Methodologies for Investigating Performance Changes With Supplement Use

Individual Responses to Repeated Dosing with Anthocyanin-Rich New Zealand Blackcurrant Extract During High-Intensity Intermittent Treadmill Running in Active Males

Intake of New Zealand blackcurrant (NZBC) extract for 7 days has been shown to improve high-intensity intermittent running (HIIR) performance.

OBJECTIVES

We examined the repeat response of NZBC extract on HIIR performance.

METHODS

Sixteen active males (age: 23 ± 3 yrs, height: 179 ± 5 cm, mass: 79 ± 11 kg, V˙O2max: 55.3 ± 5 mL∙kg-1∙min-1, velocity at V˙O2max: 17.2 ± 0.8 km∙h-1, mean ± SD) participated. Familiarized subjects completed the HIIR test at individualized exercise intensities with stages consisting of six 19 s high-intensity running bouts interspersed by 15 s of low-intensity running and 1 min of inter-stage rest. The test was repeated at increasing speeds until exhaustion, under four conditions; two with a daily dose of 600 mg of NZBC extract (CurraNZ™, providing 210 mg anthocyanins) and two with a placebo, each over 7 days. The study used a double-blind, randomized, cross-over design with a wash-out period of at least 14 days.

RESULTS

For the cohort, there were no differences between the placebo and NZBC conditions for mean heart rate (p = 0.071), mean oxygen uptake (p = 0.713), and mean lactate (p = 0.121) at exhaustion for the HIIR. The NZBC extract increased the mean total running distance and mean high-intensity running distance by 7.9% and 8.0% compared to the placebo. With NZBC extract, 8 of the 16 participants (50%) enhanced in both trials beyond the smallest worthwhile change for total running distance (≥173 m) and high-intensity running distance (≥111 m). For repeated responders, total running distance and high-intensity running distance was increased by 16.7% (95% CI [11.0, 22.4%] and 16.6% (95% CI [11.0, 22.2%]. Three participants had enhanced running performance in one trial beyond the SWC, and five participants were considered non-responders.

CONCLUSIONS

This is the first study on the repeated response by an anthocyanin-rich supplement on high-intensity running performance. New Zealand blackcurrant extract can substantially enhance intermittent high-intensity running performance in consistent responders. Future work should examine dosing strategies of New Zealand blackcurrant, and whether a repeated response rate exceeding 50% can be attained. These findings suggest that NZBC extract could be beneficial for athletes participating in high-intensity team sports.

Use of Sport Supplements and Doping Substances by Athletes: Prevalence and Relationships

Background: The use of sport supplements may represent a risk factor for the use of doping in sports. To explore this putative risk, the current study examined the frequency of sport supplement use and associations between the use of sport supplements and the use of doping substances and methods in athletes. Methods: The participants (n = 345; 56% male, 22 ± 5 years, 18-43 years) completed measures of sport supplement use, sport supplement beliefs, doping likelihood, and doping use. Based on the Australian Institute of Sport's "Sports Supplement Framework", the participants were asked whether they used 23 sport supplements from four categories (sport foods, medical supplements, performance supplements, other). They were also asked whether they used six classes of doping substances and methods (alphabodies, stimulants, steroids, erythropoietin, growth hormone, blood doping). Results: Sport supplements were used by 96% of the athletes, whereas doping substances were used by 4% of the athletes. Moreover, athletes who used more sport supplements also used more doping substances. The use of sport supplements was related to the use of doping substances both directly and indirectly via sport supplement beliefs and doping likelihood. Conclusions: Consumption of sport supplements is common, whereas doping is rare, and, moreover, the belief that sport supplements help optimize performance in competitive sport confers an increased risk for doping.

Effects of a Dietary Microalgae (Arthrospira platensis) Supplement on Stress, Well-Being, and Performance in Water Polo Players: A Clinical Case Series

BACKGROUND

A common tactic used by athletes to improve performance, lessen tiredness, and hasten recovery is dietary supplementation. We aimed to assess the role of a microalgae dietary liquid supplement additivated with Copper 22.5% NRV in water polo players' performance.

METHODS

Twenty male water polo players were split into two groups: ten (spirulina group) took a twice-daily nutritional supplement containing 15 mL of spirulina liquid extract (titrated in Phycocyanin 1 mg/mL) and additivated with Copper 22.5% NRV for eight weeks, and ten (the placebo group) did not take the supplement. Subjective evaluations were finished using the Athlete's Subjective Performance Scale (ASPS). Levels of the biomarker creatine phosphokinase (CPK) were also assessed.

RESULTS

The spirulina group's mean total ASPS score increased significantly from baseline to follow-up and was significantly better than that of the placebo group (p < 0.001). Conversely, ASPS ratings in the placebo group slightly decreased. A positive correlation between spirulina supplementation and less severe ASPS was found using correlation matrix analysis. However, there was a slight difference in CPK levels from the baseline to the follow-up in the spirulina group.

CONCLUSIONS

A dietary supplement comprising spirulina and copper may help water polo players' subjective performance measurements by lowering muscular tension. Larger, randomized controlled trials are yet required.

