scholarly journals What Should I Eat before Exercise? Pre-Exercise Nutrition and the Response to Endurance Exercise: Current Prospective and Future Directions

Nutrients ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 3473
Author(s):  
Jeffrey A. Rothschild ◽  
Andrew E. Kilding ◽  
Daniel J. Plews
Keyword(s):  
Endurance Training ◽  
Current Knowledge ◽  
Exercise Duration ◽  
Future Research ◽  
Carbohydrate Ingestion ◽  
Training Performance ◽  
Performance Improvements ◽  
And Performance ◽  
Exercise Induced ◽  
Intensity Of Exercise

The primary variables influencing the adaptive response to a bout of endurance training are exercise duration and exercise intensity. However, altering the availability of nutrients before and during exercise can also impact the training response by modulating the exercise stimulus and/or the physiological and molecular responses to the exercise-induced perturbations. The purpose of this review is to highlight the current knowledge of the influence of pre-exercise nutrition ingestion on the metabolic, physiological, and performance responses to endurance training and suggest directions for future research. Acutely, carbohydrate ingestion reduces fat oxidation, but there is little evidence showing enhanced fat burning capacity following long-term fasted-state training. Performance is improved following pre-exercise carbohydrate ingestion for longer but not shorter duration exercise, while training-induced performance improvements following nutrition strategies that modulate carbohydrate availability vary based on the type of nutrition protocol used. Contrasting findings related to the influence of acute carbohydrate ingestion on mitochondrial signaling may be related to the amount of carbohydrate consumed and the intensity of exercise. This review can help to guide athletes, coaches, and nutritionists in personalizing pre-exercise nutrition strategies, and for designing research studies to further elucidate the role of nutrition in endurance training adaptations.

scholarly journals Metabolomics Biomarkers for Detection of Colorectal Neoplasms: A Systematic Review

Cancers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 246 ◽  
Author(s):  
Vanessa Erben ◽  
Megha Bhardwaj ◽  
Petra Schrotz-King ◽  
Hermann Brenner
Keyword(s):  
Early Detection ◽  
Colorectal Neoplasms ◽  
Literature Search ◽  
Web Of Science ◽  
Current Knowledge ◽  
External Validation ◽  
Performance Characteristics ◽  
Future Research ◽  
Non Invasive ◽  
And Performance

Background: Several approaches have been suggested to be useful in the early detection of colorectal neoplasms. Since metabolites are closely related to the phenotype and are available from different human bio-fluids, metabolomics are candidates for non-invasive early detection of colorectal neoplasms. Objectives: We aimed to summarize current knowledge on performance characteristics of metabolomics biomarkers that are potentially applicable in a screening setting for the early detection of colorectal neoplasms. Design: We conducted a systematic literature search in PubMed and Web of Science and searched for biomarkers for the early detection of colorectal neoplasms in easy-to-collect human bio-fluids. Information on study design and performance characteristics for diagnostic accuracy was extracted. Results: Finally, we included 41 studies in our analysis investigating biomarkers in different bio-fluids (blood, urine, and feces). Although single metabolites mostly had limited ability to distinguish people with and without colorectal neoplasms, promising results were reported for metabolite panels, especially amino acid panels in blood samples, as well as nucleosides in urine samples in several studies. However, validation of the results is limited. Conclusions: Panels of metabolites consisting of amino acids in blood and nucleosides in urinary samples might be useful biomarkers for early detection of advanced colorectal neoplasms. However, to make metabolomic biomarkers clinically applicable, future research in larger studies and external validation of the results is required.

scholarly journals Iron Regulation in Athletes: Exploring the Menstrual Cycle and Effects of Different Exercise Modalities on Hepcidin Production

2014 ◽  
Vol 24 (2) ◽  
pp. 177-187 ◽  
Author(s):  
Marc Sim ◽  
Brian Dawson ◽  
Grant Landers ◽  
Debbie Trinder ◽  
Peter Peeling
Keyword(s):  
Oral Contraceptive ◽  
Inflammatory Cytokine ◽  
Iron Absorption ◽  
Current Knowledge ◽  
Oral Contraceptive Pill ◽  
Well Being ◽  
The Body ◽  
Iron Regulation ◽  
Future Research ◽  
Exercise Induced

