The effects of TeaCrine® and caffeine on endurance and cognitive performance during a simulated match in high-level soccer players

The dose-dependent effect of caffeine supplementation on performance, reaction time and postural stability in CrossFit - a randomized placebo-controlled crossover trial

BACKGROUND

Caffeine (CAF) ingestion improves performance in a broad range of exercise tasks. Nevertheless, the CAF-induced, dose-dependent effect on discipline-specific performance and cognitive functions in CrossFit/High-Intensity Functional Training (HIFT) has not been sufficiently investigated. The aim of this study was to evaluate the effect of acute supplementation of three different doses of CAF and placebo (PLA) on specific performance, reaction time (RTime), postural stability (PStab), heart rate (HR) and perceived exertion (RPE).

METHODS

In a randomized double-blind placebo-controlled crossover design, acute pre-exercise supplementation with CAF (3, 6, or 9 mg/kg body mass (BM)) and PLA in 26 moderately trained CrossFit practitioners was examined. The study protocol involved five separate testing sessions using the Fight Gone Bad test (FGB) as the exercise performance evaluation and biochemical analyses, HR and RPE monitoring, as well as the assessment of RTime and PStab, with regard to CYP1A2 (rs762551) and ADORA2A (rs5751876) single nucleotide polymorphism (SNP).

RESULTS

Supplementation of 6 mgCAF/kgBM induced clinically noticeable improvements in FGBTotal results, RTime and pre-exercise motor time. Nevertheless, there were no significant differences between any CAF doses and PLA in FGBTotal, HRmax, HRmean, RPE, pre/post-exercise RTime, PStab variables or pyruvate concentrations. Lactate concentration was higher (p < 0.05) before and after exercise in all CAF doses than in PLA. There was no effect of CYP1A2 or ADORA2A SNPs on performance.

CONCLUSIONS

The dose-dependent effect of CAF supplementation appears to be limited to statistically nonsignificant but clinically considered changes on specific performance, RTime, PStab, RPE or HR. However, regarding practical CAF-induced performance implications in CrossFit/HIFT, 6 mgCAF/kgBM may be supposed as the most rational supplementation strategy.

Comparative analysis of antioxidant activities and chemical compositions in the extracts of different edible parts from Camellia tetracocca Zhang (C. tetracocca) with two distinct color characteristics

The Camellia tetracocca Zhang is a rare and ancient plant, exclusively found in the vicinity of Puan County, Guizhou Province, China. According to leaf color, two distinct variations have been identified: purple C. tetracocca Zhang (PCTZ) and green C. tetracocca (GCTZ). This research was conducted to investigate the antioxidant activities and chemical compositions of different edible parts of PCTZ and GCTZ. Antioxidant activity was evaluated using DPPH, ABTS, HSA, and T-AOC assays, while the content of compounds was determined by HPLC. The findings demonstrated that the antioxidant capacity of PCTZ leaves is significantly superior to that of GCTZ leaves. Notably, theacrine, a rare compound, contains up to 2.075% in PCTZ leaves, indicating potential as a novel natural antidepressant and antioxidant. In conclusion, PCTZ is a distinctive tea beverage and a valuable genetic material for tea tree breeding due to its high theacrine and low caffeine characteristics.

Effect of single or combined caffeine and L-Theanine supplementation on shooting and cognitive performance in elite curling athletes: a double-blind, placebo-controlled study

PURPOSE

Previous studies have investigated the effect of single or combined caffeine (CAF) and L-theanine (THE) intake on attention performance. However, its effect on shooting performance and cognitive performance in a sport is unknown. The aim of this study was to investigate the hypothesis "Does single or combined CAF and THE supplementation have an effect on shooting and cognitive performance in elite curling athletes?." It is predicted that over the next decade, studies based on nutritional ergogenic supplements in the developing sport of curling will continue to increase, leading to a significant increase in studies examining the effects of CAF and THE supplementation, alone or in combination, on throwing and cognitive performance in elite curling athletes.

METHODS

In this double-blind, randomized controlled crossover study, twenty-two elite national curling athletes (age 20.20 ± 1.61 and sports age 6.20 ± 0.51 years, height 174.10 ± 7.21 cm, BMI 21.80 ± 3.47 kg/m2) were randomly assigned to CAF (6 mg/kg single dose CAF), THE (6 mg/kg single dose THE), CAF*THE (6 mg/kg CAF and 6 mg/kg THE combined) and PLA (400 mg maltodextrin) groups at each of four sessions. 60 minutes after taking the supplement, the athletes were first given the Stroop test and then asked to shoot.

RESULTS

Our main findings have shown that the performance of athletes in guard (F=3.452, P < .001, ηp2 = .842), draw (F=1.647, P < .001, ηp2 = .485), and take-out (F=3.121, P < .001, ηp2 = .743) shot styles significantly improved when comparing the combined intake of CAF and THE to the PLA. Regarding cognitive performance evaluation through the Stroop test, during the NR task (F=4.743, P = .001, ηp2 = .653), the combined intake of CAF and THE significantly improved reaction times compared to the intake of single CAF, THE, or PLA. The best reaction times during the CR and ICR (respectively; F=2.742, P = .004, ηp2 = .328; F = 1.632, P < .001, ηp2 = .625) tasks were achieved with the combined CAF and THE intake, showing a significant improvement compared to PLA. During the NER (F=2.961, P < .001, ηp2 = .741), task, the combined intake of CAF and THE significantly improved error rates compared to the intake of CAF, THE, or PLA single. The best accuracy rates during the CER and ICER (respectively; F=4.127, P < .001, ηp2 = .396; F=3.899, P < .001, ηp2 = .710) tasks were achieved with the combined CAF and THE intake, leading to a significant reduction in error rates compared to PLA. Based on these findings, it has been demonstrated in this study that the best shooting scores and cognitive performance were achieved, particularly with the combined intake of CAF and THE.

