***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: To verify whether there are relationships between vascular and hormonal responses to aerobic training in hypertensive persons , sedentary hypertensive patients were r and omized to an aerobic training or a callisthenic exercise group . The patients ' 24-hour blood pressure , arterial compliance , forearm blood flow , and hormonal profile were evaluated at baseline and after 3-month training protocol s. Mean maximal oxygen consumption ( VO(2 ) max ) increased by 8 % in the aerobic group ( P<.001 ) , while no change was observed in the control group . There was a decrease in insulin resistance ( homeostatic model assessment of insulin resistance , P=.039 ) and plasma cortisol ( P=.006 ) in the aerobic group only , that also demonstrated an increase in forearm blood flow ( P<.001 ) after training . No relationship was observed between change in blood pressure or change in body mass and other parameters . Aerobic training can promote a decrease in cardiovascular risk in hypertensive adults by improving vascular function and insulin resistance , despite no changes in ambulatory blood pressure after a 3-month intervention The effects of long-term aerobic exercise on endothelial function in patients with essential hypertension remain unclear . To determine whether endothelial function relating to forearm hemodynamics in these patients differs from normotensive subjects and whether endothelial function can be modified by continued physical exercise , we r and omized patients with essential hypertension into a group that engaged in 30 minutes of brisk walking 5 to 7 times weekly for 12 weeks ( n=20 ) or a group that underwent no activity modifications  ( control group , n=7 ) . Forearm blood flow was measured using strain-gauge plethysmography during reactive hyperemia to test for endothelium-dependent vasodilation and after sublingual nitroglycerin administration to test endothelium-independent vasodilation . Forearm blood flow in hypertensive patients during reactive hyperemia was significantly less than that in normotensive subjects ( n=17 ) . Increases in forearm blood flow after nitroglycerin were similar between hypertensive and normotensive subjects . Exercise lowered mean blood pressure from 115.7+/-5.3 to 110.2+/-5.1 mm Hg ( P<0.01 ) and forearm vascular resistance from 25.6+/-3.2 to 23 . 2+/-2.8 mm Hg/mL per minute per 100 mL tissue ( P<0.01 ) ; no change occurred in controls . Basal forearm blood flow , body weight , and heart rate did not differ with exercise . After 12 weeks of exercise , maximal forearm blood flow response during reactive hyperemia increased significantly , from 38.4+/-4.6 to 47.1+/-4.9 mL/min per 100 mL tissue ( P<0.05 ) ; this increase was not seen in controls . Changes in forearm blood flow after sublingual nitroglycerin administration were similar before and after 12 weeks of exercise . Intra-arterial infusion of the nitric oxide synthase inhibitor NG-monomethyl-L-arginine abolished the enhancement of reactive hyperemia induced by 12 weeks of exercise . These findings suggest that through increased release of nitric oxide , continued physical exercise alleviates impairment of reactive hyperemia in patients with essential hypertension After a general clinical observation period of over 4 weeks , 20 essential hypertensive subjects ( Japanese ) were r and omly divided into two groups . One group ( n = 10 ; 4 men and 6 women ; 51.4 + /- 2.8 years of age ) agreed to physical training using bicycle ergometer exercise with the intensity at blood lactate threshold for 60 minutes three times a week for 10 weeks , while the other group ( n = 10 ; 4 men and 6 women ; 51.0 + /- 2.9 years of age ) did no particular physical training and was followed once a week as the control . Changes in blood pressure , hemodynamics , and humoral factors of the exercised group were compared with values in the controls . The following significant changes were found only in the exercised group . Blood pressure was significantly ( p less than 0.01 ) reduced . Whole blood and plasma volume indices were significantly reduced ( p less than 0.05 , p less than 0.01 , respectively ) . The change in ratio of serum sodium to potassium positively correlated with the change in systolic blood pressure ( r = 0.76 , p less than 0.02 ) . Plasma norepinephrine