Performance-enhancing Effects Research Articles

Acute effects of combined isometric and plyometric conditioning activities on sports performance and tendon stiffness in female volleyball players.

This study aimed to compare the effects of bilateral and unilateral conditioning activities (CA; combined isometric and plyometric) on countermovement jump performance, modified t-agility test, Achilles tendon stiffness and skin surface temperature. Thirteen female semi-professional volleyball players performed two CAs in random order: 1) bilateral isometric half back squats followed by bilateral drop jumps (BI-CA); and 2) unilateral isometric half back squats followed by unilateral drop jumps (UNI-CA). To assess the effects of CAs, countermovement jump, modified t-agility test, Achilles tendon stiffness and skin surface temperature measurements were performed 5 min before and 6 min after the CA. Both CAs significantly increased thigh skin surface temperature from pre- to post-CA (BI-CA, p < 0.001; effect size [ES] = 1.41 and UNI-CA, p = 0.001; ES = 1.39) but none of them influenced modified t-agility test time (interaction: p = 0.338, main effect of time: p = 0.121 and condition: p = 0.819). The countermovement jump height and modified reactive strength index significantly increased from pre-to post-CA during the BI-CA condition (p = 0.003, ES = 0.45, and p = 0.008, ES = 0.48) but not for UNI-CA (p = 0.061, ES = 0.18 and p = 0.065, ES = 0.26). No significant impact has been found for countermovement depth (interaction: p = 0.054, main effect of time: 0.097, and condition: p = 0.41) as well as for contraction time (interaction: p = 0.536, main effect of time: p = 0.224, and condition: p = 0.807). Moreover, stronger and weaker limb CMJ relative peak force significantly decreased from pre-to post-CA (p = 0.014, ES = −0.31, and p = 0.027, ES = −0.26; respectively) during UNI-CA condition but not for BI-CA (p = 0.096, ES = 0.23, and p = 1.41, ES = 0.18). The stronger and weaker limb Achilles tendon stiffness significantly increased from pre-to post-CA during the UNI-CA condition (p = 0.013, ES = 0.60 and p < 0.001, ES = 0.79; respectively) but not for BI-CA (p = 0.66; ES = 0.15 and p = 0.265; ES = 0.42). Furthermore, the post-CA stronger limb Achilles tendon stiffness during the UNI-CA was significantly higher than that noted during the BI-CA (p = 0.006, ES = 0.7). The present study showed that combined isometric and plyometric bilateral CA effectively improved the countermovement jump but did not enhance the t-agility test performance. These findings indicate that exercise combinations could effectively produce a post-activation performance enhancement effect but should replicate the following explosive task as much as possible.

Effect of Mindfulness Sport Performance Enhancement (MSPE) to Reduce competitive state anxiety on Karate Athletes

Competitive state anxiety influences cognitive, emotional, and athlete behaviour while they have to perform perfectly in a competition. This study was conducted to analyze the effect of Mindfulness Sports Performance Enhancement (MSPE) training on competitive state anxiety of karate athletes in Surabaya. The research method used is quantitative with an experimental design. The sample in this study was 28 Karate athletes from Dojo Shiroite and INKAI in Surabaya. Those samples were selected using quota sampling. The intervention provided was an MSPE intervention adapted from Mindfulness Sports Performance Enhancement (MSPE). The data collection method was carried out using a competitive state anxiety scale adapted from The Revised Competitive State Anxiety Inventory – 2 with 17 items. The data were analyzed by paired t-test with SPSS 26. The result showed a significant decrease in the average competitive state anxiety by 9.25 points. This condition is supported by the decrease in cognitive anxiety and somatic anxiety dimension by 7.76 and 3.86 points. The decrease was also followed by an increase in the self-confidence dimension by 8.21 points. The findings in this study show the importance of continuous mental mindfulness training to improve athlete performance by overcoming competitive state anxiety. This research can also be a reference for practitioners and researchers. MSPE training can be developed as an effort to improve or solve problems related to an athlete's condition.

