Positive correlation between plasma nitrite and performance during high-intensive exercise but not oxidative stress in healthy men

Nitric Oxide ◽  
2010 ◽  
Vol 23 (2) ◽  
pp. 128-135 ◽  
Author(s):  
Ulrike Dreißigacker ◽  
Marcel Wendt ◽  
Torge Wittke ◽  
Dimitrios Tsikas ◽  
Norbert Maassen
Author(s):  
Dafnis Vidal Pérez ◽  
José Miguel Martínez-Sanz ◽  
Alberto Ferriz-Valero ◽  
Violeta Gómez-Vicente ◽  
Eva Ausó

Weightlifting is a discipline where technique and anthropometric characteristics are essential to achieve the best results in competitions. This study aims to analyse the relationships between body composition, limb length and barbell kinematics in the performance of weightlifters. It consists of an observational and descriptive study of 19 athletes (12 men [28.50 ± 6.37 years old; 84.58 ± 14.11 kg; 176.18 ± 6.85 cm] and 7 women [27.71 ± 6.34 years old; 64.41 ± 7.63 kg; 166.94 ± 4.11 cm]) who met the inclusion criteria. A level I anthropometrist took anthropometric measures according to the methodology of the International Society for the Advancement of Kinanthropometry (ISAK), and the measurement of the barbell velocity was made with the software Kinovea. In terms of body composition, both genders are within the percentage range of fat mass recommended for this sport. In female weightlifters, there is a positive correlation between foot length, maximal velocity in the Snatch (ρ = 0.775, p = 0.041), and performance indicator in the Snatch and the Clean & Jerk (ρ = 0.964, p < 0.001; ρ = 0.883, p = 0.008, respectively). In male weightlifters, a positive correlation between tibial length and average velocity of the barbell in the Snatch is observed (ρ = 0.848, p < 0.001). Muscle mass percentage correlates positively with performance indicator in both techniques (ρ = 0.634, p = 0.027; ρ = 0.720, p = 0.008). Also, the relative length of the upper limb is negatively correlated with the performance indicator (ρ = −0.602, p = 0.038). Anthropometry and body composition may facilitate skill acquisition among this sport population, contributing to increase the limited body of scientific knowledge related to weightlifting.


2011 ◽  
Vol 43 (Suppl 1) ◽  
pp. 436
Author(s):  
Tyler M. Farney ◽  
Mohammad M. Kabir ◽  
John F. Trepanowski ◽  
Robert E. Canale ◽  
Richard J. Bloomer

Nitric Oxide ◽  
2009 ◽  
Vol 20 (4) ◽  
pp. 231-237 ◽  
Author(s):  
Jason D. Allen ◽  
Elizabeth M. Miller ◽  
Earl Schwark ◽  
Jennifer L. Robbins ◽  
Brian D. Duscha ◽  
...  

Author(s):  
Anggia Sri Ryzky ◽  
Wendi Kusriandi

This study, analyzed the students’ communication performance and competence in the speaking class. This study also measured the students’ communication apprehension level and its correlation with communication performance and competence. 30 students of second year students of SMK Pariwisata Kosgoro Cirebon took part in this study. The data were gathered through questionnaire, presentation test to get the score of communication performance and interview test to get the score of communication competence. The correlation study was used to investigate the relation of each variable. The result from the students’ performance showed that 66,7% of the students scored below the school standard score (75) and 70% of the students scored below standard score in the interview test. The participants showed the highest apprehension to public speaking and the lowest apprehension to group discussion. Their level of apprehension showed that 43.3% students were in moderate level and 56,7% students were in high level of apprehension. It was also found that communication apprehension was negatively correlated with communication performance. While the result from the correlation between communication apprehension and competence showed that there was a very low positive correlation but, there was a high positive correlation between communication competence and performance.


Retos ◽  
2015 ◽  
pp. 11-14
Author(s):  
Ernesto De la Cruz Sánchez ◽  
José Pino Ortega ◽  
María Isabel Moreno Conteras ◽  
María Cañadas Alonso ◽  
Jorge Ruiz-Risueño Abab

