scholarly journals Neither Beetroot Juice Supplementation nor Increased Carbohydrate Oxidation Enhance Economy of Prolonged Exercise in Elite Race Walkers

Nutrients ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 2767
Author(s):  
Louise M. Burke ◽  
Rebecca Hall ◽  
Ida A. Heikura ◽  
Megan L. Ross ◽  
Nicolin Tee ◽  
...  
Keyword(s):  
Elite Athletes ◽  
Endurance Performance ◽  
Beetroot Juice ◽  
Future Studies ◽  
Exercise Economy ◽  
Parallel Group ◽  
Performance Effects ◽  
Race Walking ◽  
The Impact ◽  
Current Guidelines

Given the importance of exercise economy to endurance performance, we implemented two strategies purported to reduce the oxygen cost of exercise within a 4 week training camp in 21 elite male race walkers. Fourteen athletes undertook a crossover investigation with beetroot juice (BRJ) or placebo (PLA) [2 d preload, 2 h pre-exercise + 35 min during exercise] during a 26 km race walking at speeds simulating competitive events. Separately, 19 athletes undertook a parallel group investigation of a multi-pronged strategy (MAX; n = 9) involving chronic (2 w high carbohydrate [CHO] diet + gut training) and acute (CHO loading + 90 g/h CHO during exercise) strategies to promote endogenous and exogenous CHO availability, compared with strategies reflecting lower ranges of current guidelines (CON; n = 10). There were no differences between BRJ and PLA trials for rates of CHO (p = 0.203) or fat (p = 0.818) oxidation or oxygen consumption (p = 0.090). Compared with CON, MAX was associated with higher rates of CHO oxidation during exercise, with increased exogenous CHO use (CON; peak = ~0.45 g/min; MAX: peak = ~1.45 g/min, p < 0.001). High rates of exogenous CHO use were achieved prior to gut training, without further improvement, suggesting that elite athletes already optimise intestinal CHO absorption via habitual practices. No differences in exercise economy were detected despite small differences in substrate use. Future studies should investigate the impact of these strategies on sub-elite athletes’ economy as well as the performance effects in elite groups.

No Improvement in Endurance Performance after a Single Dose of Beetroot Juice

2012 ◽  
Vol 22 (6) ◽  
pp. 470-478 ◽  
Author(s):  
Naomi M. Cermak ◽  
Peter Res ◽  
Rudi Stinkens ◽  
Jon O. Lundberg ◽  
Martin J. Gibala ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Time Trial ◽  
Endurance Performance ◽  
Beetroot Juice ◽  
Double Blind ◽  
Single Bolus ◽  
Time Trial Performance ◽  
Subsequent Time ◽  
The Impact ◽  
Trial Performance

Introduction:Dietary nitrate supplementation has received much attention in the literature due to its proposed ergogenic properties. Recently, the ingestion of a single bolus of nitrate-rich beetroot juice (500 ml, ~6.2 mmol NO3−) was reported to improve subsequent time-trial performance. However, this large volume of ingested beetroot juice does not represent a realistic dietary strategy for athletes to follow in a practical, performancebased setting. Therefore, we investigated the impact of ingesting a single bolus of concentrated nitrate-rich beetroot juice (140 ml, ~8.7 mmol NO3−) on subsequent 1-hr time-trial performance in well-trained cyclists.Methods:Using a double-blind, repeated-measures crossover design (1-wk washout period), 20 trained male cyclists (26 ± 1 yr, VO2peak 60 ± 1 ml · kg−1 · min−1, Wmax 398 ± 7.7 W) ingested 140 ml of concentrated beetroot juice (8.7 mmol NO3−; BEET) or a placebo (nitrate-depleted beetroot juice; PLAC) with breakfast 2.5 hr before an ~1-hr cycling time trial (1,073 ± 21 kJ). Resting blood samples were collected every 30 min after BEET or PLAC ingestion and immediately after the time trial.Results:Plasma nitrite concentration was higher in BEET than PLAC before the onset of the time trial (532 ± 32 vs. 271 ± 13 nM, respectively; p < .001), but subsequent time-trial performance (65.5 ± 1.1 vs. 65 ± 1.1 s), power output (275 ± 7 vs. 278 ± 7 W), and heart rate (170 ± 2 vs. 170 ± 2 beats/min) did not differ between BEET and PLAC treatments (all p > .05).Conclusion:Ingestion of a single bolus of concentrated (140 ml) beetroot juice (8.7 mmol NO3−) does not improve subsequent 1-hr time-trial performance in well-trained cyclists.