Acute effects of ballistic and non-ballistic conditioning activities on the punching impact of amateur boxers

Objectives This study investigated the postactivation performance enhancement (PAPE) effects of medicine ball throwing (MBT) and bench pressing (BP) on punching impact at different recovery times. Methods Fourteen amateur boxers performed three lead-hand (lead-hand) and rear-hand straight punches (rear-hand) at 3, 6, 9, 12, and 15 min after MBT or BP exercise. Peak force, time to the peak force, and rate of force development (RFD) of each punch was measured by a force plate. Results There was no significant condition × time interaction effect for any variables (lead-hand: F = 0.744–0.913, p = 0.448–0.542; rear-hand: F = 0.240–1.355, p = 0.245–0.944). No significant main effect for condition for any variables (lead-hand: F = 0.103–0.219, p = 0.644–0.751; rear-hand: F = 0.070–0.459, p = 0.504–0.793). The time effect was significant on peak force ( F = 4.411, p = 0.005) and RFD ( F = 5.002, p = 0.002) of lead-hand, time to the peak force ( F = 5.791, p = 0.001) and RFD ( F = 5.514, p = 0.001) of rear-hand. Peak force and RFD of the lead-hand, as well as time to the peak force and RFD of the rear-hand enhanced significantly at 6–15 min ( p = 0.001–0.042), compared to the baseline. Conclusions MBT and BP may equally enhance punching impact for amateur boxers; moreover, there was no difference in recovery time between conditioning activities.

Customer Engagement in International Markets

Relationship marketing managers around the world actively try to stimulate customer engagement because of its performance-enhancing effects. Research insights into how to engage customers, such that they voluntarily contribute their resources to support companies’ marketing efforts, almost exclusively pertain to individual, domestic markets. However, the prerequisites of customer engagement strategies naturally differ across country-specific market environments. Therefore, the authors develop a conceptual, comprehensive battery of cultural, institutional, societal, and economic country-level contingency factors (CISE indicators) as well as between-country psychic distances on those indicators. A set of 11 high-level research propositions aims to enhance marketing researchers’ and managers’ understanding of the contingencies of international customer engagement strategy effectiveness and customer engagement's performance ramifications. The analysis reflects the richness and complexity of potential contingency effects across the four CISE categories and encourages empirical research on their separate and joint effects.

Briefly Noted

On February 14, 2022, an ad hoc division of the Court of Arbitration for Sport (CAS) issued its decision in the case involving Russian figure skater Kamila Valieva. Valieva was suspended from participation in the 2022 Winter Olympic Games after the detection of a banned substance in her blood. The suspension was lifted by a decision issued by the Russian Anti-Doping Agency (RUSADA) Disciplinary Anti-Doping Committee on February 9, 2022, allowing her to continue in the Olympics. The applicants (the International Olympic Committee, the World Anti-Doping Agency, and the International Skating Union) challenged the lifting of the suspension. The CAS denied the applicants' challenge and allowed Valieva to participate in the Games. The CAS held that because Valieva is under the age of 16, she is considered a “protected person” under the World Anti-Doping Code and as such, should be sanctioned to a lesser degree than someone of age. In addition, because the positive sample was taken before the Winter Olympics, and she had not tested positive during the Games themselves, preventing her from participating in the Winter Games would cause “irreparable harm.” In addition, the 44-day delay in reporting her adverse test results should not be held against her to her detriment, particularly in consideration of the fact that the substance detected in the sample was “extremely low” and its performance-enhancing effects have not been proven. The World Anti-Doping Agency expressed its disappointment in the decision, noting that the World Anti-Doping Code does not permit “specific exceptions to be made in relation to mandatory provisional suspensions for ‘protected persons.’”

Do MNEs Benefit More from Foreign or Local Competition for their Emerging Market Innovation?

