The use of dietary supplements by athletes

Phytoplankton Supplementation Lowers Muscle Damage and Sustains Performance across Repeated Exercise Bouts in Humans and Improves Antioxidant Capacity in a Mechanistic Animal

The purpose of this study was to investigate the impact of antioxidant-rich marine phytoplankton supplementation (Oceanix, OCX) on performance and muscle damage following a cross-training event in endurance-trained subjects. Additionally, an animal model was carried out to assess the effects of varying dosages of OCX, with exercise, on intramuscular antioxidant capacity.

METHODS

In the human trial, endurance-trained subjects (average running distance = 29.5 ± 2.6 miles × week^-1) were randomly divided into placebo (PLA) and OCX (25 mg) conditions for 14 days. The subjects were pre-tested on a one-mile uphill run, maximal isometric strength, countermovement jump (CMJ) and squat jump (SJ) power, and for muscle damage (creatine kinase (CK)). On Day 12, the subjects underwent a strenuous cross-training event. Measures were reassessed on Day 13 and 14 (24 h and 48 h Post event). In the animal model, Wistar rats were divided into four groups (n = 7): (i) Control (no exercise and placebo (CON)), (ii) Exercise (E), (iii) Exercise + OCX 1 (Oceanix, 2.55 mg/day, (iv) Exercise + OCX 2 (5.1 mg/day). The rats performed treadmill exercise five days a week for 6 weeks. Intramuscular antioxidant capacity (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px)) and muscle damage (CK and myoglobin (MYOB) were collected. The data were analyzed using repeated measures ANOVA and t-test for select variables. The alpha value was set at p < 0.05.

RESULTS

For the human trial, SJ power lowered in PLA relative to OCX at 24 h Post (-15%, p < 0.05). Decrements in isometric strength from Pre to 48 h Post were greater in the PLA group (-12%, p < 0.05) than in the OCX. Serum CK levels were greater in the PLA compared to the OCX (+14%, p < 0.05). For the animal trial, the intramuscular antioxidant capacity was increased in a general dose-dependent manner (E + Oc2 > E + Oc1 > E > CON). Additionally, CK and MYOB were lower in supplemented compared to E alone.

CONCLUSIONS

Phytoplankton supplementation (Oceanix) sustains performance and lowers muscle damage across repeated exercise bouts. The ingredient appears to operate through an elevating oxidative capacity in skeletal muscle.

Nowhere to hide: The significant impact of coronavirus disease 2019 (COVID-19) measures on elite and semi-elite South African athletes

OBJECTIVES

To describe the perceptions of South African elite and semi-elite athletes on return to sport (RTS); maintenance of physical conditioning and other activities; sleep; nutrition; mental health; healthcare access; and knowledge of coronavirus disease 2019 (COVID-19).

DESIGN

Cross- sectional study.

METHODS

A Google Forms survey was distributed to athletes from 15 sports in the final phase (last week of April 2020) of the level 5 lockdown period. Descriptive statistics were used to describe player demographic data. Chi-squared tests investigated significance (p<0.05) between observed and expected values and explored sex differences. Post hoc tests with a Bonferroni adjustment were included where applicable.

RESULTS

67% of the 692 respondents were males. The majority (56%) expected RTS after 1-6 months. Most athletes trained alone (61%; p<0.0001), daily (61%; p<0.0001) at moderate intensity (58%; p<0.0001) and for 30-60min (72%). During leisure time athletes preferred sedentary above active behaviour (p<0.0001). Sleep patterns changed significantly (79%; p<0.0001). A significant number of athletes consumed excessive amounts of carbohydrates (76%; p<0.0001; males 73%; females 80%). Many athletes felt depressed (52%), and required motivation to keep active (55%). Most had access to healthcare during lockdown (80%) and knew proceedings when suspecting COVID-19 (92%).

CONCLUSIONS

COVID-19 had physical, nutritional and psychological consequences that may impact on the safe RTS and general health of athletes. Lost opportunities and uncertain financial and sporting futures may have significant effects on athletes and the sports industry. Government and sporting federations must support athletes and develop and implement guidelines to reduce the risk in a COVID-19 environment.

The influence of lifestyle on consumer behavior and decision making in research aimed at protein bars

We live in an era when all circumstances on the market are changing rapidly, which leads consumers (even, if they are not aware of it) to certain behaviour that affects their daily activities. Lifestyle can be described as someone's way of living or the things that a person or a particular group of people usually do. It is included among the modern elements of consumer behaviour and also affects an individual´s decision-making process. The concerns over obesity and dangerous food ingredients have prompted a “healthy lifestyle” to become the latest trend in marketing. Therefore, the regular exercising, the reduction of stress, drinking enough water, and eating nutritious food takes on its importance. The main objective of the paper is to assess the consumer behaviour on the market of a selected food commodity. For this purpose, protein bars, which are part of diet not only of athletes but also of ordinary consumers, have been chosen. To achieve this main goal, a questionnaire was designed and data were collected from the respondents of the different age groups in the Slovak Republic. Based on the primary results, the authors of the paper can claim that more than 60% of the respondents try intentionally to choose better options of food as they want to live healthy. For a deeper analysis, the assumptions were formulated and subsequently verified by the Pearson Chi-square test of independence and Kolmogorov-Smirnov test. The paper provides useful information on consumer behaviour that can help not only producers and retailers but also to consumers themselves.

Testosterone Imposters: An Analysis of Popular Online Testosterone Boosting Supplements

INTRODUCTION

Testosterone-boosting supplements (T-Boosters) are prominently featured on Amazon.com, with numerous dedicated pages and claims that they "naturally" increase testosterone levels.

AIM

To evaluate the highest rated and frequently reviewed T-Boosters on Amazon.com to facilitate patient counseling regarding marketing myths, T-Booster formulations, and evidence for efficacy and safety.

METHODS

The Amazon marketplace was queried using the key words "testosterone" + "booster," with default search settings and ranking items based on relevance. The top 5 T-Boosters identified on July 22, 2018, were reviewed based on price, ratings, reviews, manufacturer details, and ingredients. Consumer reviews were categorized using core themes in the Androgen Deficiency in the Aging Male (ADAM) questionnaire as a proxy to understand T-Booster efficacy and reanalyzed after filtration of untrustworthy comments using ReviewMeta.com, a proprietary Amazon customer review analysis software.

MAIN OUTCOME MEASURES

Quantitative and qualitative evaluation of T-Boosters on Amazon.com was performed.

RESULTS

The top 5 T-Boosters had an average ± SD of 2,761 ± 5,112 reviews and a rating of 4.56 ± 0.25 stars. 19 unique ingredients were identified across these T-Boosters, and literature review revealed 191 studies involving the 10 most common ingredients, of which 19% involved human subjects, 53% animal models, 15% in vitro studies, and 12% case reports or review articles. Among 37 human studies, 30% observed an increase in T levels, 3% a decrease, 46% no effect, and 22% were indeterminate. Analysis of top customer reviews from the first 2 pages of reviews for each supplement revealed differences in the ADAM score before and after ReviewMeta.com filtration. After filtration, there was a 91% decrease in users reporting increased libido, a 59% decrease in reports of increased energy, a 93% decrease in reports of improved strength/endurance, a 60% decrease in reports of improved erections, an elimination of reports of improved work performance, a 67% decrease in reports of improved sleep, and an 89% decrease in reports of improved sports ability.

