scholarly journals The Physiological Effects of Amino Acids Arginine and Citrulline: Is There a Basis for Development of a Beverage to Promote Endurance Performance? A Narrative Review of Orally Administered Supplements

Beverages ◽  
2020 ◽  
Vol 6 (1) ◽  
pp. 11 ◽  
Author(s):  
Hollie Speer ◽  
Nathan M. D’Cunha ◽  
Michael J. Davies ◽  
Andrew J. McKune ◽  
Nenad Naumovski
Keyword(s):  
Synergistic Effects ◽  
Endurance Performance ◽  
Performance Outcomes ◽  
Time To Exhaustion ◽  
No Production ◽  
Full Potential ◽  
Physiological Effects ◽  
And Performance ◽  
Physiological Benefits ◽  
Endothelial Nitric Oxide

Nutritional and ergogenic aid supplementation is prevalent within athletic or general fitness populations, and is only continuing to gain momentum. Taken in isolation or as a combination, amino acid (AA) supplementation has the potential to increase endurance performance among other benefits. L-Arginine (L-Arg) and L-Citrulline (L-Cit) are two AAs proposed to increase endothelial nitric oxide (NO) synthesis, with potential additional physiological benefits, and therefore may contribute to enhanced performance outcomes such as increased power output, or time to exhaustion. However, the appropriate dose for promoting physiological and performance benefits of these AAs, and their potential synergistic effects remains to be determined. Therefore, the aim of this review was to evaluate the varied concentrations used in the current literature, assess the effects of L-Arg and L-Cit in combination on physiological responses and endurance performance, and consider if there is a fundamental basis for providing these supplements in the form of a beverage. A total of six studies were considered eligible for the review which utilized a range of 3–8 g of the AA constituents. The findings support the notion that supplementing with a combination of L-Arg and L-Cit may increase NO production, enhance vasodilation, and therefore increase performance capacity in athletes. A beverage as a carrier for the two AAs is worth considering; however, there remains limited research assessing these outcomes across a consistent range of concentrations in order to see their full potential.

The Relationship Between Work-Life Balance (WLB) and Firm Performance

2017 ◽  
pp. 402-411
Author(s):  
Choi Sang Long
Keyword(s):  
Firm Performance ◽  
Organizational Performance ◽  
Management Practices ◽  
Longitudinal Research ◽  
Synergistic Effects ◽  
Performance Outcomes ◽  
Favorable Effect ◽  
And Performance ◽  
The Cost ◽  
The Relationship

It is paramount that firms accurately assess the cost-effectiveness of WLB policies as initiatives to conduct such policies involve cost. WLB policies should be considered due to synergistic effects by employing a variety of policies. The benefits are usually under-estimated while the costs over-estimated, as the latter is easier to measure. Until longitudinal research is conducted, we cannot discount the possibility that successful organizations are more likely to offer WLB practices, and that the practices themselves are not exerting any favorable effect on organizational performance. Instead, it might simply be that organizations offering WLB practices are more predisposed to engaging in high-quality management practices and that this approach usually generates a positive effect on employees and performance outcomes. Thus, we can surmise that improved firm performance is a result of effective management usually associated with the implementation of WLB policies in the workplace, and not solely because of WLB per se.

Glucose feedings and exercise in rats: glycogen use, hormone responses, and performance

1990 ◽  
Vol 69 (3) ◽  
pp. 989-994 ◽  
Author(s):  
C. A. Slentz ◽  
J. M. Davis ◽  
D. L. Settles ◽  
R. R. Pate ◽  
S. J. Settles
Keyword(s):  
Plasma Glucose ◽  
Glucose Solution ◽  
Endurance Performance ◽  
Time To Exhaustion ◽  
O2 Consumption ◽  
Exercise Time ◽  
Time Points ◽  
Hormone Responses ◽  
Glycogen Utilization ◽  
And Performance

This study compared the effects of glucose feeding and water on endurance performance, glycogen utilization, and endocrine responses to exhaustive running in rats. Forty-eight trained rats ran at approximately 70% peak O2 consumption (VO2) while receiving, via gavage, 1 ml of an 18% glucose solution or water every 30 min. Glucose- (GF) and water-fed rats (WF) were pair matched and killed at rest, at 25 or 50% of their previously determined run time to exhaustion, or at exhaustion. Run times to exhaustion were 4.6 +/- 1.0 and 3.0 +/- 0.9 h in GF and WF rats, respectively. In WF rats, plasma glucose declined continuously from a resting value of 7.4 +/- 0.5 to 1.8 +/- 0.5 mM at exhaustion and was lower than in GF rats at all exercise time points. In GF rats, glucose was maintained at 7.4 +/- 0.5 mM for 3 h before dropping to 3.9 +/- 0.6 mM at exhaustion. In both groups, liver and muscle glycogen decreased dramatically during the 1st h and changed only slightly thereafter. During the 3rd h, glycogen levels were maintained in GF rats but continued to decrease in WF rats (P less than 0.05). Insulin decreased during exercise and was not significantly different between groups. Glucagon, epinephrine, norepinephrine, and corticosterone increased to a greater extent in WF than in GF rats during the first 3 h of exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Solid, Gel, and Liquid Carbohydrate Format Effects on Gut Comfort and Performance