Carbohydrate Oral Rinsing, Cycling Performance and Individual Complex Carbohydrate Taste Sensitivity

The aim of this pilot study was to determine the effect of individual complex carbohydrate taste sensitivity on cycling performance with complex carbohydrate oral rinsing. Ten male participants completed five cycling time trials in a fasted state with a seven-day washout period between each trial. Participants completed a fixed amount of work (738.45 ± 150.74 kJ) as fast as possible on a cycle ergometer while rinsing with an oral rinse for 10 s every 12.5% of the trial. An oral rinse (maltodextrin, oligofructose, glucose, sucralose or water control) was given per visit in a randomised, crossover, blinded design. Afterwards, participants had their taste assessed with three stimuli, complex carbohydrate (maltodextrin), sweet (glucose) and sour (citric acid), using taste assessment protocol to determine individual taste sensitivity status. Participants were subsequently grouped according to their complex carbohydrate taste sensitivity and complex carbohydrate taste intensity. There were no significant effects of the oral rinses on cycling performance time (p = 0.173). Participants who did not have improvements in exercise performance with the maltodextrin rinse experienced a stronger taste intensity with complex carbohydrate stimuli at baseline (p = 0.047) and overall (p = 0.047) than those who did have improvements in performance. Overall, a carbohydrate oral rinse was ineffective in significantly improving cycling performance in comparison with a water control. However, when participants were grouped according to complex carbohydrate taste intensity, differences in exercise performance suggest that individual sensitivity status to complex carbohydrates could impact the efficacy of a carbohydrate-based oral rinse.

Food for thought: Physiological considerations for nutritional ergogenic efficacy

Top-class athletes have optimized their athletic performance largely through adequate training, nutrition, recovery, and sleep. A key component of sports nutrition is the utilization of nutritional ergogenic aids, which may provide a small but significant increase in athletic performance. Over the last decade, there has been an exponential increase in the consumption of nutritional ergogenic aids, where over 80% of young athletes report using at least one nutritional ergogenic aid for training and/or competition. Accordingly, due to their extensive use, there is a growing need for strong scientific investigations validating or invalidating the efficacy of novel nutritional ergogenic aids. Notably, an overview of the physiological considerations that play key roles in determining ergogenic efficacy is currently lacking. Therefore, in this brief review, we discuss important physiological considerations that contribute to ergogenic efficacy for nutritional ergogenic aids that are orally ingested including (1) the impact of first pass metabolism, (2) rises in systemic concentrations, and (3) interactions with the target tissue. In addition, we explore mouth rinsing as an alternate route of ergogenic efficacy that bypasses the physiological hurdles of first pass metabolism via direct stimulation of the central nervous system. Moreover, we provide real-world examples and discuss several practical factors that can alter the efficacy of nutritional ergogenic aids including human variability, dosing protocols, training status, sex differences, and the placebo effect. Taking these physiological considerations into account will strengthen the quality and impact of the literature regarding the efficacy of potential ergogenic aids for top-class athletes.

Analysis of the Consumption of Sports Supplements in Open Water Swimmers According to the Competitive Level

BACKGROUND

Sports supplements (SS) are widely consumed by many types of athletes to improve their performance. These SS are classified according to their level of scientific evidence, by the ABCD system from the Australian Institute of Sport (AIS). In open water swimming, their use may be necessary due to the physiological challenges posed by this sport discipline. However, there is currently little literature on the use of SS in open water swimmers. The aim of this work is to analyze the pattern of consumption of SS by open water swimmers, by studying the differences according to the competitive level (regional vs. national).

METHODS

Descriptive and cross-sectional study on the consumption and use of SS by federated open water swimmers in Spain in the 2019/2020 and 2020/2021 seasons. The data were collected through a validated questionnaire.

RESULTS

79.5% of the participants consumed SS, with significant differences according to their level, being higher in athletes at the national level. The most-consumed SS by the swimmers studied were sports drinks, energy bars, caffeine, vitamin C, and vitamin D.

CONCLUSIONS

It was observed that the consumption of SS in open water swimmers was high, and of the five most-consumed SS, four of them belonged to the category of greatest scientific evidence.

Coenzyme Q10 Supplementation and Its Impact on Exercise and Sport Performance in Humans: A Recovery or a Performance-Enhancing Molecule?

Evidence exists to suggest that ROS induce muscular injury with a subsequent decrease in physical performance. Supplementation with certain antioxidants is important for physically active individuals to hasten recovery from fatigue and to prevent exercise damage. The use of nutritional supplements associated with exercise, with the aim of improving health, optimizing training or improving sports performance, is a scientific concern that not only drives many research projects but also generates great expectations in the field of their application in pathology. Since its discovery in the 1970s, coenzyme Q10 (CoQ10) has been one of the most controversial molecules. The interest in determining its true value as a bioenergetic supplement in muscle contraction, antioxidant or in the inflammatory process as a muscle protector in relation to exercise has been studied at different population levels of age, level of physical fitness or sporting aptitude, using different methodologies of effort and with the contribution of data corresponding to very diverse variables. Overall, in the papers reviewed, although the data are inconclusive, they suggest that CoQ10 supplementation may be an interesting molecule in health or disease in individuals without a pathological deficiency and when used for optimising exercise performance. Considering the results observed in the literature, and as a conclusion of this systematic review, we could say that it is an interesting molecule in sports performance. However, clear approaches should be considered when conducting future research.