CLINICAL IMPLICATIONS

Our study can serve as a guide for providers to counsel patients about the efficacy of popular online T-Boosters as well as the prevalence of disingenuous reviews associated with these products on online marketplaces like Amazon.com.

STRENGTHS & LIMITATIONS

Strengths include the novel approach to assess consumers' perceptions and satisfaction of T-Boosters, as well as summary information that clinicians can provide patients. Limitations include selection bias, a small number of supplements analyzed, and the proprietary nature of the Amazon review analysis software.

CONCLUSION

T-Boosters are easily available online. Our investigation revealed that limited human studies have evaluated T-Boosters, resulting in no definitive findings of efficacy. In the absence of additional human studies, patients should be cautioned before considering T-Boosters, given the availability of highly effective therapies approved by the Food and Drug Administration. Balasubramanian A, Thirumavalavan N, Srivatsav A, et al. Testosterone Imposters: An Analysis of Popular Online Testosterone Boosting Supplements. J Sex Med 2019;16:203-212.

Whey protein isolate or concentrate combined with concurrent training does not augment performance, cardiorespiratory fitness, or strength adaptations

BACKGROUND

Protein supplementation alters both strength and endurance training adaptations individually; however less is known regarding protein supplementation during concurrent training. The primary purpose of this study was to investigate the effects of whey protein supplementation during six weeks of concurrent training on performance, cardiorespiratory fitness, and maximal strength adaptations, as well as acute hormonal and immune responses. A secondary purpose was to explore the effects of two types of whey protein powders on these latter variables.

METHODS

Thirty-one participants were randomly assigned to supplement with a placebo (PLA; N.=10), whey protein isolate (WPI; N.=10), or whey protein concentrate (WPC; N.=11) in addition to their habitual diet. Total protein intake was 1.2, 3.5, and 3.5 g/kg/day for PLA, WPI, WPC groups, respectively. Exercise testing was performed before and after 6 weeks of concurrent training. Blood samples were obtained at rest, and 5 and 60 minutes after a simulated 2000 m rowing race prior to and after training.

RESULTS

There were similar but significant improvements in cardiorespiratory fitness (PLA +7.5%; WPI +3.9%; WPC +6.9%), upper body strength (PLA +5.5%; WPI +5.1%; WPC +6.7%), lower body strength (PLA +13.6%; WPI +9.4%; WPC +14.1%) and 2000m rowing performance (PLA -2.5%; WPI -2.3%; WPC -2.3%) in all groups, P<0.05. As well, hormonal and immune responses to acute exercise were similar over time and between groups.

CONCLUSIONS

Whey protein supplementation did not differentially influence performance, cardiorespiratory fitness, upper and lower body strength, immune or hormonal adaptations following 6 weeks of concurrent training.

Toward Prevention of Doping in Youth Sport: Cross-Sectional Analysis of Correlates of Doping Tendency in Swimming

Doping is recognized as one of the most important problems in sports, but a limited number of studies have investigated doping problems in youth athletes. This study aimed to evaluate doping tendency (potential doping behavior (PDB)) and correlates of PDB in youth age swimmers. The participants were 241 competitive swimmers (131 females; 15.3 ± 1.1 years of age, all under 18 years old). Variables included predictors and PDB (criterion). Predictors consisted of sociodemographic factors (gender and age), sport-related variables (i.e., experience in swimming and sport achievement), variables explaining coaching strategy and training methodology, consumption of dietary supplements (DS), knowledge about doping, and knowledge about sports nutrition and DS (KSN). In addition to the descriptive statistics and differences between genders, a multinomial regression using PDB as the criterion (negative-, neutral-, or positive-PDB, with a negative-PDB as the reference value) was calculated to define associations between predictors and criterion. With only 71% of swimmers who declared negative-PDB results indicated an alarming figure. Boys with better KSN were more negatively oriented toward positive-PDB (OR: 0.77, 95%CI: 0.60–0.95). In girls, lower competitive achievement was evidenced as a risk factor for neutral-PDB (OR: 0.39, 95%CI: 0.24–0.63). Also, higher neutral-PDB (OR: 0.88, 95%CI: 0.81–0.96) and positive-PDB (OR: 0.90, 95%CI: 0.83–0.99) were identified in girls who began with intensive training in younger age. Because of the alarming figures of PDB, there is an evident need for the development of systematic antidoping educational programs in youth swimming. In doing so, focus should be placed on girls who began intensive training at an earlier age and those who did not achieve high competitive results.

Prevalence and patterns of dietary supplement use in elite Spanish athletes

BACKGROUND

Dietary supplementation is a common strategy to achieve a specific health status or performance benefit. Several investigations have focused on the prevalence of dietary supplement use by athletes. However, information on how athletes manage the use and purchase of dietary supplements is scarce.

METHODS

Five hundred and twenty-seven high-performance athletes (346 males and 181 females), participating in individual and team sports, completed a validated questionnaire about use and purchase patterns of dietary supplements. The dietary supplements were categorized according to the International Olympic Committee (IOC) consensus.

RESULTS

Sixty four percent of the athletes (n = 337) used dietary supplements (median = 3; range 1 to 12). Age, sex, type of sport, level of competition, and professionalism influenced the prevalence of dietary supplement use (all p < 0.05). The most prevalent dietary supplement consumed was proteins (41%; n = 137), followed by amino acids/BCAA-based supplements (37%; n = 124). Additionally, as per group of supplements according to IOC consensus, 18% of the supplements were rated as having a low level of scientific evidence (e.g., glutamine, HMB, L-carnitine, etc). Most athletes (45%, n = 152) purchased dietary supplements in a store and 24% (n = 81) obtained them from a sponsor. Most athletes also (42%, n = 141) reported a self-organization of supplementation and did not consult with any professional. Last, 81% (n = 273) of athletes consuming supplements did not know any platform to check supplement safety/quality. For those who do not use dietary supplements (36% of the total sample, n = 190), most reported that they do not consider supplements necessary (72%, n = 137).

CONCLUSION

Dietary supplementation appears to be widely used in sport with a considerable proportion of athletes consuming supplements with low level of scientific evidence. Additionally, athletes seem to rely on inadequate sources of information and may be largely unaware of sources to detect supplement contamination.

What drives athletes toward dietary supplement use: objective knowledge or self-perceived competence? Cross-sectional analysis of professional team-sport players from Southeastern Europe during the competitive season

BACKGROUND

Issues related to knowledge of nutrition and dietary supplementation (DS) are understudied in professional athletes. This study aimed to examine the possible association between knowledge of nutrition and DS (KN&DS) and dietary supplement use (DSU) among professional athletes involved in team sports.

