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

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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.publishedVersio

Effects of acute b-alanine supplemetation on countermovement jump performance after a 4x400 m fatigue protocol: a randomized, double-blind, placebo-controlled trial

This study aimed to examine the effect of acute beta-alanine (β-alanine) supplementation on jump performance after a strenuous fatigue protocol. Twelve healthy young men (age 21.4±0.5 years, body height 180.2±5.8 cm, body mass 76.6±9.2 kg) volunteered to participate in this randomized, double-blind, placebo-controlled trial. The experimental group ingested 3.2 g of β-alanine (separated into two 1.6 g dosages) mixed with 23 g of glucose, whereas the placebo group ingested two dosages containing 23 g of glucose. Following the supplementation intake, participants completed a jump protocol involving countermovement jump (CMJ) and four consecutive countermovement jumps (CMJ-4). Subsequently, a 4x400 m running fatigue protocol was carried out to produce fatigue. After the fatigue protocol, the same jumping tests were repeated, CMJ and CMJ-4, to evaluate the loss in jump height. The Mann-Whitney U test was used to analyze differences between the groups, whereas Wilcoxon signed-rank test was conducted to analyze differences within the groups with statistical significance set at p<.05. After β-alanine supplementation, no significant decrease in jump height was found in the experimental group in none of the tests after the fatigue protocol. Conversely, a significant decrease was noticed in the placebo group in CMJ but not in the CMJ-4 test. In conclusion, an acute β-alanine supplementation could attenuate jump height loss after the fatigue protocol. Therefore, athletes and coaches should consider acute β-alanine supplementation to attenuate sports performance decrease after high-intensity exercises in which muscle acidosis is highly increased

Searching for a better formulation to enhance muscle bioenergetics: A randomized controlled trial of creatine nitrate plus creatinine vs.

A novel creatine blend (creatine nitrate mixed with creatinine, CN‐CRN) has been anecdotally suggested to be superior to traditional creatine formulations for bioavailability and performance. However, does CN‐CRN supremely affects creatine levels in the blood and skeletal muscle of healthy humans remain currently unknown. This randomized, controlled, double‐blind, crossover trial evaluated the acute effects of single‐dose CN‐CRN on serum creatine levels, and 5‐days intervention with CN‐CRN on skeletal muscle creatine and safety biomarkers in healthy men. Ten healthy young men (23.6 ± 2.9 years) were allocated to receive either CN‐CRN (3 grams of creatine nitrate mixed with 3 grams of creatinine), pure creatine nitrate (3 grams, CN), or regular creatine monohydrate (3 grams, CRM) by oral administration. We found that CN‐CRN resulted in a more powerful rise in serum creatine levels comparing to either CN or CRM after a single‐dose intervention, as evaluated with the area under the concentration–time curve calculation (701.1 ± 62.1 (µmol/L) × min versus 622.7 ± 62.9 (µmol/L) × min versus 466.3 ± 47.9 (µmol/L) × min; p &lt; .001). The peak serum creatine levels at 60‐min sampling interval were significantly higher in CN‐CRN group (183.7 ± 15.5 µmol/L), as compared to CN group (163.8 ± 12.9 µmol/L) and CRM group (118.6 ± 12.9 µmol/L) (p &lt; .001). This was accompanied by a significantly superior increase in muscle creatine levels after CN‐CRN administration at 5‐days follow‐up, as compared to CN and CRM, respectively (9.6% versus 8.0% versus 2.1%; p = .01). While 2 out of 10 participants were found to be nonresponsive to CN intervention (20.0%) (e.g., no amplification in muscle creatine levels found at 5‐days follow‐up), and 3 participants out of 10 were nonresponsive in CRM trial (30%), no nonresponders were found after CN‐CRN administration, with individual upswing in total muscle creatine varied in this group from 2.0% (lowest increment) to 16.8% (highest increment). Supplemental CN‐CRN significantly decreased estimated glomerular filtration rate (eGFR) at 5‐days follow‐up, as compared to other interventions (p = .004), with the average reduction was 14.8 ± 7.7% (95% confidence interval; from 9.3 to 20.3). Nevertheless, no single participant experienced a clinically relevant reduction in eGFR (&lt; 60 ml/min/1.73 m2) throughout the course of the trial. Liver enzymes remained in reference ranges throughout the study, with no participant experienced high liver blood tests (e.g., AST &gt; 40 units per L or ALT &gt;56 units per L). Besides, no participant reported any major side effects during the trial, while the odors of CN‐CRN and CN formulations were considered somewhat unpleasant in 8 out of 10 participants (80.0%). Our results suggest that CN‐CRN is a preferred and relatively safe alternative to traditional creatine formulations for improved creatine bioavailability in the blood and skeletal muscle after single‐dose and 5‐days interventions

