ISRN Physiology最新文献

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Effects of Nitrate Supplementation on Cardiovascular and Autonomic Reactivity in African-American Females. 补充硝酸盐对非裔美国女性心血管和自主神经反应性的影响。

ISRN Physiology Pub Date : 2014-02-23 DOI: 10.1155/2014/676235

Vernon Bond, Bryan H Curry, R George Adams, M Sadegh Asadi, Kimani A Stancil, Richard M Millis, Georges E Haddad

{"title":"Effects of Nitrate Supplementation on Cardiovascular and Autonomic Reactivity in African-American Females.","authors":"Vernon Bond, Bryan H Curry, R George Adams, M Sadegh Asadi, Kimani A Stancil, Richard M Millis, Georges E Haddad","doi":"10.1155/2014/676235","DOIUrl":"https://doi.org/10.1155/2014/676235","url":null,"abstract":"Previous studies have shown that beetroot juice (BJ) decreases systolic blood pressure (SBP) and oxygen demand. This study tests the hypothesis that a beetroot juice (BJ) treatment increases heart rate variability (HRV) measured by the average standard deviation of normal-normal electrocardiogram RR intervals (SDNN) and the low frequency (LF), mainly sympathetic, fast Fourier transform spectral index of HRV. The subjects were 13 healthy young adult African-American females. Placebo control orange juice (OJ) and BJ treatments were given on separate days. Blood nitric oxide [NO], SBP and RR intervals were measured at rest and at constant workloads set to 40% and 80% of the predetermined VO2peak. Two hours after ingestion the BJ treatment increased [NO] and decreased SBP. BJ also increased SDNN at rest and at the 40% VO2peak workload, without significant effects on LF. SDNN was significantly greater after the BJ than after the OJ treatment, across the two physical activity conditions and SDNN was (negatively) correlated with SBP. These results suggest that BJ decreases SBP and increases HRV at rest and during aerobic exercise. Similar results in subjects with prehypertension or hypertension could translate to a dietary nitrate treatment for hypertension.","PeriodicalId":89957,"journal":{"name":"ISRN Physiology","volume":"2014 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2014-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/676235","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32817477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 33

Neurophysiological Basis of Sleep's Function on Memory and Cognition. 睡眠对记忆和认知功能的神经生理学基础

ISRN Physiology Pub Date : 2013-01-01 DOI: 10.1155/2013/619319

Rebecca M C Spencer

引用次数: 0

Oxygen Consumption at 30 W of Exercise Is Surrogate for Peak Oxygen Consumption in Evaluation of Cardiorespiratory Fitness in Young-Adult African-American Females. 在评价非裔美国青年女性心肺健康时，30w运动时的耗氧量代替峰值耗氧量。

ISRN Physiology Pub Date : 2013-01-01 DOI: 10.1155/2013/756276

Richard M Millis, Vernon Bond, M Sadegh Asadi, Georges E Haddad, Richard G Adams

{"title":"Oxygen Consumption at 30 W of Exercise Is Surrogate for Peak Oxygen Consumption in Evaluation of Cardiorespiratory Fitness in Young-Adult African-American Females.","authors":"Richard M Millis, Vernon Bond, M Sadegh Asadi, Georges E Haddad, Richard G Adams","doi":"10.1155/2013/756276","DOIUrl":"https://doi.org/10.1155/2013/756276","url":null,"abstract":"Body mass index (BMI) is negatively correlated with cardiorespiratory fitness, measured by maximal or peak oxygen consumption (VO2peak). VO2peak measurements require heavy aerobic exercise to near exhaustion which increases the potential for adverse cardiovascular events. This study tests the hypothesis that VO2 measured at a fixed submaximal workload of 30 W is a surrogate for VO2peak. We studied 42 normotensive African-American female university students, 18-25 years of age. We measured VO2peak, blood pressure, and VO2 at a 30 W exercise workload and computed BMI. We found significant negative correlations between BMI and VO2peak (r = -0.41, P < 0.01) and between BMI and VO2 at 30 W (r = -0.53, P < 0.001). Compared to VO2peak, VO2 at 30 W increased the significance of the negative correlation with BMI. The heart rate-systolic pressure product at 30 W was positively correlated with BMI (r = 0.36, P < 0.01) and negatively correlated with VO2peak (r = -0.38, P < 0.001). The positive correlation between BMI and the heart rate-systolic pressure product and the greater negative correlation between VO2 and BMI at 30 W of exercise than that at exercise to fatigue suggest that normalized measurements of VO2 at the fixed exercise workload of 30 W could be useful surrogates for measurements of VO2peak.","PeriodicalId":89957,"journal":{"name":"ISRN Physiology","volume":"2013 ","pages":"756276"},"PeriodicalIF":0.0,"publicationDate":"2013-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2013/756276","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32083862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0