METHODS

The sample comprised professional team-sport athletes (N = 912, age: 22.11 ± 3.37 years, 356 females) involved in four Olympic sports: basketball (N = 228), soccer (N = 324), volleyball (N = 154), and handball (N = 206). The participants were tested by previously validated questionnaires to examine their self-perceived competence on nutrition and DS (S/KN&DS), their objectively evaluated (tested) KN&DS (O/KN&DS), sociodemographic and sport-specific variables (predictors), and DSU (criterion). Associations between the predictors and the criterion (No-DSU - Irregular-DSU - Regular-DSU) were determined by multinomial regression analysis for the total sample and separately for the studied sports.

RESULTS

DSU was found to be less prevalent in older and more successful players. The O/KN&DS and S/KN&DS were positively correlated with DSU, but S/KN&DS was a stronger predictor of DSU than O/KN&DS. Sport-specific associations between predictors and criterion were identified, with stronger correlations in sports with a higher prevalence of DSU.

CONCLUSIONS

Due to the low correlations between O/KN&DS and S/KN&DS in the studied players, this study highlights the necessity for more frequent monitoring of biomarkers of nutritional status and its usage by coaches and practitioners to provide quantitative instruction.

Recreational and ergogenic substance use and substance use disorders in elite athletes: a narrative review

BACKGROUND

Substances from various classes may be used for recreational purposes, self-treatment or to boost performance. When substance use shifts from occasional to regular, heavy or hazardous use, positive and negative effects can develop that vary by substance class and athlete. Regular use of recreational or performance enhancing substances can lead to misuse, sanctions or use disorders.

OBJECTIVE

To review the prevalence, patterns of use, risk factors, performance effects and types of intervention for all classes of recreational and performance enhancing substances in elite athletes by sport, ethnicity, country and gender.

METHODS

A comprehensive search was conducted to identify studies that compared the prevalence and patterns of substance use, misuse and use disorders in elite athletes with those of non-athletes and provided detailed demographic and sport variations in reasons for use, risk factors and performance effects for each main substance class.

RESULTS

Alcohol, cannabis, tobacco (nicotine) and prescribed opioids and stimulants are the most commonly used substances in elite athletes, but generally used at lower rates than in non-athletes. In contrast, use/misuse rates for binge alcohol, oral tobacco, non-prescription opioids and anabolic-androgenic steroids are higher among athletes than non-athletes, especially in power and collision sports. Cannabis/cannabinoids seem to have replaced nicotine as the second most commonly used substance.

CONCLUSIONS

Substance use in elite athletes varies by country, ethnicity, gender, sport and competitive level. There are no studies on substance use disorder prevalence in elite male and female athletes and few studies with direct comparison groups.

SPRINTING. . . Dietary Approaches to Optimize Training Adaptation and Performance

Although sprint athletes are assumed to primarily be interested in promoting muscle hypertrophy, it is the ability to generate explosive muscle power, optimization of power-to-weight ratio, and enhancement of anaerobic energy generation that are key outcomes of sprint training. This reflects the physique of track sprinters, being characterized as ecto-mesomorphs. Although there is little contemporary data on sprinters dietary habits, given their moderate energy requirements relative to body mass, a carbohydrate intake within the range of 3-6 g·kg^-1·day^-1 appears reasonable, while ensuring carbohydrate availability is optimized around training. Similarly, although protein needs may be twice general population recommendations, sprint athletes should consume meals containing ∼0.4 g/kg high biological value protein (i.e., easily digested, rich in essential amino acids) every 3-5 hr. Despite the short duration of competitions and relative long-recovery periods between races, nutrition still plays an important role in sprint performance. As energy expenditure moderates during competition, so too should intake of energy and macronutrients to prevent unwanted weight gain. Further adjustments in macronutrient intake may be warranted among athletes contemplating optimization of power-to-weight ratio through reductions in body fat prior to the competitive season. Other novel acute methods of weight loss have also been proposed to enhance power-to-weight ratio, but their implementation should only be considered under professional guidance. Given the metabolic demands of sprinting, a few supplements may be of benefit to athletes in training and/or competition. Their use in competition should be preceded with trialing in training to confirm tolerance and perceived ergogenic potential.

Protein supplement consumption is linked to time spent exercising and high-protein content foods: A multicentric observational study

The main aim of this study is to analyze if protein supplement consumption and food patterns vary across three geographical regions and secondly to identify possible factors that increase the likelihood of ingesting protein supplements. A total of 916 responses from gym users of 3 countries (Italy, Turkey and UK) were entered for analysis. Questions were related to supplement consumption (protein and other supplements), food intake and training habits. A descriptive analysis, analysis of variance (ANOVA), and logistic regression were performed. No differences were found across groups regarding: prevalence of protein supplement consumption, typology of other ingested supplement and food intake. No relation was found between level of education (r = .12) or geographical region (r = .16) and protein consumption. The analysis showed that the coach is the main source of suggestion for the intake of protein supplements (52.3%). The logistic regression model highlighted that gym users who exercised more (OR 1.51, p < 0.001) and consumed higher quantities of chicken (OR 1.39, p < 0.001) eggs (OR 1.18, p < 0.001) and canned tuna (OR 1.15, p < 0.05) were more likely to use protein supplements. Geographical area does not seem to influence the supplementation pattern. Time spent exercising and high protein foods are factors associated with protein supplement consumption.

Comparison of Pro-Regenerative Effects of Carbohydrates and Protein Administrated by Shake and Non-Macro-Nutrient Matched Food Items on the Skeletal Muscle after Acute Endurance Exercise

Physical performance and regeneration after exercise is enhanced by the ingestion of proteins and carbohydrates. These nutrients are generally consumed by athletes via whey protein and glucose-based shakes. In this study, effects of protein and carbohydrate on skeletal muscle regeneration, given either by shake or by a meal, were compared. 35 subjects performed a 10 km run. After exercise, they ingested nothing (control), a protein/glucose shake (shake) or a combination of white bread and sour milk cheese (food) in a randomized cross over design. Serum glucose (n = 35), serum insulin (n = 35), serum creatine kinase (n = 15) and myoglobin (n = 15), hematologic parameters, cortisol (n = 35), inflammation markers (n = 27) and leg strength (n = 15) as a functional marker were measured. Insulin secretion was significantly stimulated by shake and food. In contrast, only shake resulted in an increase of blood glucose. Food resulted in a decrease of pro, and stimulation of anti-inflammatory serum markers. The exercise induced skeletal muscle damage, indicated by serum creatine kinase and myoglobin, and exercise induced loss of leg strength was decreased by shake and food. Our data indicate that uptake of protein and carbohydrate by shake or food reduces exercise induced skeletal muscle damage and has pro-regenerative effects.