How do the innovation-related benefits of competition vary across foreign and local competition? Inspired by a blend of perspectives and arguments from the competition, innovation and strategic change literature, we explore which type of competition benefits advanced economy MNEs (AEMNEs) emerging market (EM) innovation performance most, when and in what pace and rhythm. We predict that local competition contributes more to AEMNEs EM innovation performance and this positive effect is strengthened by increased competition from foreign peers and at a faster pace. We also expect that competition irregularity reinforces the innovation performance-enhancing effect of local competition but diminishes that of foreign competition. We test these predictions using a sample of AEMNEs operating in the Chinese high-tech industries. Results from our multi-level analysis provide strong support for our arguments. Our findings have important implications for research on AEMNE EM innovation performance variations resulting from the heterogeneity in the sources of competitive forces and their temporal structure.

Current Injection‐Induced Performance Enhancement in n‐Type Silicon Heterojunction Solar Cells

Silicon heterojunction (SHJ) solar cells have garnered significant attention recently due to their excellent performance, benefiting from the outstanding passivation quality of intrinsic/doped hydrogenated amorphous silicon (a‐Si:H) bilayers. Herein, it is found that current injection at elevated temperatures can enhance the electrical performance of SHJ solar cells. The kinetics study clarifies that activation energy of 0.5 eV is obtained for this enhancement phenomenon. By using photoluminescence (PL) images, it is demonstrated that the performance enhancement can be mainly attributed to the reduction of electrically active defects. The underlying mechanism is focused on the diffusion and passivation effect of hydrogen, which could be valuable for understanding the kinetics of the current injection‐induced enhancement phenomenon in the SHJ cells. This approach serves as an alternative method of light soaking to reach the effect of performance enhancement of SHJ cells, making it more competitive in the photovoltaics industry.

Anabolic androgenic steroid-induced liver injury: An update.

Anabolic androgenic steroids (AASs) are a group of molecules including endogenous testosterone and synthetic derivatives that have both androgenic and anabolic effects. These properties make them therapeutically beneficial in medical conditions such as hypogonadism. However, they are commonly bought illegally and misused for their anabolic, skeletal muscle building, and performance-enhancing effects. Supraphysiologic and long-term use of AASs affects all organs, leading to cardiovascular, neurological, endocrine, gastrointestinal, renal, and hematologic disorders. Hepatotoxicity is one of the major concerns regarding AASs treatment and abuse. Testosterone and its derivatives have been most often shown to induce a specific form of cholestasis, peliosis hepatis, and hepatic benign and malignant tumors. It is currently believed that mechanisms of pathogenesis of these disorders include disturbance of antioxidative factors, upregulation of bile acid synthesis, and induction of hepatocyte hyperplasia. Most toxicity cases are treated with supportive measures and liver function normalizes with discontinuation of AAS. However, some long-term consequences are irreversible. AAS-induced liver injury should be taken in consideration in patients with liver disorders, especially with the increasing unintentional ingestion of supplements containing AAS. In this paper, we review the most current knowledge about AAS-associated adverse effects on the liver, and their clinical presentations, prevalence, and pathophysiological mechanisms.

Post-Activation Performance Enhancement: Save Time With Active Intra-Complex Recovery Intervals

This study aimed to determine whether the intra-complex active recovery within the strength-power potentiating complex will impact the upper-body post-activation performance enhancement effect and how the magnitude of this effect will change across the upper-body complex training session. Thirteen resistance-trained males [the age, body mass, height, experience in resistance training, and one-repetition maximum (1RM) in bench press were 27 ± 4 years; 92.3 ± 15.4 kg; 182 ± 6 cm; 6.4 ± 2.4 years, and 118 ± 29 kg, respectively) participated in this study. Each participant completed a baseline bench press throw performance assessment at 30% 1RM. Next, five strength-power potentiating complexes consisting of a bench press at 80% 1RM were tested until the average barbell velocity decreased by 10% as a conditioning activity, and 6 min later, a re-test of bench press throw was carried out. During one experimental session during the rest interval inside the complex, they performed swiss ball leg curls, while between the complexes, a plank exercise (PAP-A) was performed. During the second experimental session, participants performed no exercises within the strength-power potentiating complexes and between them (PAP). Under control conditions, participants ran the same protocol (as the PAP condition) without the conditioning activity (CTRL). Friedman’s test showed significant differences in peak (test = 90.634; p < 0.0001; Kendall’s W = 0.410) and average (test = 74.172; p < 0.0001; Kendall’s W = 0.336) barbell velocities during bench press throw. Pairwise comparisons indicated that the peak and average barbell velocities significantly increased in the fourth set [p = 0.022, effect size (ES) = 0.76 and p = 0.013, ES = 0.69, respectively], and the average barbell velocity was also increased in the second set (p = 0.018, ES = 0.77) in comparison to the baseline value during the PAP-A condition. Moreover, the peak barbell velocity was increased in the second (p = 0.008, ES = 0.72) and third (p = 0.019, ES = 0.76) sets compared to the baseline value during the PAP condition. This study showed that body-weight lower-body exercise as an intra-complex active recovery did not impair the upper-body post-activation performance enhancement effect across the complex training session.