CONCLUSIONS

Based on these findings, it has been demonstrated in this study that the best shooting scores and cognitive performance were achieved, particularly with the combined intake of CAF and THE. The combined use of these supplements has been found to be more effective on shooting and cognitive performance than their single use.

Proteomics analysis to investigate the potential mechanism of theacrine against UV-induced skin photodamage

AIM

This study aimed to explore the underlying mechanism of theacrine treatment of UV-induced skin photodamage.

MATERIALS AND METHODS

Tandem Mass Tag (TMT) relative quantitative proteomics analysis was used to characterize the proteins and pathways associated with the ability of theacrine to combat photodamage in mouse skin by modeling UV irradiation of the backs of ICR mice.

RESULTS

Apoptosis-related proteins and signaling pathways play a key role in the ability of theacrine to protect against skin photodamage, according to proteomic and bioinformatics analysis; molecular docking and Western blotting further revealed that theacrine was associated with apoptosis-related proteins (p53, Bcl-2, Bax, caspase-3, and cleaved-caspase-3) with strong binding affinity, which can significantly reduce skin cell apoptosis induced by UV exposure.

CONCLUSION

The findings revealed that theacrine can reduce UVB-induced epidermal damage by controlling the apoptosis signaling pathway, implying that theacrine could be a useful anti-UVB damage agent.

Methylliberine Ingestion Improves Various Indices of Affect but Not Cognitive Function in Healthy Men and Women

This study assessed the acute effects of oral methylliberine (DynamineTM) supplementation on cognitive function and indices of well-being. This was a double-blind, randomized, within-subject crossover trial. In total, 25 healthy men and women (33.5 ± 10.7 yr, 172.7 ± 8.6 cm, 73.3 ± 11.0 kg) underwent pretesting before ingesting methylliberine (100 mg) or a placebo (PLA) for 3 days. On the fourth day, the participants were tested before their fourth dose (baseline) and every hour post-ingestion for 3 h. After a one-week washout period, the participants repeated testing with the alternate investigational product. The testing battery consisted of vitals, Stroop test, Trail Making Test-B, and visual analog scales that assessed various indices of well-being. Mixed factorial ANOVAs with repeated measures were used to assess all variables. There were significant (p ≤ 0.050) interactions in terms of concentration, motivation, and mood. Methylliberine improved concentration at 1 and 3 h, motivation at 3 h, and mood at 1, 2, and 3 h (p ≤ 0.050). Methylliberine improved energy, sustained energy, and mood in all participants to a greater extent than PLA at 1 h and 3 h relative to baseline (p ≤ 0.050). PLA improved motivation at 1 and 2 h and mood at 2 h (p ≤ 0.050). Methylliberine improved concentration, well-being, and the ability to tolerate stress to a greater extent than PLA at 3 h relative to baseline (p ≤ 0.050). Women observed elevations in sustained energy at 1 and 3 h (p ≤ 0.050) with methylliberine vs. PLA. Methylliberine had a negligible influence on cognitive function and vitals (p > 0.050), and no adverse events were reported. Methylliberine significantly improved subjective feelings of energy, concentration, motivation, and mood, but not cognitive function. PLA improved motivation and mood at hours 1 and 2, while methylliberine sustained these benefits for longer. Methylliberine also improved concentration, well-being, and the ability to tolerate stress to a greater degree than PLA, while having no detrimental effects on vital signs. Methylliberine also seemed to have a positive impact on sustained energy in women.

A Combination of Caffeine, TeaCrine, and Dynamine Improves the Neurophysiological and Performance Measures of Electronic (E)-Gamers

INTRODUCTION

Video games require precise motor skills, quick reaction times, and cognitive engagement. The tremendous growth of the electronic (e)-gaming industry has increased the demands for cognitive supplements (e.g., nootropics) to help e-athletes gain a competitive edge. The primary aim of this study was to evaluate the effects of combined caffeine + TeaCrine + Dynamine measures of neurophysiological and first-person shooter game performance in e-gamers.

METHODS

Using a randomized double-blinded, crossover design, we assessed the effects of an acute, single-dose treatment of caffeine (200 mg) vs. caffeine (200 mg) + TeaCrine (10 mg) + Dynamine (50 mg) (CTD) vs. Ppacebo (maltodextrin). Each participant was tested under all three conditions one week apart. Baseline and post-dose measures were tested one hour apart. Participants [n = 49 male (24.4 ±, 4.5 yr)] were amateur e-gamers who play a first-person video game for at least 10 hours/week. Gaming performance was assessed through a series of first-person shooter training games through AIMLAB (State Space Labs, Inc., New York, USA). These included Reflex Shot (RS) standard, speed, and precision. The neurophysiological activity was captured while participants played three games through a single-channel EEG.