Ergo-Nutritional Intervention in Basketball: A Systematic Review

Using nutritional supplements is a widespread strategy among basketball players to ensure the appropriate provision of energy and nutrients to avoid certain complaints. Particularly in basketball, there is no consensus on the type, quantity or form of use in which these supplements should be administered. Therefore, the main aim of this systematic review is to highlight the ergo-nutritional aids that may be effective in basketball. A structured search was carried out following the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA®) guidelines in the Medline/PubMed and Web of Science, Cochrane Library, and Scopus databases until 31 December 2021; no year restriction was applied to the search strategy. There were no filters applied to the basketball players' level, gender, race, or age to increase the power of the analysis. The results of this systematic review have shown that the effective dose of caffeine to enhance anaerobic performance and the feeling of vigorousness and energy ranges from 3 to 6 mg·kg-1, showing more positive effects when is supplemented 60-75 min before exercise in the morning and in test-based task. On the other hand, vitamin E (ranging from 200 to 268 mg), vitamin D (10,000 IU) and EPA (2 g) may have a potential role in recovery and wellness. The primary limitation of this study is the scarcity of studies related to nutritional supplementation in basketball players. However, a major strength is that this is the first systematic review describing what ergo-nutritional aids may be specifically helpful for basketball. Despite the need for future studies, certain nutritional supplements may have promising advantages for basketball (long-term supplementation of nitrates for recovery), whereas others (β-alanine, sodium bicarbonate, and acute nitrate supplementation) might theoretically be regarded as not interesting for basketball, or even not recommended by the World Anti-Doping Agency (WADA) as bovine colostrum.

“Food First but Not Always Food Only”: Recommendations for Using Dietary Supplements in Sport

The term “food first” has been widely accepted as the preferred strategy within sport nutrition, although there is no agreed definition of this and often limited consideration of the implications. We propose that food first should mean “where practically possible, nutrient provision should come from whole foods and drinks rather than from isolated food components or dietary supplements.” There are many reasons to commend a food first strategy, including the risk of supplement contamination resulting in anti-doping violations. However, a few supplements can enhance health and/or performance, and therefore a food only approach could be inappropriate. We propose six reasons why a food only approach may not always be optimal for athletes: (a) some nutrients are difficult to obtain in sufficient quantities in the diet, or may require excessive energy intake and/or consumption of other nutrients; (b) some nutrients are abundant only in foods athletes do not eat/like; (c) the nutrient content of some foods with established ergogenic benefits is highly variable; (d) concentrated doses of some nutrients are required to correct deficiencies and/or promote immune tolerance; (e) some foods may be difficult to consume immediately before, during or immediately after exercise; and (f) tested supplements could help where there are concerns about food hygiene or contamination. In these situations, it is acceptable for the athlete to consider sports supplements providing that a comprehensive risk minimization strategy is implemented. As a consequence, it is important to stress that the correct terminology should be “food first but not always food only.”

Exogenous Ketone Supplements in Athletic Contexts: Past, Present, and Future

The ketone bodies acetoacetate (AcAc) and β-hydroxybutyrate (βHB) have pleiotropic effects in multiple organs including brain, heart, and skeletal muscle by serving as an alternative substrate for energy provision, and by modulating inflammation, oxidative stress, catabolic processes, and gene expression. Of particular relevance to athletes are the metabolic actions of ketone bodies to alter substrate utilisation through attenuating glucose utilisation in peripheral tissues, anti-lipolytic effects on adipose tissue, and attenuation of proteolysis in skeletal muscle. There has been long-standing interest in the development of ingestible forms of ketone bodies that has recently resulted in the commercial availability of exogenous ketone supplements (EKS). These supplements in the form of ketone salts and ketone esters, in addition to ketogenic compounds such as 1,3-butanediol and medium chain triglycerides, facilitate an acute transient increase in circulating AcAc and βHB concentrations, which has been termed 'acute nutritional ketosis' or 'intermittent exogenous ketosis'. Some studies have suggested beneficial effects of EKS to endurance performance, recovery, and overreaching, although many studies have failed to observe benefits of acute nutritional ketosis on performance or recovery. The present review explores the rationale and historical development of EKS, the mechanistic basis for their proposed effects, both positive and negative, and evidence to date for their effects on exercise performance and recovery outcomes before concluding with a discussion of methodological considerations and future directions in this field.

Nutritional approaches to counter performance constraints in high-level sports competition

New Findings

What is the topic of this review?

The nutritional strategies that athletes use during competition events to optimize performance and the reasons they use them.

What advances does it highlight?

A range of nutritional strategies can be used by competitive athletes, alone or in combination, to address various event‐specific factors that constrain event performance. Evidence for such practices is constantly evolving but must be combined with understanding of the complexities of real‐life sport for optimal implementation.