Whey Protein Isolate Supplementation While Endurance Training Does Not Alter Cycling Performance or Immune Responses at Rest or After Exercise

This study examined whey protein isolate supplementation combined with endurance training on cycling performance, aerobic fitness and immune cell responses. Eighteen male cyclists were randomly assigned to either placebo (PLA) or whey protein supplementation (WS; 1.0 g·kg body mass⁻¹·d⁻¹ in addition to their dietary intake). Both groups completed the identical endurance training program, 4 days per week for 6 weeks. Blood samples were obtained at rest and after 5 and 60 min of recovery from a simulated 40 km cycling time trial (TT) and were repeated after training. Baseline dietary intake of protein prior to supplementation was 1.52 ± 0.45 and 1.46 ± 0.44 g·kg body mass⁻¹·d⁻¹ for the WS and PLA groups, respectively. There were similar improvements in TT performance (WS: 71.47 ± 12.17 to 64.38 ± 8.09 min; PLA: 72.33 ± 12.79 to 61.13 ± 8.97 min), and peak oxygen uptake (WS: 52.3 ± 6.1 to 56.1 ± 5.4 mL·kg⁻¹·min⁻¹; PLA: 50.0 ± 7.1 to 54.9 ± 5.1 mL·kg⁻¹·min⁻¹) after training in both groups. White blood cells (WBC) and neutrophil counts were elevated 5 min after the TT and further increased after 60 min (P < 0.05). The exercise-induced increase in WBC and neutrophil counts at 5 and 60 min after the TT were attenuated after training compared to before training (P < 0.05). Lymphocytes increased 5 min after the TT and decreased below rest after 60 min of recovery (P < 0.05). Following training lymphocytes were lower after 60 min of recovery compared to before training. There was no change in natural killer cell activity with exercise, training or between groups. It was concluded that whey protein isolate supplementation while endurance training did not differentially change cycling performance or the immune response at rest or after exercise. However, endurance training did alter performance, aerobic fitness and some post exercise immune cell counts.

Vitamin A decreases the anabolic bone response to mechanical loading by suppressing bone formation

Increased vitamin A consumption is associated with decreased cortical bone mass and increased fracture risk in humans. Rodent studies have demonstrated that hypervitaminosis A increases cortical bone resorption, whereas the importance of the effects on bone formation is less well defined. We used an experimental model of increased bone formation by loading of the tibiae to investigate the effect of vitamin A on bone formation. Control [retinol activity equivalents (RAE) 4.5 µg/g chow] or vitamin A (RAE 60 µg/g chow) diets were given to female C57BL/6N mice for 4 wk, after which the tibiae were subjected to axial loading on alternate days for 2 wk, while the diets were continued. Vitamin A inhibited the loading-induced increase in trabecular and cortical bone volume. This was attributed to inhibition of loading-induced increase in osteoblast number and activity, and expression of osteoblastic genes Sp7, Alpl, and Col1a1 in cortical bone. Vitamin A, loading, and combination thereof also resulted in site-specific effects on bone composition measured by Raman spectroscopy. In summary, a clinically relevant dose of vitamin A suppresses the loading-induced gain of bone mass by decreasing bone formation. These observations may have implications for regulation of bone mass caused by physical activity and the risk of osteoporosis in humans.-Lionikaite, V., Henning, P., Drevinge, C., Shah, F. A., Palmquist, A., Wikström, P., Windahl, S. H., Lerner, U. H. Vitamin A decreases the anabolic bone response to mechanical loading by suppressing bone formation.

Dietary intake of branched-chain amino acids in a mouse model of Alzheimer's disease: Effects on survival, behavior, and neuropathology

Introduction

High levels of plasmatic branched-chain amino acids (BCAA), commonly used as dietary supplements, are linked to metabolic risk factors for Alzheimer's disease (AD). BCAA directly influence amino acid transport to the brain and, therefore, neurotransmitter levels. We thus investigated the impact of BCAA on AD neuropathology in a mouse model.

Methods

3xTg-AD mice were fed either a control diet or a high-fat diet from 6 to 18 months of age. For the last 2 months, dietary BCAA content was adjusted to high (+50%), normal (+0%), or low (−50%).

Results

Mice fed a BCAA-supplemented high-fat diet displayed higher tau neuropathology and only four out of 13 survived. Mice on the low-BCAA diet showed higher threonine and tryptophan cortical levels while performing better on the novel object recognition task.

Discussion

These preclinical data underscore a potential risk of combining high-fat and high BCAA consumption, and possible benefits from BCAA restriction in AD.

A Review of the Effects of Leucine Metabolite (β-Hydroxy-β-methylbutyrate) Supplementation and Resistance Training on Inflammatory Markers: A New Approach to Oxidative Stress and Cardiovascular Risk Factors

β-hydroxy β-methylbutyrate (HMB) is a bioactive metabolite formed from the breakdown of the branched-chain amino acid, leucine. Given the popularity of HMB supplements among different athletes, specifically, those who participate in regular resistance training, this review was performed to summarize current literature on some aspects of HMB supplementation that have received less attention. Because of the small number of published studies, it has not been possible to conclude the exact effects of HMB on cardiovascular parameters, oxidative stress, and inflammatory markers. Thus, the interpretation of outcomes should be taken cautiously. However, the data presented here suggest that acute HMB supplementation may attenuate the pro-inflammatory response following an intense bout of resistance exercise in athletes. Also, the available findings collectively indicate that chronic HMB consumption with resistance training does not improve cardiovascular risk factors and oxidative stress markers greater than resistance training alone. Taken together, there is clearly a need for further well-designed, long-term studies to support these findings and determine whether HMB supplementation affects the adaptations induced by resistance training associated with the body’s inflammatory condition, antioxidative defense system, and cardiovascular risk factors in humans.

Metabolomics profiling of xenobiotics in elite athletes: relevance to supplement consumption

Background

Supplements are widely used among elite athletes to maintain health and improve performance. Despite multiple studies investigating use of dietary supplements by athletes, a comprehensive profiling of serum supplement metabolites in elite athletes is still lacking. This study aims to analyze the presence of various xenobiotics in serum samples from elite athletes of different sports, focusing on metabolites that potentially originate from nutritional supplements.

Methods

Profiling of xenobiotics in serum samples from 478 elite athletes from different sports (football, athletics, cycling, rugby, swimming, boxing and rowing) was performed using non-targeted metabolomics-based mass spectroscopy combined with ultrahigh-performance liquid chromatography. Multivariate analysis was performed using orthogonal partial least squares discriminant analysis. Differences in metabolic levels among different sport groups were identified by univariate linear models.

Results

Out of the 102 detected xenobiotics, 21 were significantly different among sport groups including metabolites that potentially prolong exercise tolerance (caffeic acid), carry a nootropic effect (2-pyrrolidinone), exert a potent anti-oxidant effect (eugenol, ferulic acid 4 sulfate, thioproline, retinol), or originate from drugs for different types of injuries (ectoine, quinate). Using Gaussian graphical modelling, a metabolic network that links various sport group-associated xenobiotics was constructed to further understand their metabolic pathways.

Conclusions

This pilot data provides evidence that athletes from different sports exhibit a distinct xenobiotic profile that may reflect their drug/supplement use, diet and exposure to various chemicals. Because of limitation in the study design, replication studies are warranted to confirm results in independent data sets, aiming ultimately for better assessment of dietary supplement use by athletes.

