Legal Performance-enhancing Drugs Alter Course and Treatment of Rhabdomyolysis-induced Acute Kidney Injury

INTRODUCTION

Rhabdomyolysis-induced acute kidney injury (RIAKI) can interrupt physical training and increase mortality in injured warfighters. The legal performance-enhancing drugs caffeine and ibuprofen, which can cause renal injury, are widely used by service members. Whether caffeine or ibuprofen affects RIAKI is unknown. Cilastatin treatment was recently identified as an experimental treatment to prevent RIAKI at injury. To determine potential interacting factors in RIAKI treatment, we test the hypothesis that caffeine and ibuprofen worsen RIAKI and interfere with treatment.

MATERIALS AND METHODS

In mice, RIAKI was induced by glycerol intramuscular injection. Simultaneously, mice received caffeine (3 mg/kg), ibuprofen (10 mg/kg), or vehicle. A second cohort received volume resuscitation (PlasmaLyte, 20 mL/kg) in addition to caffeine or ibuprofen. In a third cohort, cilastatin (200 mg/kg) was administered concurrently with drug and glycerol administration. Glomerular filtration rate (GFR), blood urea nitrogen (BUN), urine output (UOP), renal pathology, and renal immunofluorescence for kidney injury molecule 1 were quantified after 24 hours.

RESULTS

Caffeine did not worsen RIAKI; although BUN was modestly increased by caffeine administration, 24-hour GFR, UOP, and renal histopathology were similar between vehicle-treated, caffeine-treated, and caffeine + PlasmaLyte-treated mice. Ibuprofen administration greatly worsened RIAKI (GFR 14.3 ± 19.5 vs. 577.4 ± 454.6 µL/min/100 g in control, UOP 0.5 ± 0.4 in ibuprofen-treated mice vs. 2.7 ± 1.7 mL/24 h in control, and BUN 264 ± 201 in ibuprofen-treated mice vs. 66 ± 21 mg/dL in control, P < .05 for all); PlasmaLyte treatment did not reverse this effect. Cilastatin with or without PlasmaLyte did not reverse the deleterious effect of ibuprofen in RIAKI.

CONCLUSIONS

Caffeine does not worsen RIAKI. The widely used performance-enhancing drug ibuprofen greatly worsens RIAKI in mice. Standard or experimental treatment of RIAKI including the addition of cilastatin to standard resuscitation is ineffective in mice with RIAKI exacerbated by ibuprofen. These findings may have clinical implications for the current therapy of RIAKI and for translational studies of novel treatment.

Sports Medicine: Ergogenic Aids

Ergogenic aids include performance-enhancing substances, nutritional supplements, and a variety of techniques aimed to improve an athlete's exercise performance capacity. Dietary supplement consumption in athletes is common and is higher in those with desire to become Olympic or world champions. Supplements with performance benefits include caffeine, creatine, nitrate, and sodium bicarbonate. Anabolic-androgenic steroids; stimulants, such as ephedrine; and body mass builders, such as human growth hormone, are the most used performance-enhancing substances in competition. The World Anti-Doping Agency (WADA) is responsible for generating the list of banned performance-enhancing substances as well as establishing the testing standards for national and international events. Makers of dietary supplements are not required to prove the products are safe or test them for quality. Products with third-party testing certifications can help minimize the risk of ingesting contaminated or banned substances. Therapeutic use exemptions may be granted in Olympic, professional, or NCAA sports for athletes with a medical necessity for banned substances. The role of the physician or other medical professional is to guide informed decision-making.

Education Interventions to Improve Knowledge, Beliefs, Intentions and Practices with Respect to Dietary Supplements and Doping Substances: A Narrative Review

The misuse of dietary supplements and doping substances is commonly associated with toxicity, nutritional imbalances, and health and psychological consequences. This is alarming especially in light of the increasing prevalence of the use of dietary supplements and doping, particularly among young adults including athletes. There is evidence that education interventions can lead to improved knowledge, intentions, and practices. However, no review has summarized and evaluated the effectiveness of such interventions. The aim of this article is to review the characteristics, contents and effects of education interventions that were designed and implemented to improve knowledge, attitudes, beliefs and intentions with respect to the use of dietary supplements and doping agents in different populations. PubMed, Scopus, CINAHL, PsycInfo and Google Scholar were searched for English-language education interventions targeting dietary supplements and doping substances. A total of 20 articles were identified and have generally provided consistent findings. Most interventions reported a significant improvement in knowledge on dietary supplements and doping agents. Unfortunately, the heavy reliance on self-reported assessment tools limits the validity of these interventions, with almost all articles targeting athletes and adolescents.