Combined long-term enriched environment and caffeine supplementation improve memory function in C57Bl6 mice

Regular physical activity has been associated with healthy brain aging, reflected by beneficial effects on cognition and learning and memory. Nutritional supplements such as caffeine have been shown to act as cognitive enhancers and may possess neuroprotective properties. Interestingly, caffeine also improves athletic capabilities and is widely used by athletes because of its performance-enhancing effect, while information on potential additive beneficial effects of physical activity and caffeine on cognitive performance is scarce. In the present study, the effects of caffeine supplementation in combination with prolonged physical and cognitive stimulation in the form of the enriched environment (EE) housing for a duration of 4 months were analyzed. We demonstrate that caffeine supplementation together with prolonged environmental enrichment led to enhanced memory function, resulting in improved recognition and spatial working memory in behavioral paradigms such as the novel object recognition task or the Morris water maze in C57Bl6 wild-type mice. Mice housed under EE conditions showed increased gene expression levels of brain-derived neurotrophic factor (BDNF) in the hippocampus. The present findings underscore the potential impact of continuous physical activity in the prevention of age-related cognitive decline and may offer new options for combinatorial approaches.

Research on Mechanical and Carbonization Properties of Hybrid Fiber Iron Tailings Concrete Based on Deep Learning.

Iron tailings sand is a kind of mineral waste, and open-air storage is a common treatment method for iron tailings, which not only has a huge impact on the ecological environment but also occupies a lot of land resources. Therefore, the preparation of high-ductility fiber reinforced iron tailings concrete and its application in practical engineering structures have good application prospects. This paper is based on the deep learning research on the mechanical and carbonization properties of hybrid fiber iron tailings concrete. Therefore, tailings sands with different substitution rates, single-mixed steel fiber, and mixed steel-PVA fiber concrete were prepared in this paper. Its compressive strength, split tensile strength, axial compressive strength, elastic modulus, strain, and carbonization depth were tested. Through the existing concrete compressive stress-strain curve equations, the nonlinear calculation of each group of concrete compressive stress-strain curve equations in this paper is carried out, some parameters are determined, and the carbonation depth equation is established. The results show that, with the increase of tailings content, the properties of concrete increase first and then decrease and the addition of fibers can effectively improve the strength, elastic modulus, peak strain, and carbonization depth of concrete. However, with the increase of PVA fiber content, its performance enhancement effect decreased.

Molecular Dynamic Study of Mechanism Underlying Nature of Molecular Recognition and the Role of Crosslinker in the Synthesis of Salmeterol-Targeting Molecularly Imprinted Polymer for Analysis of Salmeterol Xinafoate in Biological Fluid.