RESULTS

In the standard game, the caffeine and the CTD conditions shot significantly more targets relative to the placebo, and both caffeine and the CTD condition had significantly greater targets post-dose compared to pre-dose. However, both the placebo and caffeine conditions had significantly slower reaction times post-dose compared to pre-dose. In the speed game, both the caffeine and placebo conditions shot a significantly greater number of targets, while the placebo and caffeine conditions had significantly more shots post-dose compared to pre-dose. Only the CTD condition had a significant increase in total kills post-dose compared to pre-dose. In the precision game, only the CTD condition significantly improved the number of kills per second post-dose, while only the caffeine condition had more shots post-dose. EEG data collected concomitantly with game playing showed that the CTD condition resulted in significantly lower alpha power compared to the placebo condition. The CTD group also showed increased theta activity post-dose during game playing compared to both the placebo caffeine conditions.

CONCLUSION

CTD appears to improve overall shooting gaming performance and neurophysiological measures of cognitive activity compared to caffeine and placebo. Collectively, these findings suggest that CTD assists with speed-accuracy tradeoffs where caffeine-only can lead to erratic play; thus, CTD may be particularly beneficial for shooting precision. The EEG data support this notion since the CTD exhibited lower alpha power suggesting increased cognitive flexibility and arousal and higher theta power suggesting greater cognitive control and decision-making under pressure.

Effects of caffeine, methylliberine, and theacrine on vigilance, marksmanship, and hemodynamic responses in tactical personnel: a double-blind, randomized, placebo-controlled trial

Background

Tactical athletes require fast reaction times (RT) along with high levels of vigilance and marksmanship performance. Caffeine has been shown to improve these measures but also results in increased blood pressure and jitteriness. Research on other purine alkaloids, such as methylliberine and theacrine, has suggested they do not increase blood pressure or jitteriness to the same extent, but their impact on tactical performance is unknown.

Methods

A between-subjects, randomized, placebo-controlled design was used to test the effects of placebo (PLA), 300 mg caffeine (CAF), and a combination of 150 mg caffeine, 100 mg methylliberine, and 50 mg theacrine (CMT) on RT and marksmanship along with hemodynamic and arousal measures following a sustained vigilance task in tactical personnel (n = 48). Following consumption of the supplement, participants underwent a 150-min protocol consisting of two rounds. Each round began with leisurely reading followed by a 30-min vigilance task before beginning two trials of movement and marksmanship tasks. Hemodynamics and felt arousal were assessed throughout the protocol. Composite Z-scores were calculated for overall performance measures at each timepoint, and mixed-effects models were used to assess differences in RT, accuracy, and composite Z-scores along with hemodynamics and felt arousal. An α-level of 0.05 was used to determine statistical significance, and Cohen’s d was used to quantify effect sizes.

Results

A Group-by-Time interaction for vigilance RT (P = 0.038) indicated improvements for both CAF and CMT from round 1 to round 2 (P < 0.01) while PLA did not change (P = 0.27). No Group main effects or Group-by-Time interactions were found for movement or marksmanship performance (P > 0.20). Group main effects for systolic (SBP; P = 0.001) and diastolic blood pressure (DBP; P = 0.028) indicated higher SBP in CAF (P = 0.003, d= 0.84) and CMT (P = 0.007, d= 0.79) compared to PLA but only higher DBP in CAF (P = 0.025, d= 0.74). No Group-by-Time interaction or Group main effect was found for felt arousal (P > 0.16).

Conclusions

These findings suggest similar benefits on RT during a vigilance task between CAF, containing 300 mg caffeine, and CMT above PLA, though CAF resulted in slightly less favorable hemodynamic changes. This study is the first to provide data showing similar efficacy of combined caffeine, methylliberine, and theacrine compared to double the caffeine dose consumed alone on vigilance RT but without a significant rise in DBP above PLA in tactical personnel.

Effects of Theacrine as a Pre-Workout Supplement

The search to increase physical performance is inherent to physical activity practitioners, and nutrition features are among the alternatives to seeking such an increase. The literature from the area has shown that different substances can promote beneficial effects over physical performance. One substance that has come into the spotlight is theacrine, an alkaloid similar to caffeine, which aims to increase physical performance. However, the studies on this supplement are scarce. Therefore, this study is a randomized, controlled trial that aimed to verify the effects of theacrine supplementation over physical performance in young male athletes, by applying a battery of physical tests. Twenty-two male amateur flag-football athletes were recruited. Subjects were divided into two groups and assessed at two moments, which were 72 h apart. The first assessment served as a basal measurement. In the second, the subjects ingested the supplement or a placebo 60 min before the following tests: sextuple jump, agility T test, 30 m sprint, 40 s run test (Matsudo test), and 12 min run test (Cooper test). There was no difference between the groups in any of the tests. Therefore, the findings of this study do not support the use of theacrine to increase physical performance.

Sex Differences Across the Life Course: A Focus On Unique Nutritional and Health Considerations among Women

In the United States, women, while having a longer life expectancy than men, experience a differential risk for chronic diseases and have unique nutritional needs based on physiological and hormonal changes across the life span. However, much of what is known about health is based on research conducted in men. Additional complexity in assessing nutritional needs within gender include the variations in genetics, body compositions, hormonal milieus, underlying chronic diseases, and medication usage, with this list expanding as we consider these variables across the life course. It is clear women experience nutrient shortfalls during key periods of their lives, which may differentially impact their health. Consequently, as we move into the era of precision nutrition, understanding these sex- and gender-based differences may help optimize recommendations and interventions chosen to support health and weight management. Recently, a scientific conference was convened with content experts to explore these topics from a life-course perspective at biological, physiological, and behavioral levels. This publication summarizes the presentations and discussions from the workshop and provides an overview of important nutrition and related lifestyle considerations across the life course. The landscape of addressing female-specific nutritional needs continues to grow; now more than ever, it is essential to increase our understanding of the physiological differences between men and women, and determine how these physiological considerations may aid in optimizing nutritional strategies to support certain personal goals related to health, quality of life, sleep, and exercise performance among women.

Theacrine does not enhance physical performance or training status over 8 weeks

Fatigue is a condition that may affect physical performance during training sessions. Consequently, this will impact training performance and will also affect the performance of the individual in the long term. Caffeine is extensively used to counteract fatigue; however, it contains several side effects. Theacrine might be used as an alternative to caffeine, providing the same benefits without the side effects. The current study aimed to investigate the effects of 8 weeks of supplementation with theacrine on physical performance and training status of young amateur athletes. Twenty-two subjects were divided into two groups – Theacrine Group (T) and Placebo Group (P) – and evaluated before and after the intervention period. Evaluations included physical tests and hormonal values of insulin like growth factor (IGF)-I and IGF binding protein (IGFBP)-3, used as markers of training status. Results demonstrated that theacrine was not capable of promoting benefits regarding the physical performance of the subjects. It also had no effects on serum secretion of IGF-I and its binding protein, IGFBP-3. Therefore, the findings of this study do not support the use of theacrine to increase physical performance.

Active Women Across the Lifespan: Nutritional Ingredients to Support Health and Wellness

Women are the largest consumers of dietary supplements. Dietary supplements can play a role in health and performance, particularly for women. Growing evidence and innovations support the unique physiological and nutrient timing needs for women. Despite the need for more nutrition and exercise-specific research in women, initial data and known physiological differences between sexes related to the brain, respiration, bone, and muscle support new product development and evidence-based education for active women regarding the use of dietary supplements. In this narrative review, we discuss hormonal and metabolic considerations with the potential to impact nutritional recommendations for active women. We propose four potential areas of opportunity for ingredients to help support the health and well-being of active women, including: (1) body composition, (2) energy/fatigue, (3) mental health, and (4) physical health.

A Combination of Caffeine, TeaCrine® (Theacrine), and Dynamine® (Methylliberine) Increases Cognitive Performance and Reaction Time Without Interfering With Mood in Adult Male Egamers

Background

Involvement in video game activities and competitive video gaming (esports) is a rapidly growing field. Moreover, there is a marked interest in identifying nutritional supplements to safely improve egamer performance.

Methodology

We conducted a repeated-measure, randomized crossover study to compare the effects of caffeine (125 mg), caffeine (125 mg) + Dynamine® (75 mg) + TeaCrine® (50 mg) (CDT), and matched placebo across three testing sessions (one week apart) among 50 young male egamers. We tested the effect of each product on multiple measures of cognition, self-reported mood (anxiety, alertness, and headache), and biomarkers of arousal (cortisol and salivary alpha-amylase). We also measured electroencephalogram power during the cognitive tasks. Finally, we tested whether individual differences in xenobiotic metabolism would affect the study outcome measures by genotyping each participant for cytochrome P450 1A2*1F (CYP1A2*1F) allele status.

Results

Compared to pre-dose, CDT improved performance on the Flanker Test of Inhibitory Control and improved reaction time on the Psychomotor Vigilance Task post-dose. Compared to the placebo, caffeine increased self-reported anxiety whereas the CDT combination increased self-reported alertness. Compared to the CDT combination, caffeine increased self-reported headaches. Physiological measures suggested that increases in delta EEG power and cortisol production are associated with the effects observed in the CDT condition to optimize certain aspects of egamer performance. CYP1A2*1F allele status did not moderate outcome variables between conditions in this study.

Conclusions

CDT is a safe and effective product for improving cognitive performance among egamers without increasing self-reported anxiety or headaches. EEG changes demonstrate that CDT increased attention to internal processing (i.e., increased cortical delta power) and potentially increased cognitive control (i.e., increased cortical theta frequency), while the increases in cortisol suggest increased energy mobilization. Future work should aim to clarify the physiological underpinnings of CDT-induced changes in performance and examine the effects of CDT under naturalistic egamer conditions.

Does Acute Caffeine Supplementation Improve Physical Performance in Female Team-Sport Athletes? Evidence from a Systematic Review and Meta-Analysis

Introduction: Recent original research and meta-analyses suggest that acute caffeine supplementation improves exercise performance in team-sport athletes (TSA). Nonetheless, most of the studies testing the effects of caffeine on TSA included samples of male athletes, and there is no meta-analysis of the performance-enhancing effects of caffeine on female TSA. The aim of the present study was to synthesize the existing literature regarding the effect of caffeine supplementation on physical performance in adult female TSA. Methods: A search was performed in Pubmed/Medline, SPORTDiscus and Scopus. The search was performed from the inception of indexing until 1 September 2021. Crossover randomized controlled trials (RCT) assessing the effects of oral caffeine intake on several aspects of performance in female TSA were selected. The methodological quality and risk of bias were assessed for individual studies using the Physiotherapy Evidence Database scale (PEDro) and the RoB 2 tool. A random-effects meta-analysis of standardized mean differences (SMD) was performed for several performance variables. Results: The search retrieved 18 articles that fulfilled the inclusion/exclusion criteria. Overall, most of the studies were of excellent quality with a low risk of bias. The meta-analysis results showed that caffeine increased performance in specific team-sport skills (SMD: 0.384, 95% confidence interval (CI): 0.077–0.691), countermovement jump (SMD: 0.208, CI: 0.079–0.337), total body impacts (SMD: 0.488; 95% CI: 0.050, 0.927) and handgrip strength (SMD: 0.395, CI: 0.126–0.665). No effects were found on the ratings of perceived exertion, squat jumps, agility, repeated sprint ability or agility tests performed after fatigue. Conclusions: The results of the meta-analysis revealed that acute caffeine intake was effective in increasing some aspects of team-sports performance in women athletes. Hence, caffeine could be considered as a supplementation strategy for female athletes competing in team sports.

Effects of Caffeine Supplementation on Physical Performance of Soccer Players: Systematic Review and Meta-Analysis

CONTEXT

Caffeine is 1 of the most popular supplements consumed by athletes, and the evidence for improving soccer performance remains limited.

OBJECTIVE

To investigate and update the effects (benefits and harms) of caffeine to improve performance on soccer players.

DATA SOURCES

Electronic search in Medline (via PubMed), CENTRAL, Embase, SPORTDiscus, and LILACS, from inception to March 28, 2020.

STUDY SELECTION

Randomized clinical trials (RCTs) assessing the effects of caffeine on the performance of soccer players.

STUDY DESIGN

Systematic review with meta-analysis.

LEVEL OF EVIDENCE

Level 1.

DATA EXTRACTION

Data extraction was conducted independently by 2 authors using a piloted form. We assessed methodological quality (Cochrane risk-of-bias [RoB] table) and the certainty of the evidence (GRADE [Grading of Recommendations Assessment, Development and Evaluation] approach).

RESULTS

Sixteen RCTs were included. Overall methodological quality was classified as unclear to low risk of bias. When assessing aerobic endurance, meta-analyses did not demonstrate the differences between caffeine and placebo (mean difference [MD], 44.9 m; 95% confidence interval [CI], -77.7 to 167.6). Similarly, no difference was observed during time to fatigue test (MD, 169.8 seconds; 95% CI, -71.8 to 411.6). Considering anaerobic power, meta-analyses also did not find differences for vertical jump (MD, 1.01 cm; 95% CI, -0.68 to 2.69) and repeated sprint tests (MD, -0.02 seconds; 95% CI, -0.09 to 0.04), as well as reaction time agility test (MD, 0.02 seconds; 95% CI, -0.01 to 0.04) and rating of perceived exertion (MD, 0.16 points; 95% CI, -0.55 to 0.87). Regarding safety, a few minor adverse events were reported. Based on the GRADE approach, the certainty of this evidence was classified as very low to low.

CONCLUSION

We found no significant improvement in soccer-related performance with caffeine compared with placebo or no intervention. However, caffeine appears to be safe.

Topical Review: The Top Five Peripheral Vision Tools in Sport

SIGNIFICANCE

This study summarizes the empirical evidence on the use of peripheral vision for the most-researched peripheral vision tools in sports.

The objective of this review was to explain if and how the tools can be used to investigate peripheral vision usage and how empirical findings with these vision tools might be transferred to sports situations. The data sources used in this study were Scopus, ScienceDirect, and PubMed. We additionally searched the manufacturers' Web pages and used Google Scholar to find full texts that were not available elsewhere. Studies were included if they were published in a peer-reviewed journal, were written in English language, and were conducted in a sports context. From the 10 searched tools, we included the 5 tools with most published studies. In our topical search, we identified 93 studies for the five most-used peripheral vision tools. Surprisingly, none of these studies used eye-tracking methods to control for the use of peripheral vision. Best "passive" control is achieved by tools using (foveal) secondary tasks (Dynavision D2 and Vienna Test System). Best transfer to sports tasks is expected for tools demanding action responses (FitLight, Dynavision D2). Tools are likely to train peripheral monitoring (NeuroTracker), peripheral reaction time (Dynavision D2, Vienna Test System), or peripheral preview (FitLight), whereas one tool did not show any link to peripheral vision processes (Nike SPARQ Vapor Strobe).

Mechanisms of Physical Fatigue and its Applications in Nutritional Interventions

Physical fatigue during exercise can be defined as an impairment of physical performance. Multiple factors have been found contributing to physical fatigue, including neurotransmitter-mediated defense action, insufficient energy supply, and induction of oxidative stress. These mechanistic findings provide a sound theoretical rationale for nutritional intervention since most of these factors can be modulated by nutrient supplementation. In this review, we summarize the current evidence regarding the functional role of nutrients supplementation in managing physical performance and propose the issues that need to be addressed for better utilization of nutritional supplementation approach to improve physical performance.

Caffeine and Cognitive Functions in Sports: A Systematic Review and Meta-Analysis

Cognitive functions are essential in any form of exercise. Recently, interest has mounted in addressing the relationship between caffeine intake and cognitive performance during sports practice. This review examines this relationship through a structured search of the databases Medline/PubMed and Web of Science for relevant articles published in English from August 1999 to March 2020. The study followed PRISMA guidelines. Inclusion criteria were defined according to the PICOS model. The identified records reported on randomized cross-over studies in which caffeine intake (as drinks, capsules, energy bars, or gum) was compared to an identical placebo situation. There were no filters on participants’ training level, gender, or age. For the systematic review, 13 studies examining the impacts of caffeine on objective measures of cognitive performance or self-reported cognitive performance were selected. Five of these studies were also subjected to meta-analysis. After pooling data in the meta-analysis, the significant impacts of caffeine only emerged on attention, accuracy, and speed. The results of the 13 studies, nevertheless, suggest that the intake of a low/moderate dose of caffeine before and/or during exercise can improve self-reported energy, mood, and cognitive functions, such as attention; it may also improve simple reaction time, choice reaction time, memory, or fatigue, however, this may depend on the research protocols.

