***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: Blood flow restriction ( BFR ) training stimulates muscle size and strength by increasing muscle activation , accumulation of metabolites and muscle swelling . This method has been used in different population s , but no studies have evaluated the effects of training on muscle power and submaximal strength ( SS ) in accounted for the menstrual cycle . The aim of this study was to analyse the effect of strength training ( ST ) with BFR on the muscle power and SS of upper and lower limbs in eumenorrheic women . Forty untrained women ( 18–40 years ) were divided r and omly and proportionally into four groups : ( i ) high‐intensity ST at 80 % of 1RM ( HI ) , ( ii ) low‐intensity ST at 20 % of 1RM combined with partial blood flow restriction ( LI + BFR ) , ( iii ) low‐intensity ST at 20 % of 1RM ( LI ) and d ) control group ( CG ) . Each training group performed eight training sessions . Tests with a medicine ball ( MB ) , horizontal jump ( HJ ) , vertical jump ( VJ ) , biceps curls ( BC ) and knee extension ( KE ) were performed during the 1st day follicular phase ( FP ) , 14th day ( ovulatory phase ) and 26–28th days ( luteal phase ) of the menstrual cycle . There was no significant difference among groups in terms of the MB , HJ , VJ or BC results at any time point ( P>0·05 ) . SS in the KE exercise was significantly greater in the LI + BFR group compared to the CG group ( P = 0·014 ) during the LP . Therefore , ST with BFR does not appear to improve the power of upper and lower limbs and may be an alternative to improve the SS of lower limbs of eumenorrheic women Abstract Vieira , PJC , Chiappa , GR , Umpierre , D , Stein , R , and Ribeiro , JP . Hemodynamic responses to resistance exercise with restricted blood flow in young and older men . J Strength Cond Res 27(8 ) : 2288–2294 , 2013—Exercise with blood flow restriction promotes significant improvements , and it has been considered an attractive exercise strategy , especially for older individuals . However , the acute cardiovascular responses to resistance exercise with blood flow restriction ( BFR ) are not fully known . The purpose of this study was to evaluate the hemodynamic responses during resistance exercise with BFR in young and older individuals . We compared hemodynamic responses in 15 young ( 30 ± 3 years ) and 12 older ( 66 ± 7 years ) subjects  during low-intensity resistance biceps curl exercise with ( BFR-RE ) or without ( RE ) BFR in a r and om and crossover design . Heart rate ( HR ) , mean blood pressure ( MBP ) , calf blood flow ( CBF ) , and calf vascular resistance ( CVR ) were evaluated . Both groups presented similar values at baseