Influence of population and exercise protocol characteristics on hemodynamic determinants of post-aerobic exercise hypotension

Due to differences in study populations and protocols, the hemodynamic determinants of post-aerobic exercise hypotension (PAEH) are controversial. This review analyzed the factors that might influence PAEH hemodynamic determinants, through a search on PubMed using the following key words: “postexercise” or “post-exercise” combined with “hypotension”, “blood pressure”, “cardiac output”, and “peripheral vascular resistance”, and “aerobic exercise” combined only with “blood pressure”. Forty-seven studies were selected, and the following characteristics were analyzed: age, gender, training status, body mass index status, blood pressure status, exercise intensity, duration and mode (continuous or interval), time of day, and recovery position. Data analysis showed that 1) most postexercise hypotension cases are due to a reduction in systemic vascular resistance; 2) age, body mass index, and blood pressure status influence postexercise hemodynamics, favoring cardiac output decrease in elderly, overweight, and hypertensive subjects; 3) gender and training status do not have an isolated influence; 4) exercise duration, intensity, and mode also do not affect postexercise hemodynamics; 5) time of day might have an influence, but more data are needed; and 6) recovery in the supine position facilitates systemic vascular resistance decrease. In conclusion, many factors may influence postexercise hypotension hemodynamics, and future studies should directly address these specific influences because different combinations may explain the observed variability in postexercise hemodynamic studies

Influence of disinfection with peracetic acid and hypochlorite in dimensional alterations of casts obtained from addition silicone and polyether impressions

Made available in DSpace on 2019-09-12T16:26:12Z (GMT). No. of bitstreams: 0 Previous issue date: 2013Dental impressions disinfection is important to reduce the risk of cross contamination but this process may produce dimensional distortions. Peracetic acid is a disinfectant agent with several favorable characteristics yet underutilized in Dentistry. The aim of this paper is to compare the dimensional stability of casts obtained from addition silicone and polyether impressions that were immersed for 10 minutes in a solution of 0.2% peracetic acid or 1% sodium hypochlorite. Sixty samples in type IV gypsum were produced after a master cast that simulated a full crown preparation of a maxillary premolar. Samples were divided in 6 groups (n = 10) according to the impression material and disinfection agent: Group AC - addition silicone control (without disinfectant); Group APA - addition silicone + 0.2% peracetic acid; Group AH - addition silicone + 1% sodium hypochlorite; Group PC - polyether control (without disinfectant); Group PPA - polyether + 0.2% peracetic acid; Group PH - polyether + 1% sodium hypochlorite. Cast height, base and top diameter were measured and a mean value was obtained for each sample and group all data was statistically analyzed (ANOVA, p < 0.05). There was not a significant statistical difference between addition silicone and polyether impressions regardless of the disinfectant materials. It can be concluded that disinfection with the proposed agents did not produce significant alterations of the impressions and the peracetic acid could be considered a reliable material to disinfect dental molds.Queiroz, D.A., Department of Dentistry, University of Vila Velha, Vila Velha, Espírito Santo, BrazilPeçanha, M.M., Department of Prosthodontics, University Federal of Espirito Santo Vitória, Espírito Santo, BrazilNeves, A.C.C., Department of Prosthodontics, University of Taubaté Taubaté, São Paulo, BrazilFrizzera, F., College of Dentistry at FAESA, Vitória, BrazilTonetto, M.R., Faculty of Dentistry, University of Cuiabá, Cuiabá, Brazilda Silva-Concílio, L.R., Department of Prosthesis, University of Taubaté, Taubaté São Paulo, Brazi

Strength and power training did not modify cardiovascular responses to aerobic exercise in elderly subjects