Potential Herb-Drug Interactions in the Management of Age-Related Cognitive Dysfunction

Late-life mild cognitive impairment and dementia represent a significant burden on healthcare systems and a unique challenge to medicine due to the currently limited treatment options. Plant phytochemicals have been considered in alternative, or complementary, prevention and treatment strategies. Herbals are consumed as such, or as food supplements, whose consumption has recently increased. However, these products are not exempt from adverse effects and pharmacological interactions, presenting a special risk in aged, polymedicated individuals. Understanding pharmacokinetic and pharmacodynamic interactions is warranted to avoid undesirable adverse drug reactions, which may result in unwanted side-effects or therapeutic failure. The present study reviews the potential interactions between selected bioactive compounds (170) used by seniors for cognitive enhancement and representative drugs of 10 pharmacotherapeutic classes commonly prescribed to the middle-aged adults, often multimorbid and polymedicated, to anticipate and prevent risks arising from their co-administration. A literature review was conducted to identify mutual targets affected (inhibition/induction/substrate), the frequency of which was taken as a measure of potential interaction. Although a limited number of drugs were studied, from this work, interaction with other drugs affecting the same targets may be anticipated and prevented, constituting a valuable tool for healthcare professionals in clinical practice.

Theacrine From Camellia kucha and Its Health Beneficial Effects

Theacrine, i.e., 1,3,7,9-tetramethyluric acid, is one of the major purine alkaloids found in leaf of a wild tea plant species Camellia kucha Hung T. Chang. Theacrine has been attracted great attentions academically owing to its diverse health benefits. Present review examines the advances in the research on the health beneficial effects of theacrine, including antioxidant effect, anti-inflammatory effect, locomotor activation and reducing fatigue effects, improving cognitive effect, hypnotic effect, ameliorating lipid metabolism and inhibiting breast cancer cell metastasis effect. The inconsistent results in this research field and further expectations were also discussed.

Padrões de consumo de bebidas energéticas e suplementos alimentares à base de cafeína por frequentadores de academias

Objetivo: Avaliar o nível de conhecimento, hábitos, e prevalência de consumo de energéticos e suplementos à base de cafeína por praticantes de exercícios físicos em academias. Métodos: Foi empregado um questionário autoaplicável de 27 perguntas no Google® Forms, divulgado em mídias sociais entre setembro e outubro de 2018. Resultados: Participaram 200 frequentadores de academias, 71% adultos jovens, 52% tendo mais de 2 anos de prática e frequência regular de 5 - 6 vezes por semana. A maioria da amostra era mulher (58,5%), praticante de musculação (61,6%) de MG (62,5%). O consumo sem orientação profissional foi de 81,6% nos energéticos e 53,9% para suplementos à base de cafeína. 73,3% dos consumidores de energéticos tinham objetivos relacionados com atividades sociais, preferindo a marca RedBul® (40,4%). Entre os consumidores de suplementos de cafeína houve preferência por termogênicos (32,7%) e cafeína pura (29,9%), com objetivo principal a melhora de performance (28,7%), apresentando respostas ergolíticas de taquicardia e palpitações como registrado nos energéticos. Não houve registro de efeitos adversos em 19,2% dos consumidores de cafeína e 40,8% de energéticos. As dosagens de consumo dos produtos estavam dentro da faixa de segurança (< 6 mg/kg). Conclusão: O consumo de ambos produtos foi feito sem orientação profissional, porém, com dosagens dentro da faixa de segurança. O consumo de bebidas energéticas esteve voltado para atividades sociais e melhora da performance esportiva. Foram registrados efeitos ergolíticos.

A Theacrine-Based Supplement Increases Cellular NAD+ Levels and Affects Biomarkers Related to Sirtuin Activity in C2C12 Muscle Cells In Vitro

There is evidence in rodents to suggest that theacrine-based supplements modulate tissue sirtuin activity as well as other biological processes associated with aging. Herein, we examined if a theacrine-based supplement (termed NAD3) altered sirtuin activity in vitro while also affecting markers of mitochondrial biogenesis. The murine C2C12 myoblast cell line was used for experimentation. Following 7 days of differentiation, myotubes were treated with 0.45 mg/mL of NAD3 (containing ~2 mM theacrine) for 3 and 24 h (n = 6 treatment wells per time point). Relative to control (CTL)-treated cells, NAD3 treatments increased (p < 0.05) Sirt1 mRNA levels at 3 h, as well as global sirtuin activity at 3 and 24 h. Follow-up experiments comparing 24 h NAD3 or CTL treatments indicated that NAD3 increased nicotinamide phosphoribosyltransferase (NAMPT) and SIRT1 protein levels (p < 0.05). Cellular nicotinamide adenine dinucleotide (NAD⁺) levels were also elevated nearly two-fold after 24 h of NAD3 versus CTL treatments (p < 0.001). Markers of mitochondrial biogenesis were minimally affected. Although these data are limited to select biomarkers in vitro, these preliminary findings suggest that a theacrine-based supplement can modulate select biomarkers related to NAD⁺ biogenesis and sirtuin activity. However, these changes did not drive increases in mitochondrial biogenesis. While promising, these data are limited to a rodent cell line and human muscle biopsy studies are needed to validate and elucidate the significance of these findings.