Abstract

High‐performance athletes share a common goal despite the unique nature of their sport: to pace or manage their performance to achieve the highest sustainable outputs over the duration of the event. Periodic or sustained decline in the optimal performance of event tasks, involves an interplay between central and peripheral phenomena that can often be reduced or delayed in onset by nutritional strategies. Contemporary nutrition practices undertaken before, during or between events include strategies to ensure the availability of limited muscle fuel stores. This includes creatine supplementation to increase muscle phosphocreatine content and consideration of the type, amount and timing of dietary carbohydrate intake to optimize muscle and liver glycogen stores or to provide additional exogenous substrate. Although there is interest in ketogenic low‐carbohydrate high‐fat diets and exogenous ketone supplements to provide alternative fuels to spare muscle carbohydrate use, present evidence suggests a limited utility of these strategies. Mouth sensing of a range of food tastants (e.g., carbohydrate, quinine, menthol, caffeine, fluid, acetic acid) may provide a central nervous system derived boost to sports performance. Finally, despite decades of research on hypohydration and exercise capacity, there is still contention around their effect on sports performance and the best guidance around hydration for sporting events. A unifying model proposes that some scenarios require personalized fluid plans while others might be managed by an ad hoc approach (ad libitum or thirst‐driven drinking) to fluid intake.

Four Days of Blueberry Powder Supplementation Lowers the Blood Lactate Response to Running But Has No Effect on Time-Trial Performance

Blueberries are abundant with anthocyanins possessing antioxidant and anti-inflammatory properties. As these properties combat fatigue and promote recovery, blueberry supplementation may enhance performance and recovery. Thus, the objectives were to examine the effects of two blueberry supplementation protocols on running performance, physiological responses, and short-term recovery. Using a randomized, double-blind, placebo (PLA)-controlled crossover design, 14 runners completed an 8-km time trial (TT) after supplementation with 4 days of blueberries (4DAY), 4 days of a PLA, or 2 days of placebo followed by 2 days of blueberries (2DAY). Heart rate and ratings of perceived exertion were monitored during the TT. Blood lactate, vertical jump, reactive strength index, and salivary markers were assessed before and after. No significant differences were observed for time to complete the TT (PLA: 3,010 ± 459 s; 2DAY: 3,014 ± 488 s; 4DAY: 3,011 ± 423 s), heart rate, ratings of perceived exertion, or any of the salivary markers. An interaction effect (p = .027) was observed for blood lactate, with lower post-TT concentrations in 4DAY (5.4 ± 2.0 mmol/L) than PLA (6.6 ± 2.5 mmol/L; p = .038) and 2DAY (7.4 ± 3.4 mmol/L; p = .034). Post-TT decreases in vertical jump height were not different, whereas the decline in reactive strength index was less following 4DAY (-6.1% ± 13.5%) than the other conditions (PLA: -12.6% ± 10.1%; 2DAY: -11.6% ± 11.5%; p = .038). Two days of supplementation did not influence performance or physiological stress. Although 4 days of supplementation did not alter performance, it blunted the increase in blood lactate, perhaps reflecting altered lactate production and/or clearance, and offset the decrease in dynamic muscle function post-TT, as indicated by the reactive strength index differences.

Individual Participant Data Meta-Analysis Provides No Evidence of Intervention Response Variation in Individuals Supplementing With Beta-Alanine

Currently, little is known about the extent of interindividual variability in response to beta-alanine (BA) supplementation, nor what proportion of said variability can be attributed to external factors or to the intervention itself (intervention response). To investigate this, individual participant data on the effect of BA supplementation on a high-intensity cycling capacity test (CCT110%) were meta-analyzed. Changes in time to exhaustion (TTE) and muscle carnosine were the primary and secondary outcomes. Multilevel distributional Bayesian models were used to estimate the mean and SD of BA and placebo group change scores. The relative sizes of group SDs were used to infer whether observed variation in change scores were due to intervention or non-intervention-related effects. Six eligible studies were identified, and individual data were obtained from four of these. Analyses showed a group effect of BA supplementation on TTE (7.7, 95% credible interval [CrI] [1.3, 14.3] s) and muscle carnosine (18.1, 95% CrI [14.5, 21.9] mmol/kg DM). A large intervention response variation was identified for muscle carnosine (σIR = 5.8, 95% CrI [4.2, 7.4] mmol/kg DM) while equivalent change score SDs were shown for TTE in both the placebo (16.1, 95% CrI [13.0, 21.3] s) and BA (15.9, 95% CrI [13.0, 20.0] s) conditions, with the probability that SD was greater in placebo being 0.64. In conclusion, the similarity in observed change score SDs between groups for TTE indicates the source of variation is common to both groups, and therefore unrelated to the supplement itself, likely originating instead from external factors such as nutritional intake, sleep patterns, or training status.

The New Challenge of Sports Nutrition: Accepting Insect Food as Dietary Supplements in Professional Athletes

BACKGROUND

The dietary supplements market is growing, and their use is increasing among professional athletes. Recently, several new protein supplements have been placed in the marketplace, including energy bars enriched with insect flour. Edible insects, which are rich in protein content, have been promoted as the food of the future and athletes could be a reference sample for their continued emphasis on higher protein demand. The present study investigated the potential motivations to accept an energy protein bar with cricket flour, among a group of selected Italian professional athletes. A second aim was also to measure how an information treatment about the benefits of edible insects would have impact on acceptance.