Searching for a better formulation to enhance muscle bioenergetics: A randomized controlled trial of creatine nitrate plus creatinine vs. creatine nitrate vs. creatine monohydrate in healthy men

A novel creatine blend (creatine nitrate mixed with creatinine, CN‐CRN) has been anecdotally suggested to be superior to traditional creatine formulations for bioavailability and performance. However, does CN‐CRN supremely affects creatine levels in the blood and skeletal muscle of healthy humans remain currently unknown. This randomized, controlled, double‐blind, crossover trial evaluated the acute effects of single‐dose CN‐CRN on serum creatine levels, and 5‐days intervention with CN‐CRN on skeletal muscle creatine and safety biomarkers in healthy men. Ten healthy young men (23.6 ± 2.9 years) were allocated to receive either CN‐CRN (3 grams of creatine nitrate mixed with 3 grams of creatinine), pure creatine nitrate (3 grams, CN), or regular creatine monohydrate (3 grams, CRM) by oral administration. We found that CN‐CRN resulted in a more powerful rise in serum creatine levels comparing to either CN or CRM after a single‐dose intervention, as evaluated with the area under the concentration–time curve calculation (701.1 ± 62.1 (µmol/L) × min versus 622.7 ± 62.9 (µmol/L) × min versus 466.3 ± 47.9 (µmol/L) × min; p &lt; .001). The peak serum creatine levels at 60‐min sampling interval were significantly higher in CN‐CRN group (183.7 ± 15.5 µmol/L), as compared to CN group (163.8 ± 12.9 µmol/L) and CRM group (118.6 ± 12.9 µmol/L) (p &lt; .001). This was accompanied by a significantly superior increase in muscle creatine levels after CN‐CRN administration at 5‐days follow‐up, as compared to CN and CRM, respectively (9.6% versus 8.0% versus 2.1%; p = .01). While 2 out of 10 participants were found to be nonresponsive to CN intervention (20.0%) (e.g., no amplification in muscle creatine levels found at 5‐days follow‐up), and 3 participants out of 10 were nonresponsive in CRM trial (30%), no nonresponders were found after CN‐CRN administration, with individual upswing in total muscle creatine varied in this group from 2.0% (lowest increment) to 16.8% (highest increment). Supplemental CN‐CRN significantly decreased estimated glomerular filtration rate (eGFR) at 5‐days follow‐up, as compared to other interventions (p = .004), with the average reduction was 14.8 ± 7.7% (95% confidence interval; from 9.3 to 20.3). Nevertheless, no single participant experienced a clinically relevant reduction in eGFR (&lt; 60 ml/min/1.73 m2) throughout the course of the trial. Liver enzymes remained in reference ranges throughout the study, with no participant experienced high liver blood tests (e.g., AST &gt; 40 units per L or ALT &gt;56 units per L). Besides, no participant reported any major side effects during the trial, while the odors of CN‐CRN and CN formulations were considered somewhat unpleasant in 8 out of 10 participants (80.0%). Our results suggest that CN‐CRN is a preferred and relatively safe alternative to traditional creatine formulations for improved creatine bioavailability in the blood and skeletal muscle after single‐dose and 5‐days interventions

A single session of exhaustive exercise markedly decreases circulating levels of guanidinoacetic acid in healthy men and women

We evaluated the effects of exercise on circulating concentrations of guanidinoacetic acid (GAA) and creatine in 23 healthy volunteers subjected to running to exhaustion and free-weight bench-press to volitional failure. Blood was taken before and following each exercise session. Running induced a significant decrease in serum GAA by 20.1% (PThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Differences in Motor Abilities of Younger School Children based on their Sex

The aim of this research is to determine whether there is any statistically signifi cant diff erence in motor abilities of boys and girls of younger school age. The sample includes 76 examinees with 37 males and 39 females. All are 5th and 6 th graders of primary school. The evaluation of motor abilitied is based on 5 tests. Multivariant analysis of variance is applied for determination of diff erences within the whole system of motor tests, whereas univariant analysis of variance is used for determining diff erences in each motor test. According to the fi ndings, statistically signifi cant diff erences in motor abilities between boys and girls at the studied age can be noticed in the test 20 m running from fl ying start, which is in favour of boys and in the test sit and reach, in favour of girls, while the diff erences in other tests are not statistically signifi cant. Considering the evaluation of motor abilities, boys have statistically much better results in the speed of alternative movements and explosive strenth, whereas girls have achieved much better results in the test for fl exibility. It has also been concluded that 5th and 6th graders have statistically better results in the space of coordination and explosive strenght, whereas girls are much better in the fi eld of fl exibility and suppleness