Use of Sports Supplements in Competitive Handball Players: Sex and Competitive Level Differences

Sports supplements are commonly used by elite athletes with the main goal of enhancing sport performance. Supplements use might be substantially different depending on the sport discipline, sex, and competitive level. To date, data about prevalence and the most-commonly used supplements in handball are scarce. Thus, the aim of this investigation was to determine the patterns of supplements use by handball players of both sexes and with different competitive levels: One hundred and eighty-seven handball players (112 men and 75 women) of different competitive levels (106 professional and 81 amateur) completed a validated self-administered questionnaire about supplements use. Supplements were classified according to the categorization of the Australian Institute of Sport (AIS). Overall, 59.9% of the handball players (n = 112) declared the use of at least one supplement and there were no significant differences between men and women (58.9% vs. 61.3%, p = 0.762) nor between professional vs. amateur handball players (67.1% vs. 53.8%, p = 0.074). The most prevalent supplements were sports drinks (42.2%), followed by energy bars (35.3%) and caffeine-containing products (31.6%). However, a greater consumption of group A supplements (those with strong scientific evidence; p = 0.029) and group B supplements (those with emerging scientific support, p = 0.012) was observed in male compared to female handball players. Supplements categorized as medical supplements were more commonly consumed in professional vs. amateur players (0.48 ± 0.80 vs. 0.21 ± 0.44, supplements p < 0.006). Additionally, a higher consumption of group B supplements was observed in professional compared to amateur players (0.58 ± 0.88 vs. 0.33 ± 0.72 supplements, p = 0.015). Handball players revealed a moderate use of supplements while sex and competitive level slighted changed the pattern of supplements use. A high portion of handball players use supplements as fuel during exercise and reported the use of caffeine-containing supplements to enhance performance.

The Efficacy of Administering Fruit-Derived Polyphenols to Improve Health Biomarkers, Exercise Performance and Related Physiological Responses

Polyphenols are secondary metabolites involved in a myriad of critical processes in plants. Over recent decades, special attention has been paid to the anti-oxidative role of fruit-derived polyphenols in the human diet, with evidence supporting the contribution of polyphenols in the prevention of numerous non-communicable disease outcomes. However, due to the low concentration in biological fluids in vivo, the antioxidant properties of polyphenols seem to be related to an enhanced endogenous antioxidant capacity induced via signaling through the nuclear respiratory factor 2 pathway. Polyphenols also seem to possess anti-inflammatory and antioxidant properties and have been shown to enhance vascular function via nitric oxide mediated mechanisms. Consequently, there is rationale to support fruit-derived polyphenol supplementation to enhance exercise performance, possibly via improved muscle perfusion. Fruit-derived polyphenol supplementation in exercise studies have included a variety of fruits, e.g., New Zealand blackcurrant, pomegranate, and cherry, in the form of extracts (multicomponent or purified), juices and infusions to varying degrees of benefit. For example, research has yet to link the health-related benefits of black elderberry (Sambucus nigra L.) ingestion to exercise performance in spite of the purported health benefits associated with black elderberry provision in vitro and in vivo models, which has been attributed to their high antioxidant capacity and polyphenol content. This review summarizes the existing evidence supporting a beneficial effect of fruit-derived polyphenols on various biological processes and outlines the potential for black elderberry ingestion to improve nitric oxide production, exercise performance, and the associated physiological responses before-, during- and post-exercise.

A low-dose, 6-week bovine colostrum supplementation maintains performance and attenuates inflammatory indices following a Loughborough Intermittent Shuttle Test in soccer players

PURPOSE

The aim of the study was to investigate the effect of a 6-week, low-dose bovine colostrum (BC) supplementation on exercise-induced muscle damage (EIMD) and performance decline in soccer players following the Loughborough Intermittent Shuttle Test (LIST) during a competitive season period.