2017 ◽  
Vol 27 (3) ◽  
pp. 247-254 ◽  
Author(s):  
Mathilde Guillochon ◽  
David S. Rowlands
Keyword(s):  
Peak Power ◽  
Perceived Exertion ◽  
Endurance Performance ◽  
Cycling Performance ◽  
Performance Outcomes ◽  
Double Blind ◽  
Fluid Ingestion ◽  
Comparable Performance ◽  
And Performance ◽  
Format Effects

Carbohydrate sports drinks produce worthwhile benefits to endurance performance compared with noncaloric controls. However, athletes now consume carbohydrate in a range of formats, including gels and bars, but the comparable performance outcomes are unknown. Therefore, the aim of this study was to establish the relative effects of drink, gel, bar, and mixed carbohydrate formats on intense cycling performance. In a treatmentapparent randomized crossover design, 12 well-trained male cyclists completed 4 trials comprising a 140-min race simulation, followed by a double-blind slow-ramp to exhaustion (0.333 W·s-1). Carbohydrate comprising fructose and maltodextrin was ingested every 20 min via commercial drink, gel, bar, or mix of all 3, providing 80 g carbohydrate·h-1. Fluid ingestion was 705 ml·h-1. Exertion, fatigue, and gastrointestinal discomfort were measured with VAS. Performance peak power (SD) was 370 (41), 376 (37), 362 (51) and 368 W (54) for drink, gels, bars, and mix respectively. The reduction in power (-3.9%; 90%CI ±4.3) following bar ingestion vs. gel was likely substantial (likelihood harm 81.2%; benefit 0.8%), but no clear differences between drinks, gels, and the mix were evident. Bars also produced small-moderate standardized increases in nausea, stomach fullness, abdominal cramps, and perceived exertion, relative to gels (likelihood harm 95–99.5%; benefit <0.01%) and drink (75–95%; <0.01%); mix also increased nausea relative to gels (95%; <0.01%). Relative to a gel, carbohydrate bar ingestion reduced peak power, gut comfort, and ease of exertion; furthermore, no clear difference relative to drink suggests bars alone are the less favorable exogenous-carbohydrate energy source for intense endurance performance.

The school competency contingency of worth as a mediator between performance-oriented achievement goals and performance outcomes

2003 ◽  
Author(s):  
David Buck ◽  
Noelle Liwski ◽  
Connie Wolfe ◽  
Maxx Somers ◽  
Kati Knight ◽  
...  
Keyword(s):  
Achievement Goals ◽  
Performance Outcomes ◽  
And Performance

https://imsciences.edu.pk/files/journals/vol12_2/New%201%20MA.864.pdf

2020 ◽  
Vol 12 (2) ◽  
pp. 19-50 ◽  
Author(s):  
Muhammad Siddique ◽  
Shandana Shoaib ◽  
Zahoor Jan
Keyword(s):  
Organizational Performance ◽  
Structural Equation ◽  
High Performance ◽  
Service Sector ◽  
Performance Outcomes ◽  
Theory And Practice ◽  
Relational Coordination ◽  
Multiple Sources ◽  
And Performance ◽  
High Level

A key aspect of work processes in service sector firms is the interconnection between tasks and performance. Relational coordination can play an important role in addressing the issues of coordinating organizational activities due to high level of interdependence complexity in service sector firms. Research has primarily supported the aspect that well devised high performance work systems (HPWS) can intensify organizational performance. There is a growing debate, however, with regard to understanding the “mechanism” linking HPWS and performance outcomes. Using relational coordination theory, this study examines a model that examine the effects of subsets of HPWS, such as motivation, skills and opportunity enhancing HR practices on relational coordination among employees working in reciprocal interdependent job settings. Data were gathered from multiple sources including managers and employees at individual, functional and unit levels to know their understanding in relation to HPWS and relational coordination (RC) in 218 bank branches in Pakistan. Data analysis via structural equation modelling, results suggest that HPWS predicted RC among officers at the unit level. The findings of the study have contributions to both, theory and practice.