METHODS

61 Italian professional athletes (27 females) completed a structured questionnaire regarding supplements and eating habits, food neophobia, nutrition knowledge, willingness to taste edible insects and the associated factors. A question about sports endorsement was also posed at the end of the survey.

RESULTS

all subjects consumed supplements, generally recommended by medical personnel, even though their general knowledge of nutrition was poor (47.8%). Our main results shown that on a seven-point Likert scale, the protein content (5.74 ± 1.01) and the curiosity about texture (5.24 ± 0.98) were the main drivers to taste the cricket energy bar; whereas the feeling of disgust (5.58 ± 1.08) justified the rejection of tasting insects. In addition, the level of food neophobia increases with age (p < 0.05) and reduces willingness to endorse the cricket bar (p < 0.05). Male athletes (4.47 ± 1.69) were more likely to endorse the product than females (3.3 ± 1.49). An increase in willingness to taste was observed after the information treatment (z = 4.16, p < 0.001). Even though the population under investigation is unique, it is important to mention that this study involves a relatively small and convenience sample, and therefore generalizability of the results should be done with caution.

Analysis of the consumption of sports supplements in elite fencers according to sex and competitive level

Background

The aim of this study was to analyze the consumption of sports supplements (SS) in competitive level fencers and compare differences based on sex and competitive level (international and national).

Methods

A total of 49 fencers (18 men and 31 women) of national (n = 16) and international (n = 33) level completed a questionnaire with questions about SS consumption and the possible repercussions on health and / or sports performance. The results were analyzed based on the different categorizations established by the Australian Institute of Sport (AIS), as well as by sex and level of competence to which the participants belonged to.

Results

46.9% of fencers have consumed SS with the main motivation being performance improvement (34.2%). Medical doctors were the individuals who were more likely to advise men to consume SS (50.0% vs 5.6%; OR = 3.29 [1.50–7.20]). Friends were most likely to advise women (38.9% vs 8.3%; OR = 1.75 [1.05–2.93]). The most consumed SS were sport drinks (44.9%), vitamin C (43.4%), sport bars (38.8%), and caffeine (28.6%). In regards to the SS categories, it was observed differences in the interaction level·sex in medical supplements (p = 0.017). In addition, there was a higher prevalence of whey protein consumption in women (25.8% vs 0%; p = 0.020) and iron consumption in men (33% vs 6.5%; p = 0.039).

Conclusions

The prevalence of SS use in fencers is within the values previously reported in athletes of the same competitive level. There were no differences by sex and competitive level in the total consumption of SS, nor in each of the groups of level of evidence, being sport drinks, bars and caffeine the most consumed SS.

Increased cardiorespiratory stress during submaximal cycling after ketone monoester ingestion in endurance-trained adults

There is growing interest in the effect of exogenous ketone body supplementation on exercise responses and performance. The limited studies to date have yielded equivocal data, likely due in part to differences in dosing strategy, increase in blood ketones, and participant training status. Using a randomized, double-blind, counterbalanced design, we examined the effect of ingesting a ketone monoester (KE) supplement (600 mg/kg body mass) or flavour-matched placebo in endurance-trained adults (n = 10 males, n = 9 females; V̇O_2peak = 57 ± 8 mL/kg/min). Participants performed a 30-min cycling bout at ventilatory threshold intensity (71 ± 3% V̇O_2peak), followed 15 min later by a 3 kJ/kg body mass time-trial. KE versus placebo ingestion increased plasma β-hydroxybutyrate concentration before exercise (3.9 ± 1.0 vs 0.2 ± 0.3 mM, p < 0.0001, d_z = 3.4), ventilation (77 ± 17 vs 71 ± 15 L/min, p < 0.0001, d_z = 1.3) and heart rate (155 ± 11 vs 150 ± 11 beats/min, p < 0.001, d_z = 1.2) during exercise, and rating of perceived exertion at the end of exercise (15.4 ± 1.6 vs 14.5 ± 1.2, p < 0.01, d_z = 0.85). Plasma β-hydroxybutyrate concentration remained higher after KE vs placebo ingestion before the time-trial (3.5 ± 1.0 vs 0.3 ± 0.2 mM, p < 0.0001, d_z = 3.1), but performance was not different (KE: 16:25 ± 2:50 vs placebo: 16:06 ± 2:40 min:s, p = 0.20; d_z = 0.31). We conclude that acute ingestion of a relatively large KE bolus dose increased markers of cardiorespiratory stress during submaximal exercise in endurance-trained participants. Novelty: Limited studies have yielded equivocal data regarding exercise responses after acute ketone body supplementation. Using a randomized, double-blind, placebo-controlled, counterbalanced design, we found that ingestion of a large bolus dose of a commercial ketone monoester supplement increased markers of cardiorespiratory stress during cycling at ventilatory threshold intensity in endurance-trained adults.