METHODS

In a double-blind, randomized, placebo-controlled design, two groups of soccer players were allocated to a 3.2 g/day of whey protein (WP, N = 8) or BC (N = 10) and performed a pre- and a post-supplementation LIST. Maximum isometric voluntary contraction, squat jump (SQJ), countermovement jump, muscle soreness, blood cell counts, creatine kinase (CK), C-reactive protein (CRP) and interleukin-6 (IL-6) were monitored for 2, 24, 48, 72 h post-LIST.

RESULTS

LIST induced transient increases in leukocytes, granulocytes, CK, muscle soreness, CRP, IL-6 and declines in lymphocytes and performance indices. Supplementation resulted in a faster recovery of SQJ, CK and CRP compared to pre-supplementation kinetics (trial × time: p = 0.001, 0.056, 0.014, respectively) and lower incremental area under the curve (iAUC) for IL-6, only in the BC group [pre-: 31.1 (6.78-46.9), post-: 14.0 (-0.16 to 23.5) pg h/ml, p = 0.034]. Direct comparison of the two groups after supplementation demonstrated higher iAUC of SQJ [WP: -195.2 (-229.0 to (-52.5)), BC: -15.8 (-93.2 to 16.8) cm h, p = 0.034], a trend for lower iAUC of CK in the BC group [WP: 18,785 (4651-41,357), BC: 8842 (4807-14,802) U h/L, p = 0.081] and a significant intervention × time interaction for CRP (p = 0.038) in favor of BC.

CONCLUSIONS

Post-exercise EIMD may be reduced and performance better maintained by a low dose of BC administration following LIST in soccer players.

l-Carnitine Supplementation in Recovery after Exercise

Given its pivotal role in fatty acid oxidation and energy metabolism, l-carnitine has been investigated as ergogenic aid for enhancing exercise capacity in the healthy athletic population. Early research indicates its beneficial effects on acute physical performance, such as increased maximum oxygen consumption and higher power output. Later studies point to the positive impact of dietary supplementation with l-carnitine on the recovery process after exercise. It is demonstrated that l-carnitine alleviates muscle injury and reduces markers of cellular damage and free radical formation accompanied by attenuation of muscle soreness. The supplementation-based increase in serum and muscle l-carnitine contents is suggested to enhance blood flow and oxygen supply to the muscle tissue via improved endothelial function thereby reducing hypoxia-induced cellular and biochemical disruptions. Studies in older adults further showed that l-carnitine intake can lead to increased muscle mass accompanied by a decrease in body weight and reduced physical and mental fatigue. Based on current animal studies, a role of l-carnitine in the prevention of age-associated muscle protein degradation and regulation of mitochondrial homeostasis is suggested.

Carbohydrate Mouth Rinse Fails to Improve Four-Kilometer Cycling Time Trial Performance

We investigated if a carbohydrate (CHO) mouth rinse may attenuate global fatigue and improve 4-km cycling time trial (TT_4km) performance. After a preliminary session, cyclists (n = 9) performed a TT_4km after a CHO or placebo (PLA) mouth rinse. Mean power output, time, and ratings of perceived exertion (RPE) were recorded throughout the TT_4km. Twitch interpolation responses (%VA; voluntary activation and ∆Tw; delta peak twitch torque) were compared pre and post TT_4km with traditional statistics and effect size (ES) analysis. Time-to-complete the 4 km and mean power output were comparable between CHO (386.4 ± 28.0 s) and PLA (385.4 ± 22.4 s). A lower central (p = 0.054) and peripheral (p = 0.02) fatigue in CHO than in PLA were suggested by an extremely-large ES in %VA (manipulation main effect: p = 0.052, d = 1.18; manipulation-by-time interaction effect: p = 0.08, d = 1.00) and an extremely, very-large ES in ∆Tw (manipulation main effect: p = 0.07, d = 0.97; time-by-manipulation interaction effect: p = 0.09, d = 0.89). The RPE increased slower in CHO than in PLA (p = 0.051; d = 0.7). The apparent reduction in global fatigue (central and peripheral) and RPE_SLOPE with only one CHO mouth rinse were not translated into improved TT_4km performance. Further tests may be required to verify if these likely differences in global fatigue might represent an edge in the short-lasting cycling time trial performance.