Resistance training increases muscle strength in older adults, decreasing the effort necessary for executing physical tasks, and reducing cardiovascular load during exercise. This hypothesis has been confirmed during strength-based activities, but not during aerobic-based activities. This study determined whether different resistance training regimens, strength training (ST, constant movement velocity) or power training (PT, concentric phase performed as fast as possible) can blunt the increase in cardiovascular load during an aerobic stimulus. Older adults (63.9 ± 0.7 years) were randomly allocated to: control (N = 11), ST (N = 13, twice a week, 70-90% 1-RM) and PT (N = 15, twice a week, 30-50% 1-RM) groups. Before and after 16 weeks, oxygen uptake (VO2), systolic blood pressure (SBP), heart rate (HR), and rate pressure product (RPP) were measured during a maximal treadmill test. Resting SBP and RPP were similarly reduced in all groups (combined data = -5.7 ± 1.2 and -5.0 ± 1.7%, respectively, P < 0.05). Maximal SBP, HR and RPP did not change. The increase in measured VO2, HR and RPP for the increment in estimated VO2 (absolute load) decreased similarly in all groups (combined data = -9.1 ± 2.6, -14.1 ± 3.9, -14.2 ± 3.0%, respectively, P < 0.05), while the increments in the cardiovascular variables for the increase in measured VO2 did not change. In elderly subjects, ST and PT did not blunt submaximal or maximal HR, SBP and RPP increases during the maximal exercise test, showing that they did not reduce cardiovascular stress during aerobic tasks

Post-resistance exercise hemodynamic and autonomic responses: comparison between normotensive and hypertensive men

To compare post-resistance exercise hypotension (PREH) and its mechanisms in normotensive and hypertensive individuals, 14 normotensives and 12 hypertensives underwent two experimental sessions: control (rest) and exercise (seven exercises, three sets, 50% of one repetition maximum). Hemodynamic and autonomic clinic measurements were taken before (Pre) and at two moments post-interventions (Post 1: between 30 and 60\u2009min; Post 2: after 7\u2009h). Ambulatory blood pressure (BP) was monitored for 24\u2009h. At Post 1, exercise decreased systolic BP similarly in normotensives and hypertensives (-8\u2009\ub1\u20092 vs -13\u2009\ub1\u20092\u2009mmHg, P\u2009>\u20090.05), whereas diastolic BP decreased more in hypertensives (-4\u2009\ub1\u20091 vs -9\u2009\ub1\u20091\u2009mmHg, P\u2009\u20090.05). After exercise, heart rate (+13\u2009\ub1\u20093 vs +13\u2009\ub1\u20092\u2009bpm) and its variability (low- to high-frequency components ratio, 1.9\u2009\ub1\u20090.4 vs +1.4\u2009\ub1\u20090.3) increased whereas stroke volume (-14\u2009\ub1\u20095 vs -11\u2009\ub1\u20095\u2009mL) decreased similarly in normotensives and hypertensives (all, P\u2009>\u20090.05). At Post 2, all variables returned to pre-intervention, and ambulatory data were similar between sessions. Thus, a session of resistance exercise promoted PREH in normotensives and hypertensives. Although this PREH was greater in hypertensives, it did not last during the ambulatory period, which limits its clinical relevance. In addition, the mechanisms of PREH were similar in hypertensives and normotensives

Captopril does not Potentiate Post-Exercise Hypotension : a Randomized Crossover Study

To evaluate whether captopril (3 750 mg/day) potentiates post-resistance exercise hypotension (PREH) in hypertensives (HT), 12 HT men received captopril and placebo for 4 weeks each in a double-blinded, randomized-crossover design. On each therapy, subjects underwent 2 sessions: Control (C - rest) and Resistance Exercise (RE - 7 exercises, 3 sets to moderate fatigue, 50% of 1 RM -repetition maximum). Measurements were taken before and after 30-60 min (Post1) and 7 h (Post2), and ambulatory blood pressure (BP) was monitored for 24 h. There were no differences in PREH characteristics and mechanisms between the placebo and captopril periods. At Post1, systolic/diastolic BP decreased significantly and similarly after RE with both therapies (Placebo=-13\ub12/-9\ub11 mmHg vs. Captopril=-12\ub12/-10\ub11 mmHg, P<0.05). RE reduced cardiac output in some subjects and systemic vascular resistance in others. Heart rate and cardiac sympathetic modulation increased, while stroke volume and baroreflex sensitivity decreased after RE (Placebo: +13\ub12 bpm, +21\ub15 nu, -11\ub15 ml, -4\ub12 ms/mmHg; Captopril: +13\ub12 bpm, +35\ub14 nu, 17\ub15 ml, -3\ub11 ms/mmHg, P<0.05). At Post2, all variables returned to pre-intervention values. Ambulatory BP was similar between the sessions. Thus, captopril did not potentiate the magnitude and duration of PREH in HT men, and it did not influence PREH mechanisms