absolute strength, explosive strength, speed, and agility, as well as markers of muscle damage after 6 weeks of exercise programs. The study included 30 young female individuals, divided into three groups of 10 participants: VBT, PBT, and control group. The main findings indicated that the VBT group and PBT group showed significant improvement in 1RM squat exercise (Δ% 27.87 and Δ% 8.98, respectively) and 1RM bench press (Δ% 14.47 and Δ% 8.65, respectively), but a greater enhancement was observed in the VBT group. In addition, VBT induced substantial changes in SJ (Δ% 14.32) and CMJ height (Δ% 7.69), while PBT had an improvement only in the SJ test (Δ% 6.72). The improvement noted in the VBT group could be attributed to its ability to tailor training intensity according to the speed of movement execution. This approach allows athletes to perform each repetition as fast as possible, thus maintaining an optimal intensity for explosive strength development. The capacity of VBT to adapt training intensity based on the speed of movement execution may be the key factor contributing to these results. Therefore, coaches and athletes should consider implementing VBT as a valuable tool to optimize strength and power development. In conclusion, VBT induced greater improvement in the 1RM squat, 1RM bench press, SJ, and CMJ compared to the group that performed the traditional strength training modality. Therefore, VBT is considered a more effective training tool regarding the development of absolute and explosive strength in young women.

Creatine consumption and liver disease manifestations in individuals aged 12 years and over.

Despite the overwhelming safety evidence concerning creatine intake in various settings, there is still incomplete information whether dietary creatine affects liver health at the population level. The main aim of this cross-sectional population-based study was to evaluate the association between creatine intake through regular diet and liver disease manifestations, including liver fibrosis and hepatic steatosis, among individuals aged 12 years and over, using open-source data from the 2017-2018 U.S. National Health and Nutrition Examination Survey (NHANES). A total of 9254 male and female participants of all ages were included in the 2017-2018 NHANES round. We extracted data from the total sample population for participants who provided dietary data for individual foods via dietary interviews and examination data from liver ultrasound transient elastography. The final study sample consisted of 5957 participants (mean age 44.7 ± 21.0 years; 50.1% women), and the mean dietary creatine intake across the study population was 0.88 ± 0.71 g/day. Liver fibrosis and cirrhosis were diagnosed in 1703 (28.7%) and 288 (4.8%) participants, respectively; hepatic steatosis was identified in 2595 (43.7%) individuals. Binary logistic regression with multivariable model adjusted for age, gender, family income to poverty ratio, body mass index, total energy intake, and alcohol consumption showed that consuming more creatine (≥2 g/day) did not significantly increase the risk of liver fibrosis (OR = 0.92, 95% CI 0.70-1.21, p = .57), cirrhosis (OR = 0.94, 95% CI 0.53-1.65, p = .82), or hepatic steatosis (OR = 0.77, 95% CI 0.59-1.02, p = .07), as compared to participants who ingested <1 g of creatine daily. Dietary exposure to creatine through a regular diet is not associated with an increase in disease manifestations in individuals 12 years and over; further research is warranted to address the effects of excessive creatine intake (≥5 g/day) through a regular diet on liver health at the population level.

Motivation Profile of Youth Greco-Roman Wrestlers; Differences According to Performance Quality.

Athletes have to possess high motivation levels to perform each training session and competition at the highest level. Thus, the motivation of the wrestler is essential to reach the highest performance quality. The research included 47 Greco-Roman wrestlers aged 17.71 ± 1.62 years. Variables included anthropometric indices, sports motivation assessed by the revised Sport Motivation Scale (SMS-II), and competitive success (medal winners and non-winners at the National Championship). The Cronbach's alpha coefficients checked the internal consistency of the SMS-II. Differences between performance quality were determined by Cohen's d effect sizes, and MANOVA for motivation and anthropometric variables/body build variables. In the total sample, wrestlers had high levels of intrinsic motivation (5.97 ± 0.90), integrated (5.99 ± 0.83), and identified (6.08 ± 0.82) regulation, while they had low amotivation (2.53 ± 0.98) and external regulation (3.26 ± 1.24). Successful wrestlers had significantly higher intrinsic motivation than less successful wrestlers (Cohen's d = 0.76, moderate effect size). Results evidenced that wrestlers have high self-determined motivation, which is vital for maximal performance and persisting in sports. Future research should investigate wrestlers from other age groups to ultimately determine the sport motivation profile of wrestlers and enable their optimal sports development.

Effects of Creatine Monohydrate on Endurance Performance in a Trained Population: A Systematic Review and Meta-analysis.