Analysis of Nutritional Supplements Consumption by Squash Players

The aim of the present study is to analyse nutritional supplements (NS) consumption by squash players of different levels (international vs. national). A total of 14 international players and 28 national ones answered a NS consumption frequency questionnaire that had been previously validated. A T-Student test was used for independent samples and a χ² test was used in the comparative analysis among athletes of different levels. International level players consume NS in greater proportion vs. national level players (100% vs. 67.9% p = 0.017), with differences in the consumption of bicarbonate of soda, glutamine, branched-chain amino acids, and flaxseed oil (p < 0.05). Even though international level athletes show a greater total number of NS, as well as of the total of NS of each of the categories based on scientific evidence level (sports food, medical supplements, and ergogenic aids of groups A, B, C, and D) in relation to the national level athletes, no statistically significant differences were detected (p > 0.05). With regard to nutritional advice, there are also differences among performance levels (p = 0.003), being personal trainers (28.6%) and dietitians-nutritionists (21.4%) the greatest prescribers when it comes to international-level players, whereas 55.6% of the national-level players do not receive nutritional advice. The pattern of NS consumption, based on evidence level, is unbalanced and its performance could be favored if the dietitian-nutritionist were included as a nutritional advisor for these athletes.

Association between whey protein, regional fat mass, and strength in resistance-trained men: a cross-sectional study

The purpose of this study was to evaluate the association between whey protein supplementation, body composition, and muscle strength in resistance-trained individuals. Forty-nine healthy males, aged 18 to 35 years and were engaged in resistance training for at least 1 year, were assigned into 2 groups according to whey protein intake (whey - n = 26, age: 30.7 ± 7.4 years, body mass: 75.8 ± 9.0 kg; without whey: n = 23, age: 31.0 ± 7.4 years, body mass: 77.9 ± 9.3 kg). Using a cross-sectional design, a morning assessment of body fat mass (FM) (by dual-energy X-ray absorptiometry) and strength (using 1-repetition maximum for bench press and back squat) was performed. Nutritional assessment was performed by 3-day food records. Regarding nutritional habits, differences between total energy intake (kcal) and estimated energy requirements (kcal) were observed. Results, from raw data or controlling for energy intake, estimated energy requirements, or achieved percentage of energy requirements, showed that whey protein supplementation was inversely correlated with whole-body FM (R = -0.367 (p = 0.010); R = -0.317 (p = 0.049); R = -0.380 (p = 0.011); R = -0.321 (p = 0.047), respectively), trunk FM (R = -0.396 (p = 0.005), R = -0.367 (p = 0.022), R = -0.423 (p = 0.004), R = -0.369 (p = 0.021), respectively) and android FM (R = -0.381 (p = 0.007), R = -0.332 (p = 0.039), R = -0.383 (p = 0.010), R = -0.336 (p = 0.036), respectively). No correlations were found between muscle strength outcomes and whey protein supplementation. The present data suggest that whey protein ingestion has a positive association with whole-body and regional (trunk and android) FM.

Increasing effort without noticing: A randomized controlled pilot study about the ergogenic placebo effect in endurance athletes and the role of supplement salience

Purpose

Previous research shows that endurance performance can be enhanced by placebo ergogenic aids. This study investigates the ergogenic placebo response, which we define as an increase in objective and physiological effort without an increase in subjective effort, in competitive cyclists. The primary objective of this study is to explore the role of supplement salience in the ergogenic placebo response, while the secondary aim is to assess whether believing to have taken an inactive placebo supplement attenuates the desired ergogenic effect.

Methods

We employed a double-blind placebo-controlled study design and compared a high salience (pudding) to a low salience (capsules) ergogenic placebo supplement and to a no treatment control group. Thirty-four male athletes (30.0 ± 5.7 years) performed two self-regulated time trials on an isokinetic cycling ergometer, one without intervention serving as a baseline and one with intervention according to group assignment. At both time trials, power output (objective effort), blood lactate (physiological effort) and the rating of perceived exertion (subjective effort) were measured.

Results

Receiving a high salience supplement can increase physiological and objective effort without a proportional rise in subjective effort, suggesting a decoupling of perceived exertion and endurance performance. Low salience and control group both showed no such ergogenic placebo response. Athletes’ belief concerning the true nature of the ergogenic aid (inactive placebo vs. ergogenic supplement) did not influence the ergogenic placebo response.

Conclusion

High salience placebo ergogenic aids can elicit enhanced performance without the athlete noticing (exertion), and deception of athletes seems unnecessary as even believing to have received an inactive placebo supplement maintains the ergogenic placebo response.

PILATES (Physical Activity and Diet Survey): An Italian Self-Administered Questionnaire Evaluating Diet Habits of Gym-Goers. Validation Process

PILATES study aims are to assess the main characteristics related to food habits, diet behaviors, and nutrition knowledge and how and where gym-goers get information on dietary supplementation. We present evidence for the reliability, feasibility, and construct validity of the PILATES questionnaire. Cohen's kappa statistic (k) for dichotomous variables was used to assess the agreement between the two administrations (interrater agreement). The nutrient composition and energy of food were derived from the Food Composition Database for Epidemiological Studies in Italy (Banca Dati di Composizione degli Alimenti per Studi Epidemiologici in Italia - BDA). Because of energy intake, waist circumference and weight are continuous variables; we calculate the agreement between the two interviews using Spearman's rho coefficient (nonparametric measure of rank correlation). An Italian 21-item self-administered questionnaire was designed and pretested on 28 students in food science and human nutrition at the University of Perugia who were enrolled on a voluntary basis. After verifying the feasibility of the questionnaire, pretest evaluation showed a generally high concordance with an 87.32% of agreement and k value = 0.71 ± 0.23. In addition, weight, daily energy intake, and waist circumference confirmed a statistically significant agreement (p <.001, Spearman rho coefficient). PILATES questionnaire is a valid tool to estimate dietary intakes in a fairly simple, cost-effective, and timesaving manner.

IOC consensus statement: dietary supplements and the high-performance athlete

Nutrition usually makes a small but potentially valuable contribution to successful performance in elite athletes, and dietary supplements can make a minor contribution to this nutrition programme. Nonetheless, supplement use is widespread at all levels of sport. Products described as supplements target different issues, including (1) the management of micronutrient deficiencies, (2) supply of convenient forms of energy and macronutrients, and (3) provision of direct benefits to performance or (4) indirect benefits such as supporting intense training regimens. The appropriate use of some supplements can benefit the athlete, but others may harm the athlete's health, performance, and/or livelihood and reputation (if an antidoping rule violation results). A complete nutritional assessment should be undertaken before decisions regarding supplement use are made. Supplements claiming to directly or indirectly enhance performance are typically the largest group of products marketed to athletes, but only a few (including caffeine, creatine, specific buffering agents and nitrate) have good evidence of benefits. However, responses are affected by the scenario of use and may vary widely between individuals because of factors that include genetics, the microbiome and habitual diet. Supplements intended to enhance performance should be thoroughly trialled in training or simulated competition before being used in competition. Inadvertent ingestion of substances prohibited under the antidoping codes that govern elite sport is a known risk of taking some supplements. Protection of the athlete's health and awareness of the potential for harm must be paramount; expert professional opinion and assistance is strongly advised before an athlete embarks on supplement use.