The rational preparation of molecularly imprinted polymers (MIPs) in order to have selective extraction of salmeterol xinafoate (SLX) from serum was studied. SLX is an acting β-adrenergic receptor agonist used in the treatment of asthma and has an athletic performance-enhancing effect. Molecular dynamics were used for the simulation of the SLX-imprinted pre-polymerization system, to determine the stability of the system. The computational simulation showed that SLX as a template, 4-hydroxyethyl methacrylate (HEMA) as a monomer, and trimethylolpropane trimethacrylate (TRIM) as a crosslinker in mol ratio of 1:6:20 had the strongest interaction in terms of the radial distribution functional. To validate the computational result, four polymers were synthesized using the precipitation polymerization method, and MIP with composition and ratio corresponding with the system with the strongest interaction as an MD simulation result showed the best performance, with a recovery of 96.59 ± 2.24% of SLX in spiked serum and 92.25 ± 1.12% when SLX was spiked with another analogue structure. Compared with the standard solid phase extraction sorbent C-18, which had a recovery of 79.11 ± 2.96%, the MIP showed better performance. The harmony between the simulation and experimental results illustrates that the molecular dynamic simulations had a significant role in the study and development of the MIPs for analysis of SLX in biological fluid.

Active Relative to Passive Ischemic Preconditioning Enhances Intense Endurance Performance in Well-Trained Men.

This study tested the hypothesis of whether ischemic exercise preconditioning (IPC-Ex) elicits a better intense endurance exercise performance than traditional ischemic preconditioning at rest (IPC-rest) and a SHAM procedure. Twelve men (average V˙O2max ∼61mL·kg-1·min-1) performed 3 trials on separate days, each consisting of either IPC-Ex (3 × 2-min cycling at ∼40W with a bilateral-leg cuff pressure of ∼180mmHg), IPC-rest (4 × 5-min supine rest at 220mmHg), or SHAM (4 × 5-min supine rest at <10mmHg) followed by a standardized warm-up and a 4-minute maximal cycling performance test. Power output, blood lactate, potassium, pH, rating of perceived exertion, oxygen uptake, and gross efficiency were assessed. Mean power during the performance test was higher in IPC-Ex versus IPC-rest (+4%; P = .002; 95% CI, +5 to 18W). No difference was found between IPC-rest and SHAM (-2%; P = .10; 95% CI, -12 to 1W) or between IPC-Ex and SHAM (+2%; P = .09; 95% CI, -1 to 13W). The rating of perceived exertion increased following the IPC-procedure in IPC-Ex versus IPC-rest and SHAM (P < .001). During warm-up, IPC-Ex elevated blood pH versus IPC-rest and SHAM (P ≤ .027), with no trial differences for blood potassium (P > .09) or cycling efficiency (P ≥ .24). Eight subjects anticipated IPC-Ex to be best for their performance. Four subjects favored SHAM. Performance in a 4-minute maximal test was better following IPC-Ex than IPC-rest and tended to be better than SHAM. The IPC procedures did not affect blood potassium, while pH was transiently elevated only by IPC-Ex. The performance-enhancing effect of IPC-Ex versus IPC-rest may be attributed to a placebo effect, improved pH regulation, and/or a change in the perception of effort.

Toward a goal-based paradigm of contagion

PurposeThis study aims to extend the previous research on contagion and proposes an integrative paradigm in which consumer goals and contagion recipient factors are identified as the key variables leading to the emergence of the contagion phenomenon. When a consumer has an active goal, a product touched by goal-congruent sources leads to positive product evaluation and enhances consumer performance when the product is used.Design/methodology/approachThis research conducted five experimental studies in online and offline retail settings to examine the effect of contagion on evaluations of contagion objects and performance in goal-related tasks.FindingsAcross five studies, the authors demonstrated that the activation of a goal leads to contagion-based product evaluation and performance enhancement effects. The authors theorized and showed that the contagion-based process triggered during goal pursuit led to a more favorable evaluation of contagion products (Studies 1, 2 and 3). The authors also showed that enhanced consumers’ commitment toward a goal, which in turn led to enhanced performance in a real task that contributed to achieving one’s goal (Study 4). These effects emerged only when the object was physically touched by a goal-congruent contagion source and were more pronounced for the consumers who experience a high (vs low) degree of goal discrepancy (Study 5).Research limitations/implicationsThe current research examined the contagion phenomenon in a few predetermined goal domains (e.g. health improvement goals, career success goals, marriage success goals). Although the authors found consistent effects across different types of goals, future research can examine a more comprehensive set of consumer goals and improve the limitation of the current research to generalize the goal-based contagion phenomenon to various consumer goals.Practical implicationsThis study suggests that it is important for retailers, in particular sellers and buyers in the secondhand markets, to understand consumer goals and prepare an appropriate contagion environment for favorable evaluation of their offerings. One possible implication is that sellers may be best served as priming certain goals. The findings also indicate that secondhand sellers may be well served to emphasize seller characteristics in certain instances and de-emphasize them in others to maximize sales.Originality/valueThis research proposes a new variable, namely, goal activation, and presents an integrative contagion paradigm that not only helps explain previous research findings but also offers a new perspective on the contagion phenomenon.