scholarly journals Jasmonates and Plant Salt Stress: Molecular Players, Physiological Effects, and Improving Tolerance by Using Genome-Associated Tools

2021 ◽  
Vol 22 (6) ◽  
pp. 3082
Author(s):  
Celia Delgado ◽  
Freddy Mora-Poblete ◽  
Sunny Ahmar ◽  
Jen-Tsung Chen ◽  
Carlos R. Figueroa
Keyword(s):  
Salt Stress ◽  
Abiotic Stresses ◽  
Synergistic Effects ◽  
Antioxidant Response ◽  
Crop Productivity ◽  
Point Of View ◽  
Physiological Effects ◽  
Crop Tolerance ◽  
Molecular Components ◽  
Ja Signaling

Soil salinity is one of the most limiting stresses for crop productivity and quality worldwide. In this sense, jasmonates (JAs) have emerged as phytohormones that play essential roles in mediating plant response to abiotic stresses, including salt stress. Here, we reviewed the mechanisms underlying the activation and response of the JA-biosynthesis and JA-signaling pathways under saline conditions in Arabidopsis and several crops. In this sense, molecular components of JA-signaling such as MYC2 transcription factor and JASMONATE ZIM-DOMAIN (JAZ) repressors are key players for the JA-associated response. Moreover, we review the antagonist and synergistic effects between JA and other hormones such as abscisic acid (ABA). From an applied point of view, several reports have shown that exogenous JA applications increase the antioxidant response in plants to alleviate salt stress. Finally, we discuss the latest advances in genomic techniques for the improvement of crop tolerance to salt stress with a focus on jasmonates.

scholarly journals Relating Competitive Golfers’ Perceived Emotions and Performance

2021 ◽  
pp. 003151252110059
Author(s):  
Erik Lundkvist ◽  
Henrik Gustafsson ◽  
Gunilla Björklund ◽  
Paul Davis ◽  
Andreas Ivarsson
Keyword(s):  
Perceived Control ◽  
Performance Outcomes ◽  
Skill Level ◽  
Complex Nature ◽  
Moderating Effects ◽  
Dynamic Relationship ◽  
And Performance ◽  
Player Skill ◽  
Task Oriented ◽  
The Relationship

The present study examined relationships between golfers’ self-perceived emotions (e.g., irritability, nervousness, tension), task-oriented coping, perceived control, and performance during a golf competition. We implemented a process-oriented golf analysis in which competitors rated these variables hole-by-hole in a competitive golf round. Within a two-level Bayesian multivariate autoregressive model, we showed that (a) within persons, emotions and task-oriented coping were reactions that stemmed from performance on the previous hole; and (b) between persons, player skill level predicted both better scores and the ability to limit the influence of negative affect on performance. These findings highlight the complex nature of the relationship between emotions and performance. Future studies might use a similarly ecologically valid research design to more precisely measure aspects of time and potentially moderating effects of player skill level and personality. An increased understanding of the dynamic relationship between emotions and performance can promote the development of effective psychological interventions for optimal performance outcomes.

Differential expression of α2D-adrenoceptor and eNOS in aortas from early and later stages of diabetes in Goto-Kakizaki rats

2004 ◽  
Vol 287 (1) ◽  
pp. H135-H148 ◽  
Author(s):  
Tsuneo Kobayashi ◽  
Takayuki Matsumoto ◽  
Kazuyuki Ooishi ◽  
Katsuo Kamata
Keyword(s):  
Vascular Reactivity ◽  
Matched Control ◽  
Early Stage ◽  
Vascular Dysfunction ◽  
Spontaneous Diabetes ◽  
Relaxation Response ◽  
No Production ◽  
Gk Rats ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