concentrations both at rest and at the workload of blood lactate threshold during grade d exercise tests were significantly reduced ( p less than 0.05 , p less than 0.02 respectively ) after 10 weeks of exercise training . The change in the resting level of plasma norepinephrine positively correlated with that in the mean blood pressure . No such changes were observed in the control group . In both groups , body weight and urinary sodium excretion showed no statistically significant changes . ( ABSTRACT TRUNCATED AT 250 WORDS Age-related reductions in basal limb blood flow and vascular conductance are associated with the metabolic syndrome , functional impairments , and osteoporosis . We tested the hypothesis that a strength training program would increase basal femoral blood flow in aging adults . Twenty-six sedentary but healthy middle-aged and older subjects were r and omly assigned to either a whole body strength training intervention group ( 52 + /- 2 yr , 3 men , 10 women ) who underwent three supervised resistance training sessions per week for 13 wk or a control group ( 53 + /- 2 yr , 4 men , 9 women ) who participated in a supervised stretching program .  At baseline , there were no significant differences in blood pressure , cardiac output , basal femoral blood flow ( via Doppler ultrasound ) , vascular conductance , and vascular resistance between the two groups . The strength training group increased maximal strength in all the major muscle groups tested ( P < 0.05 ) . Whole body lean body mass increased ( P < 0.05 ) with strength training , but leg fat-free mass did not . Basal femoral blood flow and vascular conductance increased by 55 - 60 % after strength training ( both P < 0.05 ) . No such changes were observed in the control group . In both groups , there were no significant changes in brachial blood pressure , plasma endothelin-1 and angiotensin II concentrations , femoral artery wall thickness , cardiac output , and systemic vascular resistance . Our results indicate that short-term strength training increases basal femoral blood flow and vascular conductance in healthy middle-aged and older adults Background Contrary to aerobic exercise , strength training ( ST ) is associated with decreased  central arterial compliance in young men . It is unknown whether ST , with or without concurrent endurance training , would have a similar effect in older adults with reduced baseline arterial compliance . Objective The primary aim of this study was to determine the effect of a ST program on central arterial compliance in middle-aged and older adults . Design R and omized , controlled intervention study in which 37 healthy , sedentary men and women ( 52 ± 2 years ) performed 13 weeks of ST ( n = 13 ) , ST + aerobic exercise ( n = 12 ) or stretching exercises as a control group ( n = 12 ) . Methods Participants were rigorously screened for cardiovascular disease and underwent pre-post testing for carotid arterial compliance ( via simultaneous ultrasound and applanation tonometry ) , carotid-femoral pulse wave velocity , plasma endothelin-1 and angiotensin II concentrations and carotid artery vasoreactivity ( cold pressor test ) . Results ST performed alone , or in conjunction with aerobic exercise , improved maximal muscle strength and increased total lean body mass ( both P [ 0.01 ) . No significant changes were observed in carotid artery compliance or carotid-femoral pulse wave velocity  following ST or ST + aerobic exercise . Carotid artery compliance increased significantly ( 23 % ) following stretching which may be attributed to a reduction in carotid pulse pressure . No significant changes were observed in plasma vasoconstrictor hormones or carotid artery vasoreactivity following the interventions . Conclusion Thirteen weeks of moderate ST two or three times per week does not reduce central arterial compliance in middle-aged and older adults The effects of four levels of activity on heart rate , blood pressure , cardiac index , total peripheral resistance index ( TPRI ) , norepinephrine ( NE ) spillover rate , insulin sensitivity , and levels of lipids and some hormones were studied in 12 normal subjects . The r and omized periods were ( 1 ) 4 weeks of below-sedentary activity , ( 2 ) 4 weeks of sedentary activity , ( 3 ) 4 weeks of 40 min of bicycling three times per week , and ( 4 ) 4 weeks of similar bicycling seven times per week . Exercise three times per week reduced resting blood pressure by 10/7 mm Hg ( p less than .01 ) and it was reduced by 12/7 mm Hg after exercise seven times per week ( both p less than .01 ) . This was associated with reduction in TPRI , an increase in cardiac index , and cardiac slowing . At the highest level of activity , NE spillover rate , an index of sympathetic activity , fell to 35 % of the sedentary value ( p less than .001 ) in eight of 10 subjects . In two other subjects NE spillover rate rose , although blood pressure and TPRI were reduced . Metabolic changes included lowering of total cholesterol , but high-density lipoprotein level was unchanged . Insulin sensitivity rose by 27 % after exercise three times per week , but declined to sedentary levels with seven times per week exercise .  Maximum oxygen uptake increased linearly with activity . Exercise performed three times per week lowers blood pressure and should reduce cardiovascular risk . The same exercise seven times per week enhances physical performance with little further reduction in cardiovascular risk factors .  Exercise is potentially a major nonpharmacologic method of lowering blood pressure Central arterial compliance plays an important role in the functional abilities of the vasculature . Two active tripeptides , valine-proline-proline and isoleucine-proline-proline , were isolated from sour milk and were referred to as lactotripeptides ( LTP ) . Because LTP appears to act as an angiotensin-converting enzyme inhibitor , it is plausible to hypothesize that LTP improves arterial compliance . We determined the effects of LTP ingestion alone or in combination with regular aerobic exercise on arterial compliance .  A total of 55 postmenopausal women ( 50 - 65 yr old ) were r and omly divided into four groups : placebo , LTP , exercise and placebo ( Ex + placebo ) , or exercise and LTP ( Ex + LTP ) . LTP or placebo was administered orally for 8 wk . The exercise groups completed an 8-wk moderate aerobic exercise intervention . There were no differences in baseline arterial compliance and most other key dependent variables among the groups . Carotid arterial compliance increased significantly in the LTP ( 0.93 + or - 0.07 vs. 0.99 + or - 0.08 mm(2)/mmHg x 10(-1 ) ) , Ex + placebo ( 0.92 + or - 0.04 vs. 1.00 + or - 0.05 mm(2)/mmHg x 10(-1 ) ) , and Ex + LTP groups ( 0.86 + or - 0.06 vs. 1.00 + or - 0.06 mm(2)/mmHg x 10(-1 ) ) , whereas no such changes were observed in the placebo control group ( 0.86 + or - 0.06 vs. 0.85 + or - 0.07 mm(2)/mmHg x 10(-1 ) ) . The magnitude of increases in carotid arterial compliance was significantly greater in the Ex + LTP group ( 19 + or - 4 % ) than in other groups . The improvements in arterial compliance with LTP were associated with the corresponding reductions in arterial blood pressure and plasma angiotensin II concentrations . We concluded that LTP ingestion improves carotid arterial compliance and that the combination of LTP ingestion and regular exercise is additive and synergistic in improving arterial compliance in postmenopausal women Objective : The role of renal dopamine in the early depressor effect of exercise was evaluated in hypertensives . Methods : After a general clinical observation period of 4 weeks , 29 essential hypertensives were divided into two groups . The exercise group ( n = 16 ) underwent blood lactate threshold exercise using a cycle ergometer for 60 min three times a week for 4 weeks . Results : In the non-exercise group ( n = 13 ) , blood pressure ( BP ) and humoral variables did not change significantly ( from 150 ± 3/93 ± 2 to 145 ± 2/94 ± 1 mm Hg ) . In the exercise group ( n = 16 ) , resting BP was significantly reduced from 158 ± 2/92 ± 2 at week 0 to 145 ± 3/85 ± 3 mm Hg at week 4 . The increase in urinary free dopamine excretion ( from 248 ± 14 to 276 ± 24 ng/mg Cr ) at week 4 was significantly higher than that in the non-exercise group ( from 220 ± 31 to 196 ± 27 ng/mg Cr ) . In the exercise group , urinary kallikrein activity also increased significantly from 173.0 ± 35.4 at week 0 to 320.3 ±  
    Output:
    
To conclude , although we observed a significant reduction in plasma renin activity  following exercise training this was not related to the observed blood pressure reduction .