Los micronutrientes son componentes minoritarios pero esenciales de nuestra dieta. Actualmente existe una creencia en los países occidentales desarrollada y apoyada por evidencias científicas que supone que el consumo de ciertos micronutrientes previene importantes problemas de salud. Se alude a un fenómeno conocido como estrés oxidativo, que es causa de envejecimiento y degeneración celular y que puede ser contrarrestado mediante el consumo regular de micronutrientes antioxidantes. En concreto, entre el amplio colectivo de personas que practican deporte, esta creencia está muy extendida y arraigada y las ventas de determinados productos se han disparado en las dos últimas décadas, suponiendo un gran mercado de consumo para las empresas del sector; de hecho es frecuente encontrar en la mayoría de los centros deportivos y gimnasios de nuestras ciudades algún estante en el que se exhiben para su venta complementos nutricionales que contienen productos antioxidantes que prometen mejorar la salud y el rendimiento… El presente trabajo pretende responder a la cuestión acerca de la necesidad o conveniencia de emplear suplementos nutricionales antioxidantes para mejorar la salud de las personas que practican deporte de forma regular.Abstract: Micronutrients are minority but essential components of our diet. Nowadays a belief exists in the western countries developed and supported by scientific evidences that it supposes that the consumption of certain micronutrients prevents serious health problems. One alludes to a phenomenon known as oxidative stress, that is a reason of aging and cell degeneration and that can be offset by means of the regular consumption antioxidant micronutrients. In fact, among the wide group of persons who practise sport, this belief is very widespread and deep-rooted and the sales of certain products have gone off in last two decades, supposing a great consumer market for the companies of the sector; of fact it’s frequent to find in the majority of the sports centers of our cities some shelf in which there show themselves to sale nutritional complements that contain antioxidant products that promise to improve the health and performance … the present work tries to answer to the question brings over of the need or convenience of using nutritional antioxidant supplements to improve the health of the persons who practise sport.


2021 ◽  
Vol 15 (12) ◽  
pp. 3312-3314
Author(s):  
Shagufta Khaliq ◽  
Mudassar Ali Roomi ◽  
Shaheena Naz ◽  
Komal Iqbal ◽  
Muhammad Imran Ashraf ◽  
...  

Aim: To determine and compare gamma glutamyl transferase (GGT) and fibrinogen among obese males with and without obstructive sleep apnea (OSA). Second objective was to investigate correlation between blood pressure and GGT. Methodology: Sixty-four obese males aged 20-45 years with BMI > 25kg/m2 were included by convenience sampling. The study was conducted, after obtaining ethical approval from IRB, at the Department of Physiology, Post Graduate Medical Institute, Lahore from August 2014 to May 2015. Participants having acute or chronic inflammatory conditions were excluded. Participants were screened for OSA by Berlin and STOP BANG questionnaires. Diagnosis of OSA was made by overnight portable pulse oximetry. The participants were divided into two groups. Group I had 32 obese males with OSA. Group II contained 32 obese males without OSA. After an overnight fasting of 10-12 hours blood samples were drawn. Serum fibrinogen and GGT were measured by spectrophotometer. The data was analyzed using SPSS-22. Quantitative variables were compared between the two groups by Mann-Whitney U test. Spearman correlation was used to correlate blood pressure and GGT among the participants. Results: Fibrinogen was significantly raised (p=0.015) in obese males with OSA. Systolic blood pressure (p=0.003), diastolic blood pressure (p=0.001) and mean arterial blood pressure (p<0.001) showed strong positive correlation with GGT in obese males with OSA. Conclusion: Proinflammatory, procoagulant and proatherogenic marker fibrinogen levels were significantly raised in obese otherwise healthy males with OSA. Oxidative stress marker GGT showed strong positive correlation with blood pressure in obese males with OSA. Keywords: Fibrinogen, gamma glutamyl transferase, inflammation, obstructive sleep apnea, oxidative stress


2011 ◽  
Vol 23 (1) ◽  
pp. 218
Author(s):  
M. Nichi ◽  
R. P. Bertolla ◽  
T. B. Soler ◽  
C. N. M. Cortada ◽  
R. M. Zuge ◽  
...  