The aim of the present study was to compare vascular dysfunction between the early (12 wk old) and later (36 wk old) stages of spontaneous diabetes in Goto-Kakizaki (GK) rats. We also evaluated the aortic expression of the α2D-adrenoceptor and endothelial nitric oxide synthase (eNOS). Vascular reactivity was assessed in thoracic aortas from age-matched control rats and 12- and 36-wk GK rats. Using RT-PCR and immunoblots, we also examined the changes in expression of the α2D-adrenoceptor and eNOS. In aortas from GK rats (vs. those from age-matched control rats): 1) the relaxation response to ACh was enhanced at 12 wk but decreased at 36 wk; 2) the relaxation response to sodium nitroprusside was decreased at both 12 and 36 wk, 3) norepinephrine (NE)-induced contractility was decreased at 12 wk but not at 36 wk, 4) the expressions of α1B- and α1D-adrenoceptors were unaffected, whereas those of α2D-adrenoceptor and eNOS mRNAs were increased at both 12 and 36 wk; and 5) NE- and ACh-stimulated NOx (nitrite and nitrate) levels were increased at 12 wk, although at 36 wk ACh-stimulated NOx was lower, whereas NE-stimulated NOx showed no change. These results clearly demonstrate that enhanced ACh-induced relaxation and impaired NE-induced contraction, due to NO overproduction via eNOS and increased α2D-adrenoceptor expression, occur in early-stage GK rats and that the impaired ACh-induced relaxation in later-stage GK rats is due to reductions in both NO production and NO responsiveness (but not in eNOS expression).

Neuregulin-1 Compensates for Endothelial Nitric Oxide Synthase Deficiency

2021 ◽  
Author(s):  
Hadis Shakeri ◽  
Jente R.A. Boen ◽  
Sofie De Moudt ◽  
Jhana O. Hendrickx ◽  
Arthur J.A. Leloup ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Cardiac Fibrosis ◽  
Separate Experiment ◽  
No Production ◽  
Ang Ii ◽  
Wild Type ◽  
Paracrine Factor ◽  
Renal Hypertrophy ◽  
Neuregulin 1 ◽  
Endothelial Nitric Oxide

Endothelial cells (ECs) secrete different paracrine signals that modulate the function of adjacent cells; two examples of these paracrine signals are nitric oxide (NO) and neuregulin-1 (NRG1), a cardioprotective growth factor. Currently, it is undetermined whether one paracrine factor can compensate for the loss of another. Herein, we hypothesized that NRG1 can compensate for endothelial NO synthase (eNOS) deficiency. Methods. We characterized eNOS null and wild type (WT) mice by cardiac ultrasound and histology and we determined circulating NRG1 levels. In a separate experiment, 8 groups of mice were divided into 4 groups of eNOS null mice and wild type (WT) mice; half of the mice received angiotensin II (Ang II) to induce a more severe phenotype. Mice were randomized to daily injections with NRG1 or vehicle for 28 days. Results. eNOS deficiency increased NRG1 plasma levels, indicating that ECs increase their NRG1 expression when NO production is deleted. eNOS deficiency also increased blood pressure, lowered heart rate, induced cardiac fibrosis, and affected diastolic function. In eNOS null mice, Ang II administration increased cardiac fibrosis, but also induced cardiac hypertrophy and renal fibrosis. NRG1 administration prevented the cardiac and renal hypertrophy and fibrosis caused by Ang II infusion and eNOS deficiency. Moreover, Nrg1 expression in the myocardium is shown to be regulated by miR-134. Conclusion. This study indicates that administration of endothelium-derived NRG1 can compensate for eNOS deficiency in the heart and kidneys.

scholarly journals Effects of Feeding Time on Markers of Muscle Metabolic Flexibility Following Acute Aerobic Exercise in Trained Mice Undergoing Time Restricted Feeding

Nutrients ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1717
Author(s):  
Aaron Persinger ◽  
Matthew Butawan ◽  
Martina Faietti ◽  
Ashley Pryke ◽  
Kyley Rose ◽  
...  
Keyword(s):  
Exercise Training ◽  
Performance Outcomes ◽  
Metabolic Flexibility ◽  
Feeding Time ◽  
Restricted Feeding ◽  
Physically Active ◽  
Impact Performance ◽  
Before And After ◽  
And Performance ◽  
Access To Food

Time-restricted feeding (TRF) is becoming a popular way of eating in physically active populations, despite a lack of research on metabolic and performance outcomes as they relate to the timing of food consumption in relation to the time of exercise. The purpose of this study was to determine if the timing of feeding/fasting after exercise training differently affects muscle metabolic flexibility and response to an acute bout of exercise. Male C57BL/6 mice were randomized to one of three groups for 8 weeks. The control had ad libitum access to food before and after exercise training. TRF-immediate had immediate access to food for 6 h following exercise training and the TRF-delayed group had access to food 5-h post exercise for 6 h. The timing of fasting did not impact performance in a run to fatigue despite TRF groups having lower hindlimb muscle mass. TRF-delayed had lower levels of muscle HSL mRNA expression and lower levels of PGC-1α expression but displayed no changes in electron transport chain enzymes. These results suggest that in young populations consuming a healthy diet and exercising, the timing of fasting may not substantially impact metabolic flexibility and running performance.

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