IOC Consensus Statement: Dietary Supplements and the High-Performance Athlete

Nutrition usually makes a small but potentially valuable contribution to successful performance in elite athletes, and dietary supplements can make a minor contribution to this nutrition program. Nonetheless, supplement use is widespread at all levels of sport. Products described as supplements target different issues, including the management of micronutrient deficiencies, supply of convenient forms of energy and macronutrients, and provision of direct benefits to performance or indirect benefits such as supporting intense training regimens. The appropriate use of some supplements can offer benefits to the athlete, but others may be harmful to the athlete's health, performance, and/or livelihood and reputation if an anti-doping rule violation results. A complete nutritional assessment should be undertaken before decisions regarding supplement use are made. Supplements claiming to directly or indirectly enhance performance are typically the largest group of products marketed to athletes, but only a few (including caffeine, creatine, specific buffering agents and nitrate) have good evidence of benefits. However, responses are affected by the scenario of use and may vary widely between individuals because of factors that include genetics, the microbiome, and habitual diet. Supplements intended to enhance performance should be thoroughly trialed in training or simulated competition before implementation in competition. Inadvertent ingestion of substances prohibited under the anti-doping codes that govern elite sport is a known risk of taking some supplements. Protection of the athlete's health and awareness of the potential for harm must be paramount, and expert professional opinion and assistance is strongly advised before embarking on supplement use.

Athletes and Supplements: Prevalence and Perspectives

In elite sport, where opponents are evenly matched, small factors can determine the outcome of sporting contests. Not all athletes know the value of making wise nutrition choices, but anything that might give a competitive edge, including dietary supplements, can seem attractive. Between 40% and 100% of athletes typically use supplements, depending on the type of sport, level of competition, and the definition of supplements. However, unless the athlete has a nutrient deficiency, supplementation may not improve performance and may have a detrimental effect on both performance and health. Dietary supplements are classified as a subcategory of food, so manufacturers are not required to provide evidence of product safety and efficacy, nor obtain approval from regulatory bodies before marketing supplements. This creates the potential for health risks, and serious adverse effects have been reported from the use of some dietary supplements. Athletes who compete in sports under an anti-doping code must also realize that supplement use exposes them to a risk of ingesting banned substances or precursors of prohibited substances. Government systems of regulations do not include specific laboratory testing for banned substances according to the WADA list, so a separate regulatory framework to evaluate supplements for their risk of provoking a failed doping test is needed. In the high-performance culture typical of elite sport, athletes may use supplements regardless of possible risks. A discussion around medical, physiological, cultural, and ethical questions may be warranted to ensure that the athlete has the information needed to make an informed choice.

No association between vitamin C and E supplementation and grip strength over 5 years: the Colaus study

PURPOSE

To assess the cross-sectional and longitudinal association between self-reported vitamin C + E dietary supplementation and markers of grip strength and frailty in community-dwelling Swiss adults.

METHODS

Population-based study including 3277 participants (1722 women) aged 40-80 years at baseline. The associations between vitamin C + E dietary supplementation and grip strength were examined cross-sectionally and after a follow-up of 5.2 years on average.

RESULTS

There were 253 (7.7%) self-reported vitamin C + E supplement users. Female users had significantly lower grip strength than non-users (average ± standard deviation: 24.3 ± 6.1 versus 25.6 ± 6.1 kg, respectively). However, the association disappeared after multivariate adjustment (24.7 ± 0.5 versus 25.6 ± 0.1 kg, for users versus non-users, respectively). No differences were found in men regarding grip strength. No differences were found in the highest quintile of grip strength or prevalence of low grip strengthin in users versus non-users during cross-sectional analysis for both genders. After 5.2 years of follow-up, no associations were found between vitamin C + E supplementation and change in grip strength for raw values (difference between baseline and follow-up: 1.2 ± 5.0 versus 0.4 ± 5.2 kg for female and 0.6 ± 6.5 versus 1.1 ± 6.8 kg for male users and non-users, respectively) or after multivariable adjustment (1.2 ± 0.5 versus 0.4 ± 0.1 kg for female and 0.6 ± 0.8 versus 1.1 ± 0.2 kg for male users and non-users, respectively) when taking baseline vitamin C + E supplementation into account. No association was also found for incidence of low grip strength.

CONCLUSION

In a sample of community-dwelling Swiss adults, vitamin C + E supplementation neither improved grip strength nor prevented low-grip strength over a 5-year period.

Achieving Optimal Post-Exercise Muscle Protein Remodeling in Physically Active Adults through Whole Food Consumption

Dietary protein ingestion is critical to maintaining the quality and quantity of skeletal muscle mass throughout adult life. The performance of acute exercise enhances muscle protein remodeling by stimulating protein synthesis rates for several hours after each bout, which can be optimized by consuming protein during the post-exercise recovery period. To date, the majority of the evidence regarding protein intake to optimize post-exercise muscle protein synthesis rates is limited to isolated protein sources. However, it is more common to ingest whole food sources of protein within a normal eating pattern. Emerging evidence demonstrates a promising role for the ingestion of whole foods as an effective nutritional strategy to support muscle protein remodeling and recovery after exercise. This review aims to evaluate the efficacy of the ingestion of nutrient-rich and protein-dense whole foods to support post-exercise muscle protein remodeling and recovery with pertinence towards physically active people.

Protein Supplement Usage Among Male University Students: Comparisons Between Current and Previous Users

OBJECTIVE

Interest in specialized dietary supplements is leading market growth, and protein supplements are popular for increasing muscle mass among young males. Therefore, this study investigated the attitudes toward and satisfaction with protein supplements to identify detailed consumer behaviors related to the consumption of protein supplements.

METHOD

The study sample includes male university students in their 20s in South Korea. In total, 223 responses were entered for analysis. Questions related to attitudes, satisfaction, and future behavioral intentions were asked using 5-point Likert scales. The responses were divided into two groups, current and previous users, to identify significant differences in terms of attitudes, satisfaction, and future behavioral intentions. A descriptive analysis, analysis of variance (ANOVA), and multiple regression were run.

RESULTS

The majority of respondents prefer the powdered form of supplements in bulk with a price range between 30,000 won and 60,000 won. Online shopping was preferred, while word of mouth and friends/family were considered credible information sources. The most common side effects experienced were problems with digestion and hives, although more than 78% did not experience side effects. In comparison between current and previous users in terms of attitudes and satisfaction, the following areas showed significances. Regarding attitudes, the importance of brand, preference for products from overseas, the search for nutritional facts, and reading carefully all product information were significant, while regarding satisfaction, price, effectiveness, and ease of consumption were significant. All significances showed that current users had more positive attitudes and greater satisfaction. Overall, consumers' satisfaction regarding ease of consumption influenced future behavioral intentions.

CONCLUSIONS

The market for protein supplements has been growing, so measuring consumers' attitudes and satisfaction would help attract potential consumers. In addition, analyzing previous users' opinions on products could guide product development and encourage customers to return for repurchase.

