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1.
Where are all the men? Low energy availability in male cyclists: A review.
Schofield, KL, Thorpe, H, Sims, ST
European journal of sport science. 2021;(11):1567-1578
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Abstract
Most of the low energy availability (LEA) research has been conducted in female populations. The occurrence of LEA in male athletes is not well known, even with an understanding of the components involved in and contributing to LEA. Cycling is a major risk factor for LEA due to inherent sports characteristics: low impact, high energy demands, and a common perception that leanness is a performance advantage. The purpose of this review is to discuss the cycling-specific studies that have documented components of RED-S. The review demonstrates male cyclists (1) experience energy deficits daily, weekly and throughout a season; (2) exhibit lower bone mineral density at the spine compared to the hip, and low bone mineral density correlating with LEA and; (3) demonstrate downregulation of the endocrine system with elevated cortisol, reduced testosterone and insulin-like growth factor 1. The complexity of LEA is further explored by the socio-psychological contribution that may impact eating behaviours, and therefore increase the risk of developing LEA. Future research directions include applying multifaceted research methods to gain a greater understanding of this syndrome and the effect of LEA on male cyclists.
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[Fraud in nutritional supplements for athletes: a narrative review].
Martínez-Sanz, JM, Mata, F, Sala Ripoll, M, Puya Braza, JM, Martínez Segura, A, Sánchez Oliver, AJ, Cortell Tormo, JM
Nutricion hospitalaria. 2021;(4):839-847
Abstract
The use of nutritional supplements (NSs) is a widespread practice in both professional and amateur athletes. Their choice must be based on criteria of safety, legality, and effectiveness. There are several risks that some of these products can trigger, this being a reason for fraud to the consumer. By way of example, the presence of a legal substance in doses higher than its recommendation may cause unwanted side effects; on the other hand, its presence in quantities lower than necessary (effective threshold) may not have the effect expected or announced by the product. Therefore, the objective of this review was to describe the existence of fraud in relation to nutritional labeling and/or to the content of NSs intended for athletes. A narrative review was conducted through PubMed in which 16 studies met the inclusion criteria. The results show that nutritional labeling differs from the actual amounts of ingredients. This type of fraud has been found in protein powder supplements, pre-workout mixtures, creatine, and beverages containing vitamins and minerals, among others. Fraud due to errors in the labeling by omission of substances present in the product or by errors in the analysis or declaration of quantities, is high. This lack of transparency in the actual composition of labels can contribute to sports performance and/or health problems in the athlete. Therefore, an improvement of the legislation on NS is necessary to ensure their safety, effectiveness, and legality.
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Dietary and Ergogenic Supplementation to Improve Elite Soccer Players' Performance.
Fernandes, H
Annals of nutrition & metabolism. 2021;(4):197-203
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Abstract
BACKGROUND Soccer is an extremely competitive sport, where the most match important moments can be defined in detail. Use of ergogenic supplements can be crucial to improve the performance of a high-performance athlete. Therefore, knowing which ergogenic supplements are important for soccer players can be an interesting strategy to maintain high level in this sport until final and decisive moments of the match. In addition, other supplements, such as dietary supplements, have been studied and increasingly referenced in the scientific literature. But, what if ergogenic supplements were combined with dietary supplements? This review brings some recommendations to improve performance of soccer athletes on the field through dietary and/or ergogenic supplements that can be used simultaneously. SUMMARY Soccer is a competitive sport, where the match important moments can be defined in detail. Thus, use of ergogenic supplements covered in this review can improve performance of elite soccer players maintaining high level in the match until final moments, such as creatine 3-5 g day-1, caffeine 3-6 mg kg-1 BW around 60 min before the match, sodium bicarbonate 0.1-0.4 g kg-1 BW starting from 30 to 180 min before the match, β-alanine 3.2 and 6.4 g day-1 provided in the sustained-release tablets divided into 4 times a day, and nitrate-rich beetroot juice 60 g in 200 mL of water (6 mmol of NO3- L) around 120 min before match or training, including a combination possible with taurine 50 mg kg-1 BW day-1, citrulline 1.2-3.4 g day-1, and arginine 1.2-6 g day-1. Key Messages: Soccer athletes can combine ergogenic and dietary supplements to improve their performance on the field. The ergogenic and dietary supplements used in a scientifically recommended dose did not demonstrate relevant side effects. The use of various evidence-based supplements can add up to further improvement in the performance of the elite soccer players.
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Effects of Co-Ingestion of β-Hydroxy-β-Methylbutyrate and L-Arginine α-Ketoglutarate on Jump Performance in Young Track and Field Athletes.
Kaczka, P, Kubicka, K, Batra, A, Maciejczyk, M, Kopera, E, Bira, J, Zając, T
Nutrients. 2021;(4)
Abstract
UNLABELLED The aim of the study was to determine the effect of simultaneous supplementation of β-hydroxy-β-methylbutyrate and L-Arginine α-ketoglutarate on lower limb power and muscle damage in medium distance runners aged 15.3 (±0.9) years old. METHODS The study group consisted of 40 volunteers aged 14-17 years practicing medium distance running for at least two years. The study lasted 12 days and followed a randomized, double-blind, placebo-controlled, parallel design. All subjects attended a familiarization session on day 0 before the test. The subjects were randomly divided into two groups: supplements and placebo group. The same training cycle protocol was used in both groups during the 12-day training period. Morning warm-up involved 10 min jogging at 60-75% of maximal heart rate and countermovement jump height measurement. Main training units were carried out for both groups with the same volume. Training load assessment (the daily session Rating of Perceived Exertion (s-RPE) method) method takes into consideration the intensity and the duration of the training session to calculate the "training load" (TL). RESULTS At the end of the training cycle, a significant (p = 0.002) decrease in the countermovement jump (CMJ) height was found in the placebo group when compared to the baseline. In the supplement group, there was no decrease in the countermovement jump height. Creatine kinase and lactate dehydrogenase concentration increased during the training days similarly in both groups and decreased on rest days. There were no differences between groups in enzymes concentration. The research results indicate that the supplement combination used in the supplements group prevented a reduction in the CMJ values. In contrast to the supplements group, in the placebo group, the CMJ changes were statistically significant: a noticeable (p = 0.002) decrease in CMJ was noted between the baseline measurement and the 6th measurement. The well-being of the subjects from both groups changed significantly during the training period, and the intergroup differences in the mood level were similar and not statistically significant. CONCLUSIONS The results of this study indicate that the daily co-supplementation with calcium salt of β-hydroxy-β-methylbutyrate (7.5 g) and L-Arginine α-ketoglutarate (10 g) during training might help to prevent decline in jump performance. No influence on muscle damage markers or mood was shown.
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Profiles for identifying problematic dietary habits in a sample of recreational Spanish cyclists and triathletes.
Muros, JJ, Knox, E, Hinojosa-Nogueira, D, Rufián-Henares, JÁ, Zabala, M
Scientific reports. 2021;(1):15193
Abstract
There is a lack of sufficient information on the dietary intake and nutritional supplementation of recreational endurance athletes throughout the year. The present observational study sought to assess the dietary intake and nutritional supplementation habits of recreational cyclists and triathletes from Spain. 4,037 cyclists and triathletes completed self-report measures. Nutritional profiles were developed and differences were examined according to sporting discipline and gender. Differences between groups were compared using the Mann-Whitney U or chi-squared test. Next, micro- and macro-nutrients were grouped according to whether or not guideline intake amounts were met. The clustering of dietary habits was then examined via K-means cluster analysis. Triathletes took more supplements than cyclists (X2 = 36.489; p value = .000) and females took more supplements than males (X2 = 5.920; p value = .017). Females and triathletes reported greater protein and CHO consumption than males and cyclists, respectively. Triathletes also reported a higher consumption of total fat, MUFA, PUFA, EPA, DHA and fibre. Females and triathletes tended to consume more vitamins and minerals than males and cyclists, respectively. Two main dietary habit clusters emerged which may be used to inform nutritional interventions targeting recreational athletes not meeting nutritional requirements. There is an imbalance in the main nutrients making up the diet of recreational Spanish athletes, characterised by insufficient CHO and excessive protein.