Effects of Music Volume Preference on Endurance Exercise Performance.

The purpose of this study was to examine the effects of preferred versus non-preferred music volume on relative power output, trial time to completion (TTC), heart rate (HR), rate of perceived exertion (RPE), and motivation during endurance rowing exercise. Physically active females (age 18–25) volunteered to participate. In a crossover counterbalanced design, participants completed two trials: non-preferred (NPV) and preferred (PV) music volume. Participants began with a rowing warm-up at 50% of HRmax for 5 min. Following this, participants completed a 2000 m rowing time trial as quickly as possible. Relative power output, HR, and RPE were documented each minute during the exercise bout. TTC and motivation levels were documented at the cessation of exercise. Results showed that there were no significant differences between NPV and PV for relative power output (p = 0.287; d = 0.17), TTC (p = 0.816; d = 0.01), and HR (p = 0.956; d = 0.08). However, RPE was significantly lower (p = 0.002; d = 0.86) and motivation was significantly higher (p < 0.001; d = 2.14) during the PV condition versus NPV. Findings suggest that while PV does not impart performance-enhancing effects during endurance exercise compared to NPV, it may improve psychological responses related to intensity and effort which could have important implications for enduring intense exercise and training.

A meta-analysis on immediate effects of attentional focus on motor tasks performance

ABSTRACT Directing the attentional focus towards intended movement effects could enhance individual performance. This meta-analysis examines the immediate effects of an instructed external (proximal/distal) and internal attentional focus on an experimental group and a control group on their performance. A systematic review was done following the PRISMA guidelines. A total of 3833 reports were scanned. Of these, 83 were included in the systematic review, and 61 studies were included into the meta-analysis. The meta-analysis was additionally split into the original categories, which included the instructions as mentioned in the paper, and the adapted classifications, for which the instructions were reclassified based on the definition by [Wulf, G. (2013). Attentional focus and motor learning: A review of 15 years. International Review of sport and Exercise psychology, 6(1), 77–104. doii:10.1080/1750984X.2012.723728 and McNevin, N. H., Shea, C. H., & Wulf, G. (2003). Increasing the distance of an external focus of attention enhances learning. Psychological Research, 67(1), 22–29. doii:10.1007/s00426-002-0093-6]. In line with the constrained-action hypothesis, an external attentional focus instruction enhanced the immediate performance compared to an internal attentional focus instruction (SMDadapted = 0.24) and the control group (SMDadapted SMD = 0.31). Also, consistent with the constrained-action hypothesis, distal external attentional focus instructions showed performance-enhancing effects compared to proximal external attentional focus instructions (SMDadapted = 0.23). However, most comparisons showed moderate to substantial heterogeneity and wide prediction intervals. Therefore, the results cannot be generalized for all tasks and skill levels.

Pay attention! The influence of coach-, content-, and player-related factors on focus of attention statements during tennis training