Does the Nutritional Composition of Dairy Milk Based Recovery Beverages Influence Post-exercise Gastrointestinal and Immune Status, and Subsequent Markers of Recovery Optimisation in Response to High Intensity Interval Exercise?

This study aimed to determine the effects of flavored dairy milk based recovery beverages of different nutrition compositions on markers of gastrointestinal and immune status, and subsequent recovery optimisation markers. After completing 2 h high intensity interval running, participants (n = 9) consumed a whole food dairy milk recovery beverage (CM, 1.2 g/kg body mass (BM) carbohydrate and 0.4 g/kg BM protein) or a dairy milk based supplement beverage (MBSB, 2.2 g/kg BM carbohydrate and 0.8 g/kg BM protein) in a randomized crossover design. Venous blood samples, body mass, body water, and breath samples were collected, and gastrointestinal symptoms (GIS) were measured, pre- and post-exercise, and during recovery. Muscle biopsies were performed at 0 and 2 h of recovery. The following morning, participants returned to the laboratory to assess performance outcomes. In the recovery period, carbohydrate malabsorption (breath H2 peak: 49 vs. 24 ppm) occurred on MBSB compared to CM, with a trend toward greater gut discomfort. No difference in gastrointestinal integrity (i.e., I-FABP and sCD14) or immune response (i.e., circulating leukocyte trafficking, bacterially-stimulated neutrophil degranulation, and systemic inflammatory profile) markers were observed between CM and MBSB. Neither trial achieved a positive rate of muscle glycogen resynthesis [-25.8 (35.5) mmol/kg dw/h]. Both trials increased phosphorylation of intramuscular signaling proteins. Greater fluid retention (total body water: 86.9 vs. 81.9%) occurred on MBSB compared to CM. Performance outcomes did not differ between trials. The greater nutrient composition of MBSB induced greater gastrointestinal functional disturbance, did not prevent the post-exercise reduction in neutrophil function, and did not support greater overall acute recovery.

A Survey on Dietary Supplement Consumption in Amateur and Professional Rugby Players

Purpose: the aim of the present study was to analyse the pattern of dietary supplements (DS) consumption on federated rugby players, including the analysis of differences based on the sex and competitive level (professional vs. amateurs). Material and methods: 144 rugby players (83 male and 61 female), of whom 69 were professionals and 75 amateurs, were recruited for the study. All the participants filled out a specific questionnaire about DS consumption including questions related to the consumption of DS and their effects on sport performance and health status. Results: 65.3% of participants declared consuming at least one DS, with a higher prevalence in males than females (77.1% vs. 49.2%) and in professionals thanin amateur players (79.7% vs. 52.0%). The main reason for consumption was to enhance sport performance (62.3%) with differences only based on sex (74.3% males vs. 43.2% females). The most common purchase sites were the Internet (45.6%) and specialised stores (39.8%). As to the moment of ingestion, professionals did this most frequently during competition and training (56.4% vs. 28.2%), whereas amateur players did so only during competition (20.5% vs. 3.6%). Moreover, professional player intake most frequently in post-exercise (65.5% vs. 35.9%), whereas amateur during pre-exercise (30.8% vs. 5.5%). The DS most consumed included whey protein (44%), caffeine (42%), sports drinks (38%), energy bars (34%) and creatine monohydrate (31%), with a higher prevalence in male and professional players of whey protein and creatine monohydrate. Conclusions: The main reason for DS consumption is for enhancing sports performance). Professional players more frequently purchase them on the Internet and consume DS during training and competition period and in the post-exercise, whereas amateur players consume during competition and pre-exercise. Related to the main form of DS consumption, it is observed that a moderate consumption of DS could be considered ergogenic, such as whey protein, sport bar and creatine, while an absence of other DS could be considered ergogenic.

No Effects of New Zealand Blackcurrant Extract on Physiological and Performance Responses in Trained Male Cyclists Undertaking Repeated Testing across a Week Period

Anthocyanin supplements are receiving attention due to purported benefits to physiological, metabolic, and exercise responses in trained individuals. However, the efficacy of anthocyanin intake over multiple testing days is not known. We compared a placebo and two doses of anthocyanin-rich New Zealand blackcurrant (NZBC) extract (300 and 600 mg·day⁻¹) on plasma lactate, substrate oxidation, and 16.1 km time trial (TT) performance on three occasions over 7-days in a fed state (day 1 (D1), D4, and D7). Thirteen male cyclists participated in a randomized, crossover, placebo-controlled double-blind design. There was no difference in plasma lactate and substrate oxidation between conditions and between days. A time difference was observed between D1 (1701 ± 163 s) and D4 (1682 ± 162 s) for 600 mg (p = 0.05), with an increment in average speed (D1 = 34.3 ± 3.4 vs. D4 = 34.8 ± 3.4 km·h⁻¹, p = 0.04). However, there was no difference between the other days and between conditions. Overall, one week of intake of NZBC extract did not affect physiological and metabolic responses. Intake of 600 mg of NZBC extract showed inconsistent benefits in improving 16.1 km time trial performance over a week period in trained fed cyclists.