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The behavioral, psychological, and social impacts of team sports: a systematic review and meta-analysis.
Zuckerman, SL, Tang, AR, Richard, KE, Grisham, CJ, Kuhn, AW, Bonfield, CM, Yengo-Kahn, AM
The Physician and sportsmedicine. 2021;(3):246-261
Abstract
Objectives: To assess the association between team sport participation and behavioral, psychological, and social health outcomes in young athletes.Methods: A systematic review and meta-analysis were undertaken to identify studies published between 01/01/1950-05/01/2020 investigating the association between team sport participation and health outcomes in young athletes (<25 years). Included studies compared team sport participants to controls or themselves, assessed health outcomes, and had a sample size >50. Prospective and retrospective studies were included; non-primary literature was excluded. Health outcomes were categorized as: 1) behavioral, 2) psychological, or 3) social. Data were extracted to form 2 × 2 tables for each study to calculate odds ratios (OR) and 95% confidence intervals (CI).Results: Of 371 queried articles, 34 studies from 10 countries across 4 continents were included, with 9 reporting homogenous outcomes for meta-analysis.Behavioral: Fifteen studies evaluated behavioral health outcomes of alcohol and/or drug use, fitness, and diet. Quantitatively, team sport participation was found to decrease rates of cigarette/tobacco use across 5 studies (OR 0.72, 95% CI 0.69-0.76) and alcohol/drug use across 7 studies (OR 0.73, 95% CI 0.69-0.77). Qualitatively, 12/15 (80%) of studies confirmed improved behavioral health outcomes with team sport participation.Psychological: Nineteen studies evaluated psychological health outcomes including anorexia, anxiety, depression, self-esteem, and suicidal ideation. Quantitatively, team sport participation was associated with decreased depression/anxiety rates across 5 studies (OR 0.59, 95%CI 0.54-0.64). Qualitatively, 14/19 (74%) of studies confirmed improved psychological health.Social: Ten studies evaluated social health outcomes including academic performance, commitment, psychosocial health, social behavior/identity, and delinquency/high-risk activity. Qualitatively, 7/10 (70%) of studies confirmed improved social health outcomes with team sport participation.Conclusion: Team sport participation was associated with decreased odds of smoking/tobacco use, alcohol/drug use, and depression/anxiety. Though few studies mentioned potential negative effects of team sport participation, the majority reported improved behavioral, psychological, and social health outcomes in youth athletes worldwide.
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Caffeine and Cognitive Functions in Sports: A Systematic Review and Meta-Analysis.
Lorenzo Calvo, J, Fei, X, Domínguez, R, Pareja-Galeano, H
Nutrients. 2021;(3)
Abstract
Cognitive functions are essential in any form of exercise. Recently, interest has mounted in addressing the relationship between caffeine intake and cognitive performance during sports practice. This review examines this relationship through a structured search of the databases Medline/PubMed and Web of Science for relevant articles published in English from August 1999 to March 2020. The study followed PRISMA guidelines. Inclusion criteria were defined according to the PICOS model. The identified records reported on randomized cross-over studies in which caffeine intake (as drinks, capsules, energy bars, or gum) was compared to an identical placebo situation. There were no filters on participants' training level, gender, or age. For the systematic review, 13 studies examining the impacts of caffeine on objective measures of cognitive performance or self-reported cognitive performance were selected. Five of these studies were also subjected to meta-analysis. After pooling data in the meta-analysis, the significant impacts of caffeine only emerged on attention, accuracy, and speed. The results of the 13 studies, nevertheless, suggest that the intake of a low/moderate dose of caffeine before and/or during exercise can improve self-reported energy, mood, and cognitive functions, such as attention; it may also improve simple reaction time, choice reaction time, memory, or fatigue, however, this may depend on the research protocols.
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Palatable Flavoured Fluids without Carbohydrates and Electrolytes Do Not Enhance Voluntary Fluid Consumption in Male Collegiate Basketball Players in the Heat.