Effects of Antrodia camphorata and Panax ginseng supplementation on anti-fatigue properties in mice

Antrodia camphorata and Panax ginseng are well-known medicinal plants in Taiwan folk and traditional Chinese medicine, which have been reported for multifunctional bioactivities. However, there is limited evidence that a fixed combination formula of these two plant extracts is effective for the exercise improvement or anti-fatigue. We aimed to evaluate the potential beneficial effects of the mix formulation of these two herbal medicines (AG formulation) on fatigue and ergogenic functions following physiological challenge. Male Institute of Cancer Research (ICR) mice from four groups (n=10 per group) were orally administered AG formulation for 4 weeks at 0.984, 2.952 and 5.904 g/kg/day, which were designated the Vehicle, AG-1X, AG-3X and AG-6X groups, respectively. The anti-fatigue activity and exercise performance were evaluated using exhaustive swimming time, forelimb grip strength, and levels of serum lactate, ammonia, glucose, blood urea nitrogen (BUN) and creatine kinase (CK) after a swimming exercise. The exhaustive swimming time of the 1X, 3X or 6X AG group was significantly longer than that of the Vehicle group, and the forelimb grip strength of the 1X, 3X or 6X AG group was also significantly higher than that of the Vehicle group. AG supplementation also produced decreases in serum lactate, ammonia, BUN and CK activity after the swimming test, as well as increases in glucose. Therefore, the AG complex could be a potential formulation with an anti-fatigue pharmacological effect.

The Effects of Carbohydrates, in Isolation and Combined with Caffeine, on Cognitive Performance and Mood-Current Evidence and Future Directions

This review examines the effects of carbohydrates, delivered individually and in combination with caffeine, on a range of cognitive domains and subjective mood. There is evidence for beneficial effects of glucose at a dose of 25 g on episodic memory, but exploration of dose effects has not been systematic and the effects on other cognitive domains is not known. Factors contributing to the differential sensitivity to glucose facilitation include age, task difficulty/demand, task domain, and glucoregulatory control. There is modest evidence to suggest modulating glycemic response may impact cognitive function. The evidence presented in this review identifies dose ranges of glucose and caffeine which improve cognition, but fails to find convincing consistent synergistic effects of combining caffeine and glucose. Whilst combining glucose and caffeine has been shown to facilitate cognitive performance and mood compared to placebo or glucose alone, the relative contribution of caffeine and glucose to the observed effects is difficult to ascertain, due to the paucity of studies that have appropriately compared the effects of these ingredients combined and in isolation. This review identifies a number of methodological challenges which need to be considered in the design of future hypothesis driven research in this area.

Probiotic supplementation in sports and physical exercise: Does it present any ergogenic effect?

BACKGROUND

Probiotics are live microorganisms that promote health benefits to the host. Evidence indicates that some probiotic strains play an immunomodulatory role and reduce the incidence of respiratory and gastrointestinal infections in athletes and in physical activity practitioners. For this reason, probiotic supplementation could indirectly improve exercise performance. However, recent studies have observed direct ergogenic effects of probiotics, but the mechanisms of action are poorly elucidated.

OBJECTIVE

In this study, we aim to synthesize available knowledge on the effect of probiotics on physical exercise, identify the mechanisms of action by which probiotics could improve performance directly and indirectly, and verify whether probiotics have any ergogenic effect.

METHODS

The study was performed in the PubMed database in February 2017, without limitation as to the publication period. The keyword combinations used were: 'Probiotics' and 'Sports' ( n = 17 articles), 'Probiotics' and 'Exercise' ( n = 26 articles) and 'Probiotics' and 'Athletes' ( n = 11 articles).

RESULTS

Of the 16 studies evaluated, only six applied performance tests, of which only two demonstrated that probiotic supplementation increases performance, but one of them was performed with mice.

CONCLUSIONS

According to the studies evaluated, probiotic supplementation does not present ergogenic effect, however, considering the small number of studies, this subject should be better investigated.

Androgens and athletic performance of elite female athletes

PURPOSE OF REVIEW

During the last decades androgens have been used illicitly by athletes of both genders. Because of some obvious ethical limitations, mechanisms underlying the performance-enhancing effects of these hormone or drugs, as well as the magnitude of their effects, have been poorly addressed. This review aims to combine findings from field and from the laboratory to provide new insights into the ergogenic properties of endogenous or exogenous androgens on female athletes.