scholarly journals A Fundamental Study on the Development of New Energy Performance Index in Office Buildings

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2064
Author(s):  
Jin-Hee Kim ◽  
Seong-Koo Son ◽  
Gyeong-Seok Choi ◽  
Young-Tag Kim ◽  
Sung-Bum Kim ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Energy Requirement ◽  
Energy Performance ◽  
Office Buildings ◽  
Light Transmittance ◽  
Wall Structure ◽  
Fundamental Study ◽  
Future Studies ◽  
U Value ◽  
The Impact

Recently, there have been significant concerns regarding excessive energy use in office buildings with a large window-to-wall ratio (WWR) because of the curtain wall structure. However, prior research has confirmed that the impact of the window area on energy consumption varies depending on building size. A newly proposed window-to-floor ratio (WFR) correlates better with energy consumption in the building. In this paper, we derived the correlation by analyzing a simulation using EnergyPlus, and the results are as follows. In the case of small buildings, the results of this study showed that the WWR and energy requirement increase proportionally, and the smaller the size is, the higher the energy sensitivity will be. However, results also confirmed that this correlation was not established for buildings approximately 3600 m2 or larger. Nevertheless, from analyzing the correlation between the WFR and the energy requirements, it could be deduced that energy required increased proportionally when the WFR was 0.1 or higher. On the other hand, the correlation between WWR, U-value, solar heat gain coefficient (SHGC), and material property values of windows had little effect on energy when the WWR was 20%, and the highest effect was seen at a WWR of 100%. Further, with an SHGC below 0.3, the energy requirement decreased with an increasing WWR, regardless of U-value. In addition, we confirmed the need for in-depth research on the impact of the windows’ U-value, SHGC, and WWR, and this will be verified through future studies. In future studies on window performance, U-value, SHGC, visible light transmittance (VLT), wall U-value as sensitivity variables, and correlation between WFR and building size will be examined.

scholarly journals Efficacy of Popular Diets Applied by Endurance Athletes on Sports Performance: Beneficial or Detrimental? A Narrative Review

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 491
Author(s):  
Aslı Devrim-Lanpir ◽  
Lee Hill ◽  
Beat Knechtle
Keyword(s):  
Gastrointestinal Symptoms ◽  
Endurance Performance ◽  
Endurance Athletes ◽  
Intermittent Fasting ◽  
Nutritional Strategy ◽  
Current Perspective ◽  
Vegetarian Diets ◽  
Fat Diets ◽  
The Impact ◽  
Harsh Conditions

Endurance athletes need a regular and well-detailed nutrition program in order to fill their energy stores before training/racing, to provide nutritional support that will allow them to endure the harsh conditions during training/race, and to provide effective recovery after training/racing. Since exercise-related gastrointestinal symptoms can significantly affect performance, they also need to develop strategies to address these issues. All these factors force endurance athletes to constantly seek a better nutritional strategy. Therefore, several new dietary approaches have gained interest among endurance athletes in recent decades. This review provides a current perspective to five popular diet approaches: (a) vegetarian diets, (b) high-fat diets, (c) intermittent fasting diets, (d) gluten-free diet, and (e) low fermentable oligosaccharides, disaccharides, monosaccharides and polyols (FODMAP) diets. We reviewed scientific studies published from 1983 to January 2021 investigating the impact of these popular diets on the endurance performance and health aspects of endurance athletes. We also discuss all the beneficial and harmful aspects of these diets, and offer key suggestions for endurance athletes to consider when following these diets.

Electrically-induced quadriceps fatigue in the contralateral leg impairs ipsilateral knee extensors performance

2021 ◽  
Author(s):  
Fabio Giuseppe Laginestra ◽  
Markus Amann ◽  
Emine Kirmizi ◽  
Gaia Giuriato ◽  
Chiara Barbi ◽  
...  
Keyword(s):  
Muscle Activation ◽  
Central Fatigue ◽  
Endurance Performance ◽  
Voluntary Exercise ◽  
Peripheral Fatigue ◽  
Knee Extensors ◽  
Motor Drive ◽  
Time To Exhaustion ◽  
Crossover Effect ◽  
The Impact