Taim, BC, Suppiah, HT, Wee, J, Lee, M, Lee, JKW, Chia, M
Nutrients. 2021;(12)
Abstract
Using palatable fluids to enhance drinking in athletes who display insufficient compensatory hydration behaviour may mitigate the risks of hypohydration and performance deficits. However, it is unclear whether flavour can independently enhance fluid consumption. This study examined the effects of a colourless, artificially sweetened flavoured water (FW), without carbohydrates and with negligible amounts of sodium, compared to plain water (W) on fluid consumption in male collegiate basketball players in a practical game setting. Eighteen male basketball players (age 23.1 ± 1.3 years) played a 3v3 basketball small-sided game. The players were randomly assigned to consume either FW or W. Pre-game urine-specific gravity, fluid consumption, body mass, and hedonic taste perceptions were assessed. Basketball performance was analysed through notational analysis. Ratings of perceived exertion and thirst were recorded at pre-, post-game, and at each rest period. Heart rate was recorded throughout the gameplay. Despite significantly higher hedonic ratings for FW than W (6.78 ± 0.83 vs. 5.56 ± 1.33, p = 0.033, d = 1.36), there were no significant differences in fluid consumption (1083 ± 32 mL vs. 1421 ± 403 mL, p = 0.068, d = 0.92). Our result highlighted that using palatable fluids as a strategy to increase fluid consumption during high-intensity gameplay in the heat may not be effective if used without carbohydrates and electrolytes. Practitioners could consider both fluid palatability and composition in establishing a hydration plan for athletes.
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Nutrition Knowledge of Collegiate Athletes in the United States and the Impact of Sports Dietitians on Related Outcomes: A Narrative Review.
Riviere, AJ, Leach, R, Mann, H, Robinson, S, Burnett, DO, Babu, JR, Frugé, AD
Nutrients. 2021;(6)
Abstract
In the last decade, the number of full-time registered dietitians (RDs) serving intercollegiate athletes in the United States has more than quadrupled. However, many student athletes may be at increased risk of nutrition-related problems that impact physical and academic performance, which include inadequate macronutrients, inadequate micronutrients, and excessive macronutrients. This narrative review reports the current literature to date on nutrition-related knowledge in collegiate athletes and the impact of sports RDs on student athletes' nutrition knowledge and behaviors. To date, only observational and quasi-experimental studies have been published with regard to changes in nutrition knowledge and behaviors in NCAA athletes. While these studies report benefits of the RD as a member of the interdisciplinary student athlete support team, more well-designed randomized control trials are warranted to determine benefits related to health outcomes and sport-specific performance outcomes.
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Diet Quality of Elite Australian Athletes Evaluated Using the Athlete Diet Index.
Capling, L, Tam, R, Beck, KL, Slater, GJ, Flood, VM, O'Connor, HT, Gifford, JA
Nutrients. 2020;(1)
Abstract
While athletes' nutrient intakes have been widely reported, few studies have assessed the diet quality of athletes. This is the first study to evaluate the diet quality of athletes using the purpose-built Athlete Diet Index (ADI). A convenience sample of 165 elite athletes from Australian sporting institutions completed the ADI online, with subsequent automated results provided to their respective accredited sports dietitians (ASDs). At the completion of athlete participation, ASDs (n = 12) responded to a range of survey items using a Likert scale (i.e., 1 = strongly agree to 5 = strongly disagree) to determine the suitability of the ADI in practice. Differences in ADI scores for demographics and sport-specific variables were investigated using independent t-tests, analysis of variance (ANOVA) and Bonferroni multiple comparisons. Spearman's rank correlation was used to assess the association between total scores and demographics. The mean total ADI score was 91.4 ± 12.2 (range 53-117, out of a possible 125). While there was no difference in total scores based on demographics or sport-specific variables; team sport athletes scored higher than individual sport athletes (92.7 vs. 88.5, P < 0.05). Athletes training fewer hours (i.e., 0-11 h/week) scored higher on Dietary Habits sub-scores compared with athletes training more hours (> 12 h/week; P < 0.05), suggesting that athletes who train longer may be at risk of a compromised dietary pattern or less than optimal nutrition practices that support training. Most (75%) ASDs surveyed strongly agreed with the perceived utility of the ADI for screening athletes and identifying areas for nutrition support, confirming its suitability for use in practice.