Faster, Stronger, Healthier: Adolescent-Stated Reasons for Dietary Supplementation

OBJECTIVE

Examine the underlying reasons and sources of recommendation for dietary supplement (DS) use among adolescents.

DESIGN

Cross-sectional analysis of children's development in Slovenia in September to October, 2014.

SETTING

Nationally recruited sample.

PARTICIPANTS

Adolescents aged 14-19 years enrolled in 15 high schools (n = 1,463).

VARIABLES MEASURED

Reasons for and sources of recommendation for DS use, sports club membership, sports discipline, and extent of physical activity (PA) were self-reported data.

ANALYSIS

Chi-square test of independence was performed to compare the prevalence of DS use between groups with different extents of PA and nonathletes/athletes, referring to 11 different reasons and 9 different sources of recommendation for DS use.

RESULTS

Use of DS was widespread among adolescents (69%), athletes (76%), and nonathletes (66%). Higher prevalence of supplementation was observed in males, who justified it use for sports performance enhancement and better development and function of muscles. In contrast, females emphasized immune system improvement. Higher extent of PA was associated with a higher prevalence of DS use. This was especially evident in males, who participated in team sports. A high percentage of adolescents (41%) decided on their own to use DS and because of advice from parents or relatives (30%).

CONCLUSIONS AND IMPLICATIONS

Several reasons for the widespread use of DS in adolescents were associated with sports participation. Therefore, educational programs regarding DS use should be targeted primarily to adolescents and their parents who are involved in sports, and especially team sports.

Prohibited Contaminants in Dietary Supplements

CONTEXT

With the increasing use of unregulated dietary supplements, athletes are at continued risk from adverse medical events and inadvertent doping.

EVIDENCE ACQUISITION

A review of Clinical Key, MEDLINE, and PubMed databases from 2012 to 2017 was performed using search terms, including dietary supplement, contamination, doping in athletes, inadvertent doping, and prohibited substances. The references of pertinent articles were reviewed for other relevant sources.

STUDY DESIGN

Clinical review.

LEVEL OF EVIDENCE

Level 3.

RESULTS

Poor manufacturing processes and intentional contamination with many banned substances continue to occur in dietary supplements sold in the United States. Certain sectors, such as weight loss and muscle-building supplements, pose a greater threat because they are more likely to be contaminated.

CONCLUSION

Athletes will continue to be at risk for adverse events and failed doping tests due to contaminated dietary supplements until legislation changes how they are regulated. In the interim, there are several steps that can be taken to mitigate this risk, including improved education of medical staff and athletes and use of third party-certified products.

The Effectiveness of a New School-Based Media Literacy Intervention on Adolescents' Doping Attitudes and Supplements Use

The aim of the study was to evaluate the effectiveness of a media literacy intervention targeting, for the first time, the specific topic of Performance and Appearance Enhancing Substances (PAESs) use in high-school students. Overall, 389 students (52% male) aged between 13 and 19 years (mean = 16.56 year; SD = 1.26) participated to a media literacy intervention (i.e., “intervention group”) while 103 students aged between 14 and 19 year (mean = 16.10 year; SD = 1.38) were considered as the control group (i.e., “control group”). In two separate occasions over the course of six consecutive months, students in both groups filled out a set of questionnaires which included measures of social-cognitive beliefs (i.e., attitudes, subjective norms, intentions) and a self-reported measure of retrospective use of doping (Yes/No) and supplements (Yes/No). Compared to students in the control group (Mean_(time1) = 1.96; SD_(time1) = 0.85; and Mean_(time2) = 2.09; SD_(time2) = 0.94), intervention students on average expressed relatively stronger attitudes against doping use over time (Mean_(time1) = 2.2; SD_(time1) = 0.85; and Mean_(time2) = 2.05; SD_(time2) = 0.82). Students in the latter group also showed a statistically significant decrease in self-reported supplement use (Use_(time1) = 6.7%; Use_(time2) = 3.8%; p = 0.05, McNemar Test). Interestingly, albeit marginally significant, students in the control group showed a relative increment in the self-reported use of supplements over time (Use_(time1) = 4.9%; Use_(time2) = 8.7%; p = 0.22, McNemar Test). Overall, the media literacy intervention investigated in the present study was effective in decreasing adolescent student’s positive attitudes toward doping use and in reducing the use of legal PAES. These findings supported the generalizability and the usefulness of a media literacy approach in the specific field of PAES.

[Nutritional supplements in sports - sense, nonsense or hazard?]

The excessive sale of dietary supplements (DSs) has become a global multi-billion market as more and more people turn to DSs for a healthy lifestyle or for aesthetic reasons. DSs are also increasingly popular among athletes; 50-85% of recreational and 35-100% of competitive athletes report taking DSs, the latter more regularly. Unless pathological deficiencies are detected, the intake of DSs for recreational athletes is not recommended. While it may be advisable for competitive athletes to supplement their diet with certain macronutrients (proteins and carbohydrates), many micronutrients (vitamins, minerals) as well as allegedly performance enhancing DSs may only show minimal impact under specific conditions and for certain sports. However, most products lack proof of their effectiveness. In some cases, DSs may even have negative effects and reduce performance. Furthermore, competitive athletes should be aware of the fact that DSs may lead to positive doping tests, as they bear the risk of being contaminated with banned substances, or components may be banned substances themselves. Every single case of taking DSs should therefore be critically assessed and discussed with experts prior to use. DSs cannot replace a balanced diet and hard practice.

Echinacea Supplementation: Does it Really Improve Aerobic Fitness?

PURPOSE

Echinacea is an herbal supplement used by endurance athletes for its performance boosting properties. It is thought that Echinacea improves the blood's oxygen carrying capacity by increasing production of erythropoietin (EPO), a glycoprotein that regulates red blood cell formation. Subsequently, these changes would lead to an overall improvement in maximal oxygen uptake (VO2max) and running economy (RE), two markers of aerobic fitness. The purpose of this review is to briefly discuss the physiological variables associated with distance running performance and how these variables are influenced by Echinacea supplementation.

METHODS

To determine Echinacea's ergogenic potential, human studies that used Echinacea in conjunction to analyzing the blood's oxygen carrying capacity and/or aerobic fitness were assessed.

RESULTS

Taken together, the majority of the published literature does not support the claim that Echinacea is a beneficial ergogenic aid. With the exception of one study, several independent groups have reported Echinacea supplementation does not increase EPO production, blood markers of oxygen transport, VO2max or RE in healthy untrained or trained subjects.

CONCLUSION

To date, the published literature does not support the use of Echinacea as an ergogenic aid to improve aerobic fitness in healthy untrained or trained subjects.

Control of antioxidant supplementation through interview is not appropriate in oxidative-stress sport studies: Analytical confirmation should be required

OBJECTIVE

Controlling antioxidant supplementation in athletes involved in studies related to oxidative stress and muscle damage is the key to ensure results. The aim of this study was to confirm through high-performance liquid chromatography (HPLC) analysis whether well-trained individuals lied during a personal interview when asked if they were taking supplements with antioxidants, and how this could affect oxidative stress, muscle damage, and antioxidant response.