The effect of astaxanthin supplementation on performance and fat oxidation during a 40 km cycling time trial

OBJECTIVES

This study aimed to investigate whether supplementation with 12 mg⋅day^-1 astaxanthin for 7 days can improve exercise performance and metabolism during a 40 km cycling time trial.

DESIGN

A randomised, double-blind, crossover design was employed.

METHODS

Twelve recreationally trained male cyclists (VO_2peak: 56.5 ± 5.5 mL⋅kg^-1⋅min^-1, W_max: 346.8  ± 38.4 W) were recruited. Prior to each experimental trial, participants were supplemented with either 12 mg⋅day^-1 astaxanthin or an appearance-matched placebo for 7 days (separated by 14 days of washout). On day 7 of supplementation, participants completed a 40 km cycling time trial on a cycle ergometer, with indices of exercise metabolism measured throughout.

RESULTS

Time to complete the 40 km cycling time trial was improved by 1.2 ± 1.7% following astaxanthin supplementation, from 70.76 ± 3.93 min in the placebo condition to 69.90 ± 3.78 min in the astaxanthin condition (mean improvement = 51 ± 71 s, p = 0.029, g = 0.21). Whole-body fat oxidation rates were also greater (+0.09 ± 0.13 g⋅min^-1, p = 0.044, g = 0.52), and the respiratory exchange ratio lower (-0.03 ± 0.04, p = 0.024, g = 0.60) between 39-40 km in the astaxanthin condition.

CONCLUSIONS

Supplementation with 12 mg⋅day^-1 astaxanthin for 7 days provided an ergogenic benefit to 40 km cycling time trial performance in recreationally trained male cyclists and enhanced whole-body fat oxidation rates in the final stages of this endurance-type performance event.

No Benefit of Ingestion of a Ketone Monoester Supplement on 10-km Running Performance

PURPOSE

Preexercise ingestion of exogenous ketones alters the metabolic response to exercise, but effects on exercise performance have been equivocal.

METHODS

On two occasions in a double-blind, randomized crossover design, eight endurance-trained runners performed 1 h of submaximal exercise at approximately 65% V˙O2max immediately followed by a 10-km self-paced time trial (TT) on a motorized treadmill. An 8% carbohydrate-electrolyte solution was consumed before and during exercise, either alone (CHO + PLA), or with 573 mg·kg of a ketone monoester supplement (CHO + KME). Expired air, HR, and RPE were monitored during submaximal exercise. Serial venous blood samples were assayed for plasma glucose, lactate, and β-hydroxybutyrate concentrations.

RESULTS

CHO + KME produced plasma β-hydroxybutyrate concentrations of approximately 1.0 to 1.3 mM during exercise (P < 0.001), but plasma glucose and lactate concentrations were similar during exercise in both trials. V˙O2, running economy, respiratory exchange ratio, HR, and RPE were also similar between trials. Performance in the 10-km TT was not different (P = 0.483) between CHO + KME (mean, 2402 s; 95% confidence interval, 2204-2600 s) and CHO + PLA (mean, 2422 s; 95% confidence interval, 2217-2628 s). Cognitive performance, measured by reaction time and a multitasking test, did not differ between trials.

CONCLUSIONS

Compared with carbohydrate alone, coingestion of KME by endurance-trained athletes elevated plasma β-hydroxybutyrate concentrations, but did not improve 10-km running TT or cognitive performance.

No Differences Between Beetroot Juice and Placebo on Competitive 5-km Running Performance: A Double-Blind, Placebo-Controlled Trial

The authors examine the effect of an acute dose of beetroot juice on endurance running performance in "real-world" competitive settings. In total, 70 recreational runners (mean ± SD: age = 33.3 ± 12.3 years, training history = 11.9 ± 8.1 years, and hours per week training = 5.9 ± 3.5) completed a quasi-randomized, double-blind, placebo-controlled study of 5-km competitive time trials. Participants performed four trials separated by 1 week in the order of prebaseline, two experimental, and one postbaseline. Experimental trials consisted of the administration of 70-ml nitrate-rich beetroot juice (containing ∼4.1 mmol of nitrate, Beet It Sport®) or nitrate-depleted placebo (containing ∼0.04 mmol of nitrate, Beet It Sport®) 2.5 hr prior to time trials. Time to complete 5 km was recorded for each trial. No differences were shown between pre- and postbaseline (p = .128, coefficient variation = 2.66%). The average of these two trials is therefore used as baseline. Compared with baseline, participants ran faster with beetroot juice (mean differences = 22.2 ± 5.0 s, p < .001, d = 0.08) and placebo (22.9 ± 4.5 s, p < .001, d = 0.09). No differences in times were shown between beetroot juice and placebo (0.8 ± 5.7 s, p < .875, d = 0.00). These results indicate that an acute dose of beetroot juice does not improve competitive 5-km time-trial performance in recreational runners compared with placebo.

A Randomised, Placebo-Controlled, Crossover Study Investigating the Optimal Timing of a Caffeine-Containing Supplement for Exercise Performance

BACKGROUND

Pre-exercise supplements containing low doses of caffeine improve endurance exercise performance, but the most efficacious time for consumption before intense endurance exercise remains unclear, as does the contribution of caffeine metabolism.