Theacrine and strictinin, two major ingredients for the anti-influenza activity of Yunnan Kucha tea

ETHNOPHARMACOLOGICAL RELEVANCE

Kucha tea plant (Camellia assamica var. kucha Chang et Wang) is regarded as a mutant variety of wild Pu'er tea plant found in few mountain areas of Yunnan, China. Its fresh young leaves and shoots are picked by the indigenous aborigines in these local areas to prepare an herbal tea for the treatment of common cold empirically.

MATERIALS AND METHODS

Two extra compounds of relative abundance were detected in Kucha tea in comparison with Pu'er tea, and their chemical structures were identified as chlorogenic acid and theacrine. These two compounds as well as two major compounds, strictinin and caffeine, in Kucha tea were evaluated for their cytotoxicity and inhibitory effects on human influenza virus A/Puerto Rico/8/34 by analyzing viral protein expression and progeny production.

RESULTS

No or low cytotoxicity was detected for the four Kucha compounds when their concentrations were below 100 μM. Expression of viral NS1 protein was significantly inhibited by chlorogenic acid, theacrine or strictinin, but not caffeine at a concentration of 100 μM. The relative inhibitory potency was detected as chlorogenic acid < theacrine < strictinin, and both theacrine and strictinin displayed significant inhibition at a concentration of 50 μM. According to a plaque assay, viral progeny production was significantly reduced by theacrine or strictinin, but not by chlorogenic acid or caffeine under the same concentration of 100 μM.

CONCLUSION

It is suggested that theacrine and strictinin are two major ingredients responsible for the anti-influenza activity of Yunnan Kucha tea traditionally used for the treatment of common cold.

Effects of Various Doses of Caffeine Ingestion on Intermittent Exercise Performance and Cognition

To date, no study has examined the effects of caffeine on prolonged intermittent exercise performance that imitates certain team-sports, and the suitable concentration of caffeine for improved intermittent exercise performance remains elusive. The purpose of the present cross-over, double-blind preliminary study was to investigate effects of low, moderate, and high doses of caffeine ingestion on intermittent exercise performance and cognition. Ten males performed a familiarization session and four experimental trials. Participants ingested capsules of placebo or caffeine (3, 6, or 9 mg/kg) at 1 h before exercise, rested quietly, and then performed cycling for 2 × 30 min. The cycling protocol consisted of maximal power pedaling for 5 s (mass × 0.075 kp) every minute, separated by unloaded pedaling for 25 s and rest for 30 s. At pre-ingestion of capsules, 1 h post-ingestion, and post-exercise, participants completed the Stroop task. The mean power-output (MPO), peak power-output (PPO), and response time (RT) in the Stroop task were measured. Only 3 mg/kg of caffeine had positive effects on the mean PPO and MPO; 3 mg/kg caffeine decreased RTs significantly in the incongruent and congruent conditions. These results indicate that the ingestion of low-dose caffeine had greater positive effects on the participants' physical strength during prolonged intermittent exercise and cognition than moderate- or high-dose caffeine.

Theacrine, a purine alkaloid from kucha, protects against Parkinson's disease through SIRT3 activation

BACKGROUND

Oxidative damage of dopaminergic neurons is the fundamental causes of Parkinson's disease (PD) that has no standard cure at present. Theacrine, a purine alkaloid from Chinese tea Kucha, has been speculated to benefit the neurodegeneration in PD, through similar actions to its chemical analogue caffeine, albeit excluding side effects. Theacrine has nowadays gained a lot of interest for its multiple benefits, while the investigations are weak and insufficient.

HYPOTHESIS/PURPOSE

It is well-known that tea has a wide range of functions, especially in the prevention and treatment of neurodegenerative diseases. Theacrine is an active monomer compound in Camellia assamica var. kucha Hung T. Chang & H.S.Wang (Kucha), which appears to be effective and safe in PD therapy. The aim of this study is to examine its actions in diverse PD models and explore the mechanisms.

STUDY DESIGN

For determination of theacrine's effects, we employed diverse oxidative damage-associated PD models, including 6-OHDA-treated rats, MPTP-treated mice/zebrafish and MPP⁺-treated SH-SY5Y cells, and using caffeine, selegiline and depranyl as positve control. For investigation and verification of the mechanisms, we utilized approaches testing mitochondrial function-related parameters and enzyme activity as well as applied gene knockdown and overexpression.

METHODS

We employed behavioral tests including spontaneous activity, pole, swimming, rotarod and gait, immunohistochemistry, HPLC, flow cytometry, immunohistochemistry, Western blot, gene knockdown by siRNA and overexpression by plasmid in this study.

RESULTS

Theacrine is demonstrated to retrieve the loss of dopaminergic neurons and the damages of behavioral performance in multiple animal models of PD (6-OHDA-treated rats and in MPTP-treated mice and zebrafish). The followed data of MPP⁺-treated SH-SY5Y cells indicate that theacrine relieves apoptosis resulted from oxidative damage and mitochondrial dysfunction. Further investigations illustrate that theacrine activates SIRT3 directly. It is of advantage to prevent apoptosis through SIRT3-mediated SOD2 deacetylation that reduces ROS accumulation and restores mitochondrial function. This concept is elaborated by 3TYP that inhibits SIRT3 enzyme activity and knockdown/overexpression of SIRT3 gene, demonstrating a crucial role of SIRT3 in theacrine-benefited dopaminergic neurons.

CONCLUSION

Theacrine prevents apoptosis of dopaminergic neurons through directly activating SIRT3 which deacetylating SOD2 and restoring mitochondrial functions.