METHODS

A total of 94 men, well trained in endurance sports, volunteered in this study. They denied taking any antioxidant supplementation at initial interview. After a HPLC analysis, abnormal α-tocopherol concentrations were detected, probably due to a hidden antioxidant supplementation. Participants were classified into two groups: no evidence of antioxidant supplementation (NS group = α-tocopherol values <80 nmol/mL; n = 75) and evidence of antioxidant supplementation (S group = α-tocopherol values >80 nmol/mL; n = 19). Lipid peroxidation, muscle damage, antioxidant enzyme activity, and nonenzymatic antioxidant content were analyzed according to this classification. Statistical comparisons were performed using Student's t test.

RESULTS

The α-tocopherol concentrations were significantly higher in the S group than in the NS group (MD = 725.01 ± 39.01 nmol/mL; P = 0.001). The S group showed a trend toward lower hydroperoxides than the NS group (MD = 1.19 ± 0.72 nmol/mL; P = 0.071). The S group showed significantly lower catalase activity than the NS group (MD = 0.10 ± 0.02-seg-1 mg-1; P < 0.01). Skeletal muscle damage markers did not differ between experimental groups.

CONCLUSIONS

Data from the present study reveal that 20% of participants lied in the exclusion criteria of antioxidant supplementation in a personal interview, as they showed high plasmatic α-tocopherol concentrations after HPLC verification. Catalase activity seems to be affected by high α-tocopherol plasma levels. Therefore, we strongly recommend the HPLC analysis as a necessary tool to verify the antioxidant intake and preserve results in studies linking oxidative stress and sport.

Preparticipation Evaluation of the Young Athlete: What an Orthopaedic Surgeon Needs to Know

The preparticipation evaluation (PPE) is a widely used tool for detecting health conditions that may delay or disqualify athletic participation. The medical interview is the most valuable tool for identifying athletes who may be at increased risk for injury. Physical examination is tailored to identifying cardiac abnormalities or factors that may place an athlete at increased risk for injury. Although practiced in Europe, universal cardiac screening with electrocardiography is not currently recommended in the United States largely due to the high rate of false-positive results. Neuropsychological testing for management of concussion and laboratory testing for sickle cell trait may be indicated in select groups of athletes. Health care providers should view the PPE as a chance for anticipatory guidance and athlete-directed health counseling. Despite widespread acceptance of the PPE, the quality of such examinations varies significantly, which is an area for possible improvement and further research.

Repeated Supramaximal Exercise-Induced Oxidative Stress: Effect of β-Alanine Plus Creatine Supplementation

Background:

Carnosine is a dipeptide formed from the β-alanine and histidine amino acids and found in mainly in the brain and muscle, especially fast twitch muscle. Carnosine and creatine has an antioxidant effect and carnosine accounts for about 10% of the muscle's ability to buffer the H⁺ ions produced by exercise.

Objectives:

The aim of the study was to investigate the effects of beta alanine and/or creatine supplementation on oxidant and antioxidant status during repeated Wingate tests (WTs).

Patients and Methods:

Forty four sedentary males participated in the study. Participants performed three 30s WTs with 2 minutes rest between exercise bouts. After the first exercise session, the subjects were assigned to one of four groups: Placebo, Creatine, Beta-alanine and Beta-alanine plus creatine. Participants ingested twice per day for 22 consecutive days, then four times per day for the following 6 days. After the supplementation period the second exercise session was applied. Blood samples were taken before and immediately after the each exercise session for the analysis of oxidative stress and antioxidant markers.

Results:

Malondialdehyde levels and superoxide dismutase activities were affected by neither supplementation nor exercise. During the pre-supplementation session, protein carbonyl reduced and oxidized glutathione (GSH and GSSG) levels increased immediately after the exercise. However, during the post-supplementation session GSH and GSSG levels increased in beta-alanine and beta-alanine plus creatine groups immediately after the exercise compared to pre-exercise. In addition, during the post-supplementation session total antioxidant capacity increased in beta-alanine group immediately after the exercise.

Conclusions:

Beta-alanine supplementation has limited antioxidant effect during the repeated WTs.

Benefit beliefs about protein supplements: A comparative study of users and non-users

The consumption of protein supplements among leisure time exercisers is growing. The present study aims to identify factors that motivate protein supplement consumption by comparing users' and non-users' underlying benefit beliefs about protein supplement. The study is based on an online survey of 813 Swiss adults (376 users of protein supplements and 437 non-users). Participants answered questions related to their benefit beliefs regarding protein supplement, their protein supplements consumption frequency, their activity level (GPAQ), and their reasons for taking protein supplement. In women, the most commonly cited reasons were to increase muscles (57.3%) and to regulate their weight (48.6%); and in men to increase muscles (83.7%) and to promote regeneration (53.7%). Furthermore, a principal component analysis revealed four benefit belief factors: (a) restore nutrients/avoid weakness; (b) fitness promotion; (c) health/well-being; (d) muscle modulation/competitive performance. The analysis showed that both users and non-users predominantly perceive protein supplements consumption as a strategy to modulate muscle mass, while beliefs in a health and well-being promoting effect was more prevalent among users (M = 3.2, SD = 1.3) than non-users (M = 2.7, SD = 1.3) (p < 0.001). Moreover, health and wellbeing-related beliefs were associated with an increased likelihood of a higher protein supplements intake frequency (OR = 1.5, 95% CI: 1.1-1.9), while physical activity level was not associated with protein supplements intake frequency. In addition, a negative correlation between physical activity level and beliefs in a fitness-promoting effect of protein supplements (r = -0.14, p < 0.001) was observed, indicating that for a subgroup, protein supplements might license lower activity levels. Despite a lack of scientific evidence, consumers of varying activity levels consume protein supplements and believe in its' various positive features. Users should be better informed to prevent misguided health beliefs.

Analgesics use in competitive triathletes: its relationship to doping and on predicting its usage

The two major objectives of this study were (i) to assess variables that predict the use of analgesics in competitive athletes and (ii) to test whether the use of analgesics is associated with the use of doping. A questionnaire primarily addressing the use of analgesics and doping was distributed among 2,997 triathletes. Binary logistic regression analysis was performed to predict the use of analgesics. Moreover, the randomised response technique (RRT) was used to estimate the prevalence of doping in order to assess whether users of analgesics have a higher potential risk for doping than non-users. Statistical power analyses were performed to determine sample size. The bootstrap method was used to assess the statistical significance of the prevalence difference for doping between users and non-users of analgesics. Four variables from a pool of 16 variables were identified that predict the use of analgesics. These were: "version of questionnaire (English)", "gender (female)", "behaviour in case of pain (continue training)", and "hours of training per week (>12 h/week)". The 12-month prevalence estimate for the use of doping substances (overall estimate 13.0%) was significantly higher in athletes that used analgesics (20.4%) than in those athletes who did not use analgesics (12.4%). The results of this study revealed that athletes who use analgesics prior to competition may be especially prone to using doping substances. The predictors of analgesic use found in the study may be of importance to prepare education material and prevention models against the misuse of drugs in athletes.