The trace element iron plays a number of crucial physiological roles within the body. Despite its importance, iron deficiency remains a common problem among athletes. As an individual’s iron stores become depleted, it can affect their well-being and athletic capacity. Recently, altered iron metabolism in athletes has been attributed to postexercise increases in the iron regulatory hormone hepcidin, which has been reported to be upregulated by exercise-induced increases in the inflammatory cytokine interleukin-6. As such, when hepcidin levels are elevated, iron absorption and recycling may be compromised. To date, however, most studies have explored the acute postexercise hepcidin response, with limited research seeking to minimize/attenuate these increases. This review summarizes the current knowledge regarding the postexercise hepcidin response under a variety of exercise scenarios and highlights potential areas for future research—such as: a) the use of hormones though the female oral contraceptive pill to manipulate the postexercise hepcidin response, b) comparing the use of different exercise modes (e.g., cycling vs. running) on hepcidin regulation.

Exercise-induced cardiac preconditioning: how exercise protects your achy-breaky heart

2011 ◽  
Vol 111 (3) ◽  
pp. 905-915 ◽  
Author(s):  
Chad R. Frasier ◽  
Russell L. Moore ◽  
David A. Brown
Keyword(s):  
Ischemia Reperfusion ◽  
Epidemiological Studies ◽  
Review Article ◽  
Buffering Capacity ◽  
Future Research ◽  
Cardiac Mitochondria ◽  
Exercise Preconditioning ◽  
Cardiac Preconditioning ◽  
Exercise Induced ◽  
Intensity Of Exercise

The ability of exercise to protect the heart against ischemia-reperfusion (I/R) injury is well known in both human epidemiological studies and experimental animal models. In this review article, we describe what is currently known about the ability of exercise to precondition the heart against infarction. Just 1 day of exercise can protect the heart against ischemia/reperfusion damage, and this protection is upheld with months of exercise, making exercise one of the few sustainable preconditioning stimuli. Exercise preconditioning depends on the model and intensity of exercise, and appears to involve heightened oxidant buffering capacity, upregulated subunits of sarcolemmal ATP-sensitive potassium channels, and adaptations to cardiac mitochondria. We review the putative mechanisms involved in exercise preconditioning and point out many areas where future research is necessary to advance our understanding of how this stimulus confers resistance against I/R damage.

The relationship of personality to cognitive characteristics and SME performance in Tanzania

2018 ◽  
Vol 25 (4) ◽  
pp. 667-686 ◽  
Author(s):  
Nsubili Isaga
Keyword(s):  
Personality Traits ◽  
Structural Equation ◽  
Current Knowledge ◽  
Future Research ◽  
Content Type ◽  
Cognitive Characteristics ◽  
Entrepreneurial Characteristics ◽  
Medium Enterprise ◽  
And Performance ◽  
The Relationship

PurposeFocussing on the relationship between personality traits and small and medium enterprise (SME) performance in Tanzania’s furniture sector, the purpose of this paper is to examine the effect of cognitive characteristics as a mediating variable.Design/methodology/approachA total of 300 SMEs in furniture sectors from four different regions in Tanzania were involved in this study. Structural equation modelling approach was used to test simultaneously the direct and the indirect effects of the characteristics of the entrepreneurs on the SMEs performance.FindingsThe findings show that personality traits have a significant influence on SMEs performance through cognitive characteristics.Research limitations/implicationsThe study’s data were collected from businesses in only one industry (furniture) in Tanzania. Future research may extend the approach to other business sectors.Practical implicationsSince entrepreneurial characteristics are considered an important driver of a country’s economic development and performance, it is hoped that governments and sector associations implement suitable policies and incentives to develop an entrepreneurial culture among citizens.Originality/valueCurrent knowledge about entrepreneurial characteristics and their relationship with SME performance in developing countries, especially Tanzania, is very limited. The present study suggests that cognitive characteristics are necessary mediators of the link between personality traits and SME performance.

scholarly journals Review of environmental performance of permeable pavement systems: state of the knowledge