Muscle fatigue induced by voluntary exercise, which requires central motor drive, causes central fatigue that impairs endurance performance of a different, non-fatigued muscle. This study investigated the impact of quadriceps fatigue induced by electrically-induced (no central motor drive) contractions on single-leg knee-extension (KE) performance of the subsequently exercising ipsilateral quadriceps. On two separate occasions, eight males completed constant-load (85% of maximal power-output) KE exercise to exhaustion. In a counterbalanced manner, subjects performed the KE exercise with no pre-existing quadriceps fatigue in the contralateral leg on one day (No-PreF), while on the other day, the same KE exercise was repeated following electrically-induced quadriceps fatigue in the contralateral leg (PreF). Quadriceps fatigue was assessed by evaluating pre- to post-exercise changes in potentiated twitch force (ΔQtw,pot; peripheral-fatigue), and voluntary muscle activation (ΔVA; central-fatigue). As reflected by the 57±11% reduction in electrically-evoked pulse force, the electrically-induced fatigue protocol caused significant knee-extensors fatigue. KE endurance time to exhaustion was shorter during PreF compared to No-PreF (4.6±1.2 vs 7.7±2.4 min; p<0.01). While ΔQtw,pot was significantly larger in No-PreF compared to PreF (-60% vs -52%, p<0.05), ΔVA was greater in PreF (-14% vs -10%, p<0.05). Taken together, electrically-induced quadriceps fatigue in the contralateral leg limits KE endurance performance and the development of peripheral fatigue in the ipsilateral leg. These findings support the hypothesis that the crossover-effect of central fatigue is mainly mediated by group III/IV muscle afferent feedback and suggest that impairments associated with central motor drive may only play a minor role in this phenomenon.

Reflections on the biochemistry ofEchinococcus: past, present and future

Parasitology ◽  
2009 ◽  
Vol 136 (12) ◽  
pp. 1643-1652 ◽  
Author(s):  
D. P. McMANUS
Keyword(s):  
Hydatid Disease ◽  
Biochemical Analysis ◽  
Species Variation ◽  
Research Directions ◽  
Future Studies ◽  
Tegumental Surface ◽  
Research Areas ◽  
General Metabolism ◽  
New Research ◽  
The Impact

SUMMARYThis review discusses 5 of my earliest papers on the biochemistry of larvalEchinococcuspublished inParasitologyin the 1970s and 1980s. Two of the publications consider aspects of the basic biochemistry, intermediary metabolism and the regulation of respiratory pathways inE. granulosusandE. multilocularis, and emphasize the existence of inter- and intra-species variation in their general metabolism. The third reports on the detailed biochemical analysis of the tegumental surface of the protoscolex ofE. granulosus, and the final 2 papers describe the genomic cloning ofEchinococcusDNA fragments and their use, along with other DNA markers, in molecular identification ofE. granulosusisolates collected worldwide from areas endemic for hydatid disease. A number of years have elapsed since these publications inParasitologyand, in this Centenary Issue article, I reflect briefly on some of the subsequent studies undertaken in these research areas that have advanced the field. As well, I provide brief insight on new research directions, emphasizing the impact of molecular biology and associated techniques on future studies ofEchinococcusand hydatid disease.

scholarly journals #GERIATRICS: AN ANALYSIS OF THE IMPACT OF THE GERIATRICS TWITTER NETWORK

2019 ◽  
Vol 3 (Supplement_1) ◽  
pp. S337-S337
Author(s):  
Varun Ayyaswami ◽  
Arpan Prabhu ◽  
Steven Gambert
Keyword(s):  
Network Analysis ◽  
Geriatric Medicine ◽  
The United States ◽  
Annual Growth ◽  
Social Media Analytics ◽  
User Characteristics ◽  
Future Studies ◽  
Digital Community ◽  
Support Organizations ◽  
The Impact

Abstract Twitter connects an international community of healthcare stakeholders, potentially augmenting access to information related to geriatric medicine. The purpose of this study is to analyze the geriatric medicine Twitter network, and we hypothesize this community has substantially grown in the last six years. We analyzed all publicly available tweets including the hashtag #geriatrics from January 1, 2013-January 1, 2019 using Symplur Signals, a health care social media analytics platform. We evaluated #geriatrics metrics over time related to activity, content analysis, user characteristics, engagement, and network analysis. A total of 159,008 tweets (containing 42.8% re-tweets) with the hashtag #geriatrics were written by 29,443 users, resulting in 393.6 million impressions. The number of tweets increased from 9,705 in 2013 to 39,151 in 2018 (32.2% compound annual growth); users increased from 3,366 in 2013 to 29,443 in 2018 (55.3% compound annual growth). Users were primarily found in the United States, United Kingdom, and Canada. The most commonly trending topic from 2013-2015 and from 2016-2018 was ‘older adults’. The top hashtags included in tweets with #geriatrics were #job, #aging, and #hpm (hospice and palliative medicine). Network analysis showed central hubs to be medical journals, provider organizations, individual physicians, and individual advocates. The top 150 influencers consisted primarily of physicians (49.1%), advocate/support organizations (13.8%), and media organizations (6.3%). The use of Twitter to promote geriatric medicine using #geriatrics has matured into an international digital community of interest. Future studies should examine hashtags related to age prevalent illnesses and hashtags likely to be used by patients.