RECENT FINDINGS

Results obtained from recent neuropsychological studies indicated that testosterone, and not the sex chromosomes, is responsible for the sexual differentiation of visuospatial neural activation. These findings could explain how males and hyperandrogenic females benefit from androgens performance-enhancing effects in sports where visuospatial abilities are closely linked to better performance. Another study conducted on elite female athletes showed that, in some athletic events, where muscle power is of critical importance, individuals with the highest free testosterone concentration significantly outperformed competitors with the lowest free testosterone concentration.

SUMMARY

In some sport events, female athletes with high or very high androgen levels (whether it is from endogenous or exogenous origin) have an estimated competitive benefit of 2-5% over those with androgen levels within the normal female range. These findings are to be taken into account in the actual controversy about eligibility of females with hyperandrogenism to compete in women's sports.

Drug misuse in sport: a New Zealand perspective

AIMS

Drug misuse in elite sport is a world-wide phenomenon. This article explores the culture of contemporary sport, provides estimates of doping prevalence, discusses dietary supplementation and highlights major factors influencing high-performance athletes and their support personnel. The aim is to stimulate discussion, informed by the World Anti-Doping Code (WADC), which is particularly relevant to doctors caring for athletes.

METHODS

Online databases were searched for relevant peer-reviewed research from 2009 to 2015. Comparative New Zealand data have been included.

RESULTS

Estimates of the prevalence of sports doping range from less than 1% to as high as 52%, dependent upon the demographics of the identified cohort. The culture of elite sport, personal stressors, competitive demands, financial reward and the influence of an 'entourage' of support personnel were identified as critical determinants of drug misuse.

CONCLUSIONS

The culture of elite contemporary sport is seductive to many aspiring young athletes. To combat drug misuse, effective education should embody moral, ethical and clinical dangers, recognising the importance of support at times of increased athlete vulnerability. Inadvertent doping from product contamination is a recognised risk of unsupervised dietary supplementation. Doctors responsible for the care of high-performance athletes must be cognisant of these issues and the provisions of the WADC.

Ginger (Zingiber officinale) as an Analgesic and Ergogenic Aid in Sport: A Systemic Review

Ginger is a popular spice used to treat a variety of maladies, including pain. Nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently used by athletes to manage and prevent pain; unfortunately, NSAIDs contribute to substantial adverse effects, including gastrointestinal (GI) dysfunction, exercise-induced bronchoconstriction, hyponatremia, impairment of connective tissue remodeling, endurance competition withdrawal, and cardiovascular disease. Ginger, however, may act as a promoter of GI integrity and as a bronchodilator. Given these potentially positive effects of ginger, a systematic review of randomized trials was performed to assess the evidence for ginger as an analgesic and ergogenic aid for exercise training and sport. Among 7 studies examining ginger as an analgesic, the evidence indicates that roughly 2 g·d(-1) of ginger may modestly reduce muscle pain stemming from eccentric resistance exercise and prolonged running, particularly if taken for a minimum of 5 days. Among 9 studies examining ginger as an ergogenic aid, no discernable effects on body composition, metabolic rate, oxygen consumption, isometric force generation, or perceived exertion were observed. Limited data suggest that ginger may accelerate recovery of maximal strength after eccentric resistance exercise and reduce the inflammatory response to cardiorespiratory exercise. Major limitations to the research include the use of untrained individuals, insufficient reporting on adverse events, and no direct comparisons with NSAID ingestion. While ginger taken over 1-2 weeks may reduce pain from eccentric resistance exercise and prolonged running, more research is needed to evaluate its safety and efficacy as an analgesic for a wide range of athletic endeavors.

Using the prototype willingness model to predict doping in sport

To enable preventive measures to be designed, it is important to identify modifiable distal and proximal factors underlying doping behavior. This study investigated aspects of the prototype willingness model in relation to doping. A cross-sectional study was conducted involving 729 competitive athletes. Following ethical approval, athletes (mean age = 28.8 ± 10.1 years; 63% male) completed an online questionnaire, which assessed doping-related attitudes, norms, prototype perceptions, outcome expectancies, and behavioral willingness. Using hierarchical multiple regression analysis, 54.4% of the total variance in willingness to dope was explained. Specifically, past doping, attitudes, and favorability of performance enhancing substance user prototypes were the strongest unique predictors of willingness to dope. Athletes appeared most willing to dope if they were to suffer an injury, a dip in performance, or think others are doping and getting away with it. National-level athletes displayed significantly greater willingness to dope (Kruskal-Wallis γ2 = 35.9, P < 0.001) and perceived themselves as significantly more similar to a doper (Kruskal-Wallis γ2 = 13.4, P = 0.004) than athletes competing at any other level. The findings highlight the importance of extending anti-doping provision beyond elite-level sport and the need to target athletes' doping-related perceptions.