Previous studies have indicated that semen of heat-stressed bulls shows impaired mitochondrial activity and high levels of oxidative stress, which may cause structural damage to biomolecules, DNA, lipids, carbohydrates and proteins, as well as other cellular components (Nichi et al. 2006 Theriogenology 66, 822–828). Disruption of the sperm mitochondria could have a potential damaging effect not only on an individual sperm cell but also on the surrounding cells, especially regarding the sperm membrane, possibly due to the release of a high amount of reactive oxygen species (ROS) produced in this environment (rich in electrons) that would then lead to oxidative stress. To test this hypothesis, semen samples of 11 Simmental bulls kept in tropical environments were collected during the summer months. Semen was evaluated as follows: the 3-3′ diaminobenzidine stain (DAB) as an index of mitochondrial activity, the hypo-osmotic swelling test (HOST) as an index of membrane integrity, measurement of thiobarbituric acid reactive substances (TBARS) as an index of lipid peroxidation, and measurement of the enzymatic antioxidants superoxide dismutase, catalase and glutathione peroxidase activities. For correlation analysis, the Pearson test was used (variables were transformed when necessary), and for nonparametric variables, the Spearman rank test was used. A high positive correlation was found between sperm cells with highly active mitochondria (DAB class I) and the percentage of cells with intact membrane by HOST (r = 0.93; P < 0.05), and a negative correlation between the latter and the percentage of inactive mitochondria (r = –0.91; P < 0.05), indicating that the higher the percentage of cells showing impaired mitochondrial activity, the higher the percentage of cells with damaged membrane. There was also a positive correlation between TBARS and the percentage of cells with disrupted mitochondria (r = 0.86; P < 0.05), indicating that the higher the percentage of sperm with impaired mitochondrial activity, the higher the oxidative stress. No correlation existed between the enzymatic antioxidants and any of the variables studied. The results indicate that heat stress may lead to an increase in testicular ROS levels, overcoming the seminal antioxidant protection. This, in turn, may cause damage of the mitochondria and a subsequent release of more pro-oxidative substances, and an exponential increase of oxidative stress. Understanding these mechanisms may lead to more tailored antioxidant therapies in the future. The authors thank FAPESP for the scholarship and financial support.


2020 ◽  
Vol 11 (4) ◽  
pp. 537-567 ◽  
Author(s):  
Tao Scofield Su ◽  
Chunhua Chen ◽  
Xiaoyu Cui ◽  
Chunsheng Yang ◽  
Weimo Ma

Purpose This paper aims to answer following three important but not well-answered or unanswered questions in the extant trust literatures: What is the true magnitude that trust impacts on performance? Is there any consistency among the effects of trust on performance at different levels? How does vertical distance affect the trust-performance relationship? Design/methodology/approach It captures the law between trust and performance at different levels by conducting a meta-analytic examination consisting of 238 independent empirical studies, 586 effect sizes and 110,576 independent samples. Findings It makes a periodic conclusion that trust significantly promotes performance. Specifically, trust not only has stronger positive correlation with team performance than individual and organizational performance inside organization, but also strongly facilitates organizational performance between organizations. Moreover, consistency exits in the effects of trust on performance at different levels. On one hand, trust has stronger positive correlation with performance of contextual type than performance of innovative type than performance of task type at different levels. On the other hand, promotion effect of trust on performance strengthens when the vertical distance between trustors and trustees diminishes. Additionally, three potential moderators including publication status, measurement tool and common method variance moderate the focused relation, but moderating effect is not thorough for regional culture. Moderating directions of the above four potential moderators are highly consistent. Originality/value This paper answers the three important but not well-answered or unanswered questions.


2004 ◽  
Vol 286 (6) ◽  
pp. H2113-H2117 ◽  
Author(s):  
Kevin D. Monahan ◽  
Iratxe Eskurza ◽  
Douglas R. Seals

Cardiovagal baroreflex sensitivity (BRS) declines with advancing age in healthy men. We tested the hypothesis that oxidative stress contributes mechanistically to this age-associated reduction. Eight young (23 ± 1 yrs, means ± SE) and seven older (63 ± 3) healthy men were studied. Cardiovagal BRS was assessed using the modified Oxford technique (bolus infusion of 50–100 μg sodium nitroprusside, followed 60 s later by a 100- to 150-μg bolus of phenylephrine hydrochloride) in triplicate at baseline and during acute intravenous ascorbic acid infusion. At baseline, cardiovagal BRS (slope of the linear portion of the R-R interval-systolic blood pressure relation during pharmacological changes in arterial blood pressure) was 56% lower ( P < 0.01) in older (8.3 ± 1.6 ms/mmHg) compared with young (19.0 ± 3.1 ms/mmHg) men. Ascorbic acid infusion increased plasma concentrations similarly in young (62 ± 9 vs. 1,249 ± 72 μmol/l for baseline and during ascorbic acid; P < 0.05) and older men (62 ± 4 vs. 1,022 ± 55 μmol/l; P < 0.05) without affecting baseline blood pressure, heart rate, carotid artery compliance, or the magnitude of change in systolic blood pressure in response to bolus sodium nitroprusside and phenylephrine hydrochloride infusion. Ascorbic acid (vitamin C) infusion increased cardiovagal BRS in older (Δ58 ± 16%; P < 0.01), but not younger (Δ − 4 ± 4%) men. These data provide experimental support for the concept that oxidative stress contributes mechanistically to age-associated reductions in cardiovagal BRS in healthy men.


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