2013 ◽  
Vol 48 (3) ◽  
pp. 203-222 ◽  
Author(s):  
Jennifer A. P. Drake ◽  
Andrea Bradford ◽  
Jiri Marsalek
Keyword(s):  
Environmental Performance ◽  
Current Knowledge ◽  
Polyaromatic Hydrocarbons ◽  
Future Research ◽  
Permeable Pavement ◽  
Current State ◽  
Pollutant Concentrations ◽  
The Usa ◽  
Guidance Documents ◽  
And Performance

Permeable pavement (PP) systems provide opportunities to mitigate the impacts of urbanization on receiving water systems by providing at source treatment and management of stormwater. However, they do not receive mainstream use throughout much of Canada and the USA because of a lack of local guidance documents, demonstration projects and performance data. Studies have repeatedly shown that PPs attenuate stormwater flows by reducing volume and frequency of stormwater flows, reducing and delaying peak flow rates, and increasing flow durations. PP systems have been shown to improve stormwater quality by reducing stormwater temperature, pollutant concentrations and pollutant loadings of suspended solids, heavy metals, polyaromatic hydrocarbons, and some nutrients. This review is intended as a comprehensive summary of the current state of knowledge of the environmental performance of PP systems. Published research is synthesized to examine the hydrologic performance, impacts to water quality, longevity and functionality and maintenance needs of PP systems. Where appropriate, the limitations of current knowledge are discussed and emerging and future research needs are presented. The intent of this review is to provide stakeholders in stormwater management with the critical information that is needed to foster acceptance of PPs as a viable alternative to traditional systems.

Aging and Recovery After Resistance-Exercise-Induced Muscle Damage: Current Evidence and Implications for Future Research

2020 ◽  
pp. 1-8
Author(s):  
John F.T. Fernandes ◽  
Kevin L. Lamb ◽  
Jonathan P. Norris ◽  
Jason Moran ◽  
Benjamin Drury ◽  
...  
Keyword(s):  
Resistance Training ◽  
Muscle Damage ◽  
Muscle Soreness ◽  
Current Knowledge ◽  
Age Groups ◽  
Current Evidence ◽  
Future Research ◽  
Exercise Induced ◽  
Aging Muscle ◽  
Older Populations

Aging is anecdotally associated with a prolonged recovery from resistance training, though current literature remains equivocal. This brief review considers the effects of resistance training on indirect markers of muscle damage and recovery (i.e., muscle soreness, blood markers, and muscle strength) in older males. With no date restrictions, four databases were searched for articles relating to aging, muscle damage, and recovery. Data from 11 studies were extracted for review. Of these, four reported worse symptoms in older compared with younger populations, while two have observed the opposite, and the remaining studies (n = 6) proposed no differences between age groups. It appears that resistance training can be practiced in older populations without concern for impaired recovery. To improve current knowledge, researchers are urged to utilize more ecologically valid muscle-damaging bouts and investigate the mechanisms which underpin the recovery of muscle soreness and strength after exercise in older populations.

scholarly journals Employee engagement and performance: a systematic literature review

2018 ◽  
Vol 54 (3) ◽  
pp. 227-244 ◽  
Author(s):  
Błażej Motyka
Keyword(s):  
Employee Engagement ◽  
Work Engagement ◽  
Work Performance ◽  
Current Knowledge ◽  
The Body ◽  
Future Research ◽  
Significant Relation ◽  
Economic Problems ◽  
And Performance ◽  
Academic Implications

AbstractScholars and practitioners indicate that low level of employee engagement at work is currently one of the most alarming global economic problems. The potential consequence of this phenomenon is declining work performance. Therefore, it becomes important to understand the concept of work engagement, its meaning for employees, and implications for employers. The article is a systematic review of the body of literature, presenting the results of research on the association between employee engagement and various performance categories. The paper’s objective is to summarize prior studies based on their ordering and categorization, identify gaps in the current knowledge, and propose an agenda for future research. The article presents these findings in a synthetic manner, offering practical and academic implications arising therefrom. Results of the review indicate that, in the case of most peer-reviewed publications, a statistically significant relation between employee engagement and numerous categories and subcategories of performance was confirmed.