Acute effects of a dietary non-starch polysaccharide supplement on cognitive performance in healthy middle-aged adults

OBJECTIVE

Certain plant polysaccharides may provide psychological health benefits. The aim of this study was to evaluate whether they can acutely improve mood and cognitive function.

METHOD

In a randomized, double-blind, placebo-controlled, between subjects design trial, 73 middle-aged adults consumed 4 g of a proprietary mixture of non-starch polysaccharides (NSPs) (Ambrotose® complex), a rice flour placebo, or a sucrose control. Participants completed testing at baseline and 30 minutes post-consumption. Acute effects of consumption on mood, cognition, and blood glucose were evaluated during mental tests designed to induce mental fatigue.

RESULTS

Significant improvement in recognition and working memory performance was observed in the group that consumed NSP compared with placebo or sucrose. Improvements in memory performance following NSP intake were independent of changes in blood glucose.

DISCUSSION

This is the first report of acute behavioural improvement following plant polysaccharide intake in healthy middle-aged adults under conditions of mental fatigue. The findings suggest that certain NSP may enhance memory performance through mechanisms other than elevated blood glucose.

Impact of contextual factors and substance characteristics on perspectives toward cognitive enhancement

Enhancing cognitive performance with substances–especially prescription drugs–is a fiercely debated topic among scholars and in the media. The empirical basis for these discussions is limited, given that the actual nature of factors that influence the acceptability of and willingness to use cognitive enhancement substances remains unclear. In an online factorial survey, contextual and substance-specific characteristics of substances that improve academic performance were varied experimentally and presented to respondents. Students in four German universities rated their willingness to use and moral acceptance of different substances for cognitive enhancement. We found that the overall willingness to use performance enhancing substances is low. Most respondents considered the use of these substances as morally unacceptable. Situational influences such as peer pressure, policies concerning substance use, relative performance level of peers, but also characteristics of the substance, such as perceptions of substance safety, shape the willingness and acceptability of using a substance to enhance academic performance. Among the findings is evidence of a contagion effect meaning that the willingness was higher when the respondents have more CE drug users in their social network. We also found deterrence effects from strong side effects of using the substance, as well as from policy regulations and sanctions. Regulations might activate social norms against usage and sanctions can be seen as costly to users. Moreover, enhancement substances seem to be most tempting to low performers to catch up with others compared to high performers. By identifying contextual factors and substance characteristics influencing the willingness and acceptability of cognitive enhancers, policy approaches could consider these insights to better manage the use of such substances.

Treating impaired cognition in schizophrenia: the case for combining cognitive-enhancing drugs with cognitive remediation

Cognitive impairment is a well-documented feature of schizophrenia and represents a major impediment to the functional recovery of patients. The therapeutic strategies to improve cognition in schizophrenia have either used medications (collectively referred to as 'cognitive-enhancing drugs' in this article) or non-pharmacological training approaches ('cognitive remediation'). Cognitive-enhancing drugs have not as yet been successful and cognitive remediation has shown modest success. Therefore, we may need to explore new therapeutic paradigms to improve cognition in schizophrenia. The optimal approach may require a combination of cognitive-enhancing drugs with cognitive remediation. We review the available data from animal and human studies that provide the conceptual basis, proof-of-concept and illustrations of success of such combination strategies in experimental and clinical paradigms in other conditions. We address the major design issues relevant to the choice of the cognitive-enhancing drugs and cognitive remediation, as well as the timing and the duration of the intervention as will be relevant for schizophrenia. Finally, we address the practical realities of the development and testing of such combined approaches in the real-world clinical situation and conclude that while scientifically attractive, there are several practical difficulties to be overcome for this approach to be clinically feasible.