scholarly journals Vascular access: the impact of ultrasonography

2016 ◽  
Vol 14 (4) ◽  
pp. 561-566 ◽  
Author(s):  
Carlos Eduardo Saldanha de Almeida ◽  
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Critically Ill ◽  
Vascular Access ◽  
Critically Ill Patients ◽  
Albert Einstein ◽  
Sao Paulo ◽  
Future Studies ◽  
The Impact ◽  
Puncture Technique

ABSTRACT Vascular punctures are often necessary in critically ill patients. They are secure, but not free of complications. Ultrasonography enhances safety of the procedure by decreasing puncture attempts, complications and costs. This study reviews important publications and the puncture technique using ultrasound, bringing part of the experience of the intensive care unit of the Hospital Israelita Albert Einstein, São Paulo (SP), Brazil, and discussing issues that should be considered in future studies.

scholarly journals Can Intentional Distractions Affect Endurance Performance Positively?

2021 ◽  
Vol 4 (1) ◽  
pp. 15
Author(s):  
Roger Couture
Keyword(s):  
Perceived Exertion ◽  
Endurance Performance ◽  
Residual Effects ◽  
Ratings Of Perceived Exertion ◽  
Future Studies ◽  
Performance Time ◽  
Performance Change ◽  
Confounding Variables ◽  
Improved Performance ◽  
Active Distraction

Distractions are often associated with negative outcomes however, distractions can also benefit people. Using the hypothesis of internal-external distractions in the competition for cue, this study examined the effects of an active (controlled) and passive (uncontrolled) distraction on three endurance tasks. Participants (N=42), aged 20 to 23 years were assigned to three groups. Tasks and conditions were counterbalanced across groups to minimize the residual effects of fatigue, learning an intervention and other confounding variables. Performance time, heart rate, ratings of perceived exertion and perceived fatigue were measured. Results showed that active distraction significantly improved performance and lowered Rate of Perceived Exertion in one task. As expected, the active distraction group was the least accurate for estimating time spent. Passive distraction caused minimal performance change. More investigation is needed to understand why an active distraction only affected one trial. Future studies should delve into means for better understanding the hypothesis of competition for cue.

scholarly journals Is There a Link between Oropharyngeal Microbiome and Schizophrenia? A Narrative Review

2022 ◽  
Vol 23 (2) ◽  
pp. 846
Author(s):  
Stanislas Martin ◽  
Audrey Foulon ◽  
Wissam El Hage ◽  
Diane Dufour-Rainfray ◽  
Frédéric Denis
Keyword(s):  
Periodontal Disease ◽  
Research Team ◽  
Oral Microbiome ◽  
Oral Microbiota ◽  
Future Studies ◽  
The Subject ◽  
The Moment ◽  
The Impact ◽  
The Brain

The study aimed to examine the impact of the oropharyngeal microbiome in the pathophysiology of schizophrenia and to clarify whether there might be a bidirectional link between the oral microbiota and the brain in a context of dysbiosis-related neuroinflammation. We selected nine articles including three systemic reviews with several articles from the same research team. Different themes emerged, which we grouped into 5 distinct parts concerning the oropharyngeal phageome, the oropharyngeal microbiome, the salivary microbiome and periodontal disease potentially associated with schizophrenia, and the impact of drugs on the microbiome and schizophrenia. We pointed out the presence of phageoma in patients suffering from schizophrenia and that periodontal disease reinforces the role of inflammation in the pathophysiology of schizophrenia. Moreover, saliva could be an interesting substrate to characterize the different stages of schizophrenia. However, the few studies we have on the subject are limited in scope, and some of them are the work of a single team. At this stage of knowledge, it is difficult to conclude on the existence of a bidirectional link between the brain and the oral microbiome. Future studies on the subject will clarify these questions that for the moment remain unresolved.

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