METHODS

This study assessed the timing of a commercially available supplement containing 200 mg of caffeine, 1600 mg of β-alanine and 1000 mg of quercetin [Beachbody Performance Energize, Beachbody LLC, USA] on exercise performance, perception of effort and plasma caffeine metabolites. Thirteen cyclists (V̇O_2max 64.5 ± 1.4 ml kg^- 1 min^- 1 (± SEM)) completed four experimental visits consisting of 30 min of steady-state exercise on a cycle ergometer at 83 ± 1% V̇O_2max followed by a 15-min time trial, with perceived exertion measured regularly. On three of the visits, participants consumed caffeine either 35 min before steady-state exercise (PRE), at the onset of steady-state (ONS) or immediately before the time trial (DUR) phases, with a placebo consumed at the other two time points (i.e. three drinks per visit). The other visit (PLA) consisted of consuming the placebo supplement at all three time points. The placebo was taste-, colour- and calorie-matched.

RESULTS

Total work performed during the time trial in PRE was 5% greater than PLA (3.53 ± 0.14 vs. 3.36 ± 0.13 kJ kg^- 1 body mass; P = 0.0025), but not ONS (3.44 ± 0.13 kJ kg^- 1; P = 0.3619) or DUR (3.39 ± 0.13 kJ kg^- 1; P = 0.925), which were similar to PLA. Perceived exertion was lowest during steady-state exercise in the PRE condition (P < 0.05), which coincided with elevated plasma paraxanthine in PRE only (P < 0.05).

CONCLUSION

In summary, ingestion of a pre-exercise supplement containing 200 mg caffeine 35 min before exercise appeared optimal for improved performance in a subsequent fatiguing time trial, possibly by reducing the perception of effort. Whether this was due to increased circulating paraxanthine requires further investigation.

TRIAL REGISTRATION

ClinicalTrials.Gov, NCT02985606 ; 10/26/2016.

Casuistic Reasoning, Standards of Evidence, and Expertise on Elite Athletes’ Nutrition

This paper assesses the epistemic challenges of giving nutrition advice to elite athletes in light of recent philosophical discussion concerning evidence-based practice. Our trust in experts largely depends on the assumption that their advice is based on reliable evidence. In many fields, the evaluation of the reliability of evidence is made on the basis of standards that originate from evidence-based medicine. I show that at the Olympic or professional level, implementing nutritional plans in real-world competitions requires contextualization of knowledge in a way that contravenes the tenets of evidence-based thinking. Nutrition experts need to be able to combine and apply evidence from multiple sources, including the previous successes and failures of particular athletes. I argue that in this sense, the practice of elite sport nutrition embodies casuistic reasoning.

Swifter, higher, stronger: What’s on the menu?

The exploits of elite athletes delight, frustrate, and confound us as they strive to reach their physiological, psychological, and biomechanical limits. We dissect nutritional approaches to optimal performance, showcasing the contribution of modern sports science to gold medals and world titles. Despite an enduring belief in a single, superior “athletic diet,” diversity in sports nutrition practices among successful athletes arises from the specificity of the metabolic demands of different sports and the periodization of training and competition goals. Pragmatic implementation of nutrition strategies in real-world scenarios and the prioritization of important strategies when nutrition themes are in conflict add to this variation. Lastly, differences in athlete practices both promote and reflect areas of controversy and disagreement among sports nutrition experts.

Effects of a single dose of beetroot juice on cycling time trial performance at ventilatory thresholds intensity in male triathletes

Background

Beetroot juice (BJ) is classified as a high-level supplement for improving sports performance. There is some controversy over the benefits of BJ supplementation for endurance exercise performance, especially when referring to well-trained athletes. This study examines the effects of acute BJ supplementation on cardioventilatory responses, exercise economy/efficiency, slow component of oxygen uptake, time trial performance, blood lactate, energy consumption, and carbohydrate and fat oxidation.

Methods

Twelve well-trained, male triathletes (aged 21–47 yr) were assigned in a randomized, double-blind, crossover design to receive 70 ml of BJ (6.5 mmol NO₃⁻) or placebo (PL). Three hours after taking the supplement, participants completed an endurance test on a cycle ergometer at a constant work rate (W) corresponding to first ventilatory threshold (VT1) (30 min) and second ventilatory threshold (VT2) time trial (~ 15 min).

Results

Maximal oxygen uptake was 54.78 ± 3.13 mL·min^− 1·kg^− 1, and gross efficiency was > 22% at each load intensity and experimental condition. No significant interaction effect (supplement*intensity) was observed on any of the cardioventilatory variables, efficiency/economy, VT2 time trial, energy expenditure, carbohydrate oxidation and fat oxidation (p > 0.05).

Conclusion

Our findings do not support an improvement in the variables examined in response to acute BJ supplementation. Probably, higher doses are needed for improving time trial performance in male triathletes during a cycle ergometer test conducted at a load intensity equivalent to the first and second ventilatory threshold.

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.