Differences between synaptic plasticity thresholds result in new timing rules for maximizing long-term potentiation

The fundamental observation that the temporal spacing of learning episodes plays a critical role in the efficiency of memory encoding has had little effect on either research on long-term potentiation (LTP) or efforts to develop cognitive enhancers. Here we review recent findings describing a spaced trials phenomenon for LTP that appears to be related to recent evidence that plasticity thresholds differ between synapses in the adult hippocampus. Results of tests with one memory enhancing drug suggest that the compound potently facilitates LTP via effects on 'high threshold' synapses and thus alters the temporally extended timing rules. Possible implications of these results for our understanding of LTP substrates, neurobiological contributors to the distributed practice effect, and the consequences of memory enhancement are discussed. This article is part of a Special Issue entitled 'Cognitive Enhancers'.

Andrological aspects of physical exercise and sport medicine

Appropriate physical activity is one of the bases of healthy lifestyle. In fact, physical exercise and playing sport may be associated with both improvements and injury to both general and reproductive health. A biologically normal testosterone secretion appears fundamental in males to guarantee both a physiological exercise adaptation and safe sport participation. The reproductive system is highly sensitive to the effects of exercise-related stress and the reproductive hormones may both increase and decrease after different acute or chronic exercises. Exercise and sport participation may positively or negatively influence andrological health status depending on the type, intensity and duration of performed physical activity and on individual health status. In addition, prohibited substances administration (e.g. androgenic-anabolic steroids, and so forth) in competitive and non-competitive athletes represents the main cause of iatrogenic andrological diseases. Preventing and treating andrological problems in active healthy and unhealthy individuals is as important as promoting a correct lifestyle. Physicians need to be educated on the relationships between the male reproductive system and sport participation and on the great role of the pre-participation physical examination in the prevention of andrological diseases.

Effect of seabuckthorn (Hippophae rhamnoides ssp. sinensis) leaf extract on the swimming endurance and exhaustive exercise-induced oxidative stress of rats

BACKGROUND

Seabuckthorn (SBT) leaves have significant antioxidant, immunomodulatory and anti-inflammatory properties. The objective of this study was to assess the anti-fatigue, antioxidant and tissue-protective properties of aqueous lyophilised extracts of SBT dried leaves in the hearts of Wistar male rats undergoing exhaustive physical exercise. Doses of 50, 200 and 800 mg kg⁻¹ body weight (BW) day⁻¹ were given orally for 1 week. A week later the rats were forced to swim in barrels until they were exhausted. The times were noted to establish the effective dose of the extracts in rats. After establishing the effective dose, the rats were then sacrificed and assessed for various biochemical parameters.

RESULTS

SBT leaf aqueous extracts (200 and 800 mg kg⁻¹ BW) markedly prolonged the swim time of rats. Supplementation with SBT leaf aqueous extracts helped reduce the exhaustive exercise-induced increase in malondialdehyde level and selenium-dependent glutathione peroxidase activity. Alanine aminotransferase and creatine kinase levels were lowered in the exhaustive exercise with SBT treatment group (E + SBT) compared with the exhaustive exercise group (E).

CONCLUSION

The findings suggest that SBT leaf aqueous extract supplements can enhance exercise capacity and protect against oxidative damage caused by exhaustive exercise in rats.

Vitamins and psychological functioning: a mobile phone assessment of the effects of a B vitamin complex, vitamin C and minerals on cognitive performance and subjective mood and energy

OBJECTIVES

Despite being widely consumed, the effects of multi-vitamin supplements on psychological functioning have received little research attention.

METHODS

Using a mobile phone testing paradigm, 198 males (30-55 years) in full-time employment took part in this randomised, placebo-controlled, double-blind, parallel-groups trial assessing the effects of a multi-vitamin/mineral on cognitive performance and psychological state/mood. Participants completed two cognitive tasks and a number of visual analogue scales (VAS) before and after a full day's work, on the day before, and 7, 14, 21 and 28 days after, commencing their treatment.

RESULTS

Participants in the vitamin/mineral group rated themselves as having greater 'physical stamina' across assessments and weeks. They also rated themselves as having had greater 'concentration' and 'mental stamina' during the working day at the assessment carried out after a day's work, but not at the time of the assessment completed prior to work. Participants in this group also reported greater subjective 'alertness' on Bond-Lader mood scales during the post-work assessment on day 14 and both the pre and post-work assessments on day 28.

CONCLUSIONS

These findings complement the results from the laboratory-based, randomised-controlled trial in the same cohort and suggest that healthy members of the general population may benefit from augmented levels of vitamins/minerals via direct dietary supplementation.