ABSTRACT It is well established that adopting an external focus of attention (EF) enhances motor learning when contrasted to an internal focus (IF) or a neutral condition. Despite consistent evidence for this performance-enhancing effect of an EF, recent studies show that coaches predominantly induce an IF in the communication with athletes. It remains, however, unknown whether and to what degree coach-, content- or player-related factors have an impact on the focus of attention during youth tennis training. Therefore, we recorded all statements from 10 tennis coaches during six training sessions with a total of 87 youth athletes aged 18 years or younger. All statements were categorized according to the focus they induced (IF, EF, neutral, best place to hit the ball, mix, no focus) and the form of communication (instruction, feedback). Of the relevant statements (n = 3049), 45.1% promoted an EF, whereas 33.1% induced an IF. Evaluation of coaches-, player- and content-specific features (education, age of coach/player, training content, skill level) showed that more statements with an IF were given when training beginners. The data also show more statements with an EF for instructions (59.0%) compared to feedback (43.0%). Our results contrast with other sports where instructions with an IF predominate. Thus, instrumented sports with external targets (e.g. tennis) might be better suited for inducing an EF. The data also show that coaches are more likely to use IF when communicating with beginners. Consequently, an EF should not be induced in every possible situation, even if this is often communicated so far. Highlights This study shows for the first time that statements that induce an external focus of attention predominate in tennis. This result contrasts with results from other sports and suggests that racquet sports may be better suited for inducing an external attentional focus. This study shows that coaches adapt their communication to the performance level of their athletes. The use of an external focus of attentions predominates when working with tennis players. However, the likelihood of inducing an EF is even higher when working with skilled tennis players when compared to beginners. The way of communication (feedback vs. instruction) influences how coaches phrase their statements to athletes. The analysis revealed that coaches use more statements with an external focus of attentions for instructions compared to feedback.

Influence of advanced footwear technology on sub-2 hour marathon and other top running performances

Abstract In 2019, Eliud Kipchoge ran a sub-two hour marathon wearing Nike’s Alphafly shoes. Despite being the fastest marathon time ever recorded, it wasn’t officially recognized as race conditions were tightly controlled to maximize his success. Besides, Kipchoge’s use of Alphafly shoes was controversial, with some experts claiming that they might have provided an unfair competitive advantage. In this work, we assess the potential influence of advanced footwear technology and the likelihood of a sub-two hour marathon in official races, by studying the evolution of running top performances from 2001 to 2019 for long distances ranging from 10 km to marathon. The analysis is performed using extreme value theory, a field of statistics dealing with analysis of rare events. We find a significant evidence of performance-enhancement effect with a 10% increase of the probability that a new world record for marathon-men discipline is set in 2021. However, results suggest that achieving a sub-two hour marathon in an official race in 2021 is still very unlikely, and exceeds 10% probability only by 2025.

Effect of the combination of caffeine and taurine of different concentrations on activated B-cells

Caffeinated drinks are popular because of their mood- and performance-enhancing effects. Energy drinks in particular are advertised with these properties, with the content of caffeine and taurine being a central component of these products. However, little is known about the influence of taurine and caffeine on immune cells. This article answers the following research question: “How high is the effect of the combination of caffeine and taurine of different concentrations on activated B-cells”.Immunoglobulin production is a measure of B-cell activity. This property is determined in mouse B-cells. For this purpose, these cells are taken from the spleen of mice, induced with CD40/IL4 and the activity is checked with the aid of an immunoglobulin ELISA. Low doses of taurine and caffeine in combination do not cause any significant change in immunoglobulin production, whereas high doses (4 or 40 mg / ml) lead to cell death.

Benefits of a plant-based diet and considerations for the athlete.

Individuals may opt to follow a plant-based diet for a variety of reasons, such as religious practices, health benefits or concerns for animal or environmental welfare. Such diets offer a broad spectrum of health benefits including aiding in the prevention and management of chronic diseases. In addition to health benefits, a plant-based diet may provide performance-enhancing effects for various types of exercise due to high carbohydrate levels and the high concentration of antioxidants and phytochemicals found in a plant-based diet. However, some plant-based foods also contain anti-nutrional factors, such as phytate and tannins, which decrease the bioavailability of key nutrients, such as iron, zinc, and protein. Thus, plant-based diets must be carefully planned to ensure adequate intake and absorption of energy and all essential nutrients. The current narrative review summarizes the current state of the research concerning the implications of a plant-based diet for health and exercise performance. It also outlines strategies to enhance the bioavailability of nutrients, sources of hard-to-get nutrients, and sport supplements that could interest plant-based athletes.