Safety of Short-Term Supplementation with Methylliberine (Dynamine®) Alone and in Combination with TeaCrine® in Young Adults

Methylliberine (Dynamine^®; DYM) and theacrine (Teacrine^®; TCR) are purine alkaloids purported to have similar neuro-energetic effects as caffeine. There are no published human safety data on DYM, and research on TCR is limited. The purpose of this study was to examine the effect of four weeks of DYM supplementation with and without TCR on cardiovascular function and blood biomarkers. One-hundred twenty-five men and women (mean age 23.0 yrs, height 169.7 cm, body mass 72.1 kg; n = 25/group) were randomly assigned to one of five groups: low-dose DYM (100 mg), high-dose DYM (150 mg), low-dose DYM with TCR (100 mg + 50 mg), high-dose DYM with TCR (150 mg + 25 mg) , and placebo. Regardless of group and sex, significant main effects for time were noted for heart rate, systolic blood pressure, and QTc (p < 0.001), high-density lipoproteins (p = 0.002), mean corpuscular hemoglobin (p = 0.018), basophils (p = 0.006), absolute eosinophils (p = 0.010), creatinine (p = 0.004), estimated glomerular filtration rate (p = 0.037), chloride (p = 0.030), carbon dioxide (p = 0.023), bilirubin (p = 0.027), and alanine aminotransferase (p = 0.043), among others. While small changes were found in some cardiovascular and blood biomarkers, no clinically significant changes occurred. This suggests that DYM alone or in combination with TCR consumed at the dosages used in this study does not appear to negatively affect markers of health over four weeks of continuous use.

The effects of a caffeine-like supplement, TeaCrine®, on muscular strength, endurance and power performance in resistance-trained men

Background

TeaCrine® is the synthetic version to naturally occurring theacrine (1, 3, 7, 9-tetramethyluric acid) found in the leaves of Camellia kucha tea plants. A few studies have examined the effects of TeaCrine® on cognitive perception, but no research exists examining its effects on resistance exercise performance. The purpose of this study was to determine the efficacy of TeaCrine®, a caffeine-like compound, on maximal muscular strength, endurance, and power performance in resistance-trained men.

Methods

Twelve resistance-trained men participated in a randomized, double-blind, cross-over designed study. Each participant performed one-repetition maximum (1RM) bench press, 1RM squat, bench press repetitions to failure (RTF) at 70% 1RM, squat RTF at 70% 1RM, and 2-km rowing time trial 90 min after consumption of: (1) Caffeine 300 mg (CAFF300); (2) TeaCrine® 300 mg (TEA300); (3) TeaCrine® + Caffeine (COMBO; 150 mg/150 mg); (4) Placebo 300 mg (PLA). Power and velocity were measured using a TENDO Power Analyzer. Visual analogue scales for energy, focus, motivation to exercise, and fatigue were administered at baseline and 90 min post-treatment ingestion (pre-workout). Rating of perceived exertion was assessed after bench press RTF and squat RTF.

Results

There were no differences between groups for 1RM, RTF, and power in the bench press and squat exercises. Only CAFF300 resulted in significant increases in perceived energy and motivation to exercise vs. TEA300 and PLA (Energy: + 9.8%, 95% confidence interval [3.3–16.4%], p < 0.01; + 15.3%, 95% CI [2.2–28.5%], p < 0.02; Motivation to exercise: + 8.9%, 95% CI [0.2–17.6%], p = 0.04, + 14.8%, 95% CI [4.7–24.8%], p < 0.01, respectively) and increased focus (+ 9.6%, 95% CI [2.1–17.1%], p = 0.01) vs. TEA300, but there were no significant differences between CAFF300 and COMBO (Energy + 3.9% [− 6.9–14.7%], Focus + 2.5% [− 6.3–11.3%], Motivation to exercise + 0.5% [− 11.6–12.6%]; p > 0.05).

Conclusion

Neither TEA300, CAFF300, COMBO, or PLA (when consumed 90 min pre-exercise) improved muscular strength, power, or endurance performance in resistance-trained men. Only CAFF300 improved measures of focus, energy, and motivation to exercise.

Cognitive function assessment during 2 mA transcranial direct current stimulation in DLPFC in healthy volunteers

Although cognitive function has been reported to change following the anodal transcranial direct current stimulation (tDCS) but still variable results have been reported in healthy subject and there is paucity of data on the cognitive effects of online tDCS. Therefore, we aimed to assess the online effect of tDCS over the left dorsolateral prefrontal cortex (DLPFC) on cognitive function and obtain safety data in healthy adults. We recruited 36 healthy (20 male) participants for this double-blind, sham-controlled parallel design. We used Stop Signal Task (SST) Go Trial and Pattern Recognition Memory (PRM) tests to evaluate cognitive function during 2 mA (20 min) anodal or sham tDCS stimulation over the left DLPFC. In active conditions, left dorsolateral prefrontal cortex was selected for electrode placement with reference over right supraorbital cortex. All related tasks were done during the online tDCS section in both groups (active/sham). There were statistically significant differences in cognitive function according to the PRM test (P = 0.003), SST (P = 0.021), and SST correct response time on Go Trials (P = 0.02) during active stimulation compared to the sham group. Our results reveal that cognitive performance is affected by a single dose of active online tDCS over DLPFC area compared to sham stimulation. In our study, tDCS is well-tolerated and safe that further supports the safety of tDCS in local healthy population.