Effects of Antioxidant Supplementation and Exercise Training on Erythrocyte Antioxidant Enzymes

2006 ◽  
Vol 76 (5) ◽  
pp. 324-331 ◽  
Author(s):  
Marsh ◽  
Laursen ◽  
Coombes
Keyword(s):  
Antioxidant Enzymes ◽  
Exercise Training ◽  
Endurance Training ◽  
Young Male ◽  
Antioxidant Defenses ◽  
Antioxidant Enzyme Activities ◽  
Antioxidant Supplementation ◽  
Male Wistar Rats ◽  
Exercise Induced ◽  
Antioxidant Supplements

Erythrocytes transport oxygen to tissues and exercise-induced oxidative stress increases erythrocyte damage and turnover. Increased use of antioxidant supplements may alter protective erythrocyte antioxidant mechanisms during training. Aim of study: To examine the effects of antioxidant supplementation (α-lipoic acid and α-tocopherol) and/or endurance training on the antioxidant defenses of erythrocytes. Methods: Young male Wistar rats were assigned to (1) sedentary; (2) sedentary and antioxidant-supplemented; (3) endurance-trained; or (4) endurance-trained and antioxidant-supplemented groups for 14 weeks. Erythrocyte superoxide dismutase (SOD), glutathione peroxidase (GPX), and catalase (CAT) activities, and plasma malondialdehyde (MDA) were then measured. Results: Antioxidant supplementation had no significant effect (p > 0.05) on activities of antioxidant enzymes in sedentary animals. Similarly, endurance training alone also had no effect (p > 0.05). GPX (125.9 ± 2.8 vs. 121.5 ± 3.0 U.gHb–1, p < 0.05) and CAT (6.1 ± 0.2 vs. 5.6 ± 0.2 U.mgHb–1, p < 0.05) activities were increased in supplemented trained animals compared to non-supplemented sedentary animals whereas SOD (61.8 ± 4.3 vs. 52.0 ± 5.2 U.mgHb–1, p < 0.05) activity was decreased. Plasma MDA was not different among groups (p > 0.05). Conclusions: In a rat model, the combination of exercise training and antioxidant supplementation increased antioxidant enzyme activities (GPX, CAT) compared with each individual intervention.

Materials Issues and Characterization of Low-k Dielectric Materials

MRS Bulletin ◽  
1997 ◽  
Vol 22 (10) ◽  
pp. 49-54 ◽  
Author(s):  
E. Todd Ryan ◽  
Andrew J. McKerrow ◽  
Jihperng Leu ◽  
Paul S. Ho
Keyword(s):  
Process Integration ◽  
Dielectric Materials ◽  
Propagation Delay ◽  
Thermomechanical Properties ◽  
General Criterion ◽  
Crosstalk Noise ◽  
Total Delay ◽  
Interlayer Dielectrics ◽  
Performance Improvements ◽  
And Performance

Continuing improvement in device density and performance has significantly affected the dimensions and complexity of the wiring structure for on-chip interconnects. These enhancements have led to a reduction in the wiring pitch and an increase in the number of wiring levels to fulfill demands for density and performance improvements. As device dimensions shrink to less than 0.25 μm, the propagation delay, crosstalk noise, and power dissipation due to resistance-capacitance (RC) coupling become significant. Accordingly the interconnect delay now constitutes a major fraction of the total delay limiting the overall chip performance. Equally important is the processing complexity due to an increase in the number of wiring levels. This inevitably drives cost up by lowering the manufacturing yield due to an increase in defects and processing complexity.To address these problems, new materials for use as metal lines and interlayer dielectrics (ILDs) and alternative architectures have surfaced to replace the current Al(Cu)/SiO2 interconnect technology. These alternative architectures will require the introduction of low-dielectric-constant k materials as the interlayer dielectrics and/or low-resistivity conductors such as copper. The electrical and thermomechanical properties of SiO2 are ideal for ILD applications, and a change to material with different properties has important process-integration implications. To facilitate the choice of an alternative ILD, it is necessary to establish general criterion for evaluating thin-film properties of candidate low-k materials, which can be later correlated with process-integration problems.

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