BACKGROUND: There is robust evidence that creatine monohydrate supplementation can enhance short-term high-intensity exercise in athletes. However, the effect of creatine monohydrate supplementation on aerobic performance and its role during aerobic activities is still controversial. OBJECTIVE: The purpose of this systematic review and meta-analysis was to evaluate the supplementation effects of creatine monohydrate on endurance performance in a trained population. METHODS: The search strategy in this systematic review and meta-analysis was designed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and PubMed/MEDLINE, Web of Science, and Scopus databases were explored from inception until 19 May, 2022. Only human experimental trials, controlled with a placebo group, evaluating the effects of creatine monohydrate supplementation on endurance performance in a trained population were analyzed in this systematic review and meta-analysis. The methodological quality of included studies was evaluated using the Physiotherapy Evidence Database (PEDro) scale. RESULTS: A total of 13 studies satisfied all the eligibility criteria and were included in this systematic review and meta-analysis. The results for the pooled meta-analysis showed a non-significant change in endurance performance after creatine monohydrate supplementation in a trained population (p = 0.47), with a trivial negative effect (pooled standardized mean difference = - 0.07 [95% confidence interval - 0.32 to 0.18]; I2 = 34.75%). Further, after excluding the studies not evenly distributed around the base of the funnel plot, the results were similar (pooled standardized mean difference = - 0.07 [95% confidence interval - 0.27 to 0.13]; I2 = 0%; p = 0.49). CONCLUSIONS: Creatine monohydrate supplementation was shown to be ineffective on endurance performance in a trained population. CLINICAL TRIAL REGISTRATION: The study protocol was registered in the Prospective Register of Systematic Review (PROSPERO) with the following registration number: CRD42022327368.

The Effects of Hydrogen-Rich Water on Blood Lipid Profiles in Clinical Populations: A Systematic Review and Meta-Analysis.

Over the last two decades, a plethora of disease models and human studies have confirmed the beneficial effects of molecular hydrogen (H2), a simple biotherapeutic gas. Recent small-scale studies evaluating the effects of hydrogen-rich water (HRW) on various metabolic conditions pointed to advantageous effects of HRW in regulating blood lipid profiles. However, to the best of the authors' knowledge, no systematic review and/or meta-analysis (SRMA) were published considering HRW consumption and lipid/lipoprotein status. Therefore, the aim of this SRMA was to assess the effects of HRW consumption on blood lipid panel in clinical populations. The search strategy was designed using PRISMA guidelines, and the databases PubMed/Medline, Web of Science, and Scopus were explored from inception until 4 October 2022. A total of seven studies satisfied all the eligibility criteria and were included in SRMA. The results for the pooled meta-analysis showed a significant reduction in total cholesterol, low-density lipoprotein, and triglycerides after HRW intake (p = 0.01), with small to moderate effects (pooled SMD = -0.23 (from -0.40 to 0.05); pooled SMD = -0.22 (from -0.39 to 0.04); pooled SMD = -0.38 (from -0.59 to 0.18), respectively). Our findings indicate that drinking HRW can significantly improve lipid status in the clinical populations. Additional studies are warranted to further validate this connection.

Effects of six-month creatine supplementation on patient- and clinician-reported outcomes, and tissue creatine levels in patients with post-COVID-19 fatigue syndrome.

Dietary creatine has been recently put forward as a possible intervention strategy to reduce post-COVID-19 fatigue syndrome yet no clinical study so far evaluated its efficacy and safety for this perplexing condition. In this parallel-group, randomized placebo-controlled double-blind trial, we analyzed the effects of 6-month creatine supplementation (4 g of creatine monohydrate per day) on various patient- and clinician-reported outcomes, and tissue creatine levels in 12 patients with post-COVID-19 fatigue syndrome. Creatine intake induced a significant increase in tissue creatine levels in vastus medialis muscle and right parietal white matter compared to the baseline values at both 3-month and 6-month follow-ups (p < .05). Two-way analysis of variance with repeated measures revealed a significant difference (treatment vs. time interaction) between interventions in tissue creatine levels (p < .05), with the creatine group was superior to placebo to augment creatine levels at vastus medialis muscle, left frontal white matter, and right parietal white matter. Creatine supplementation induced a significant reduction in general fatigue after 3 months of intake compared to baseline values (p = .04), and significantly improved scores for several post-COVID-19 fatigue syndrome-related symptoms (e.g., ageusia, breathing difficulties, body aches, headache, and difficulties concentrating) at 6-month follow-up (p < .05). Taking creatine for 6 months appears to improve tissue bioenergetics and attenuate clinical features of post-COVID-19 fatigue syndrome; additional studies are warranted to confirm our findings in various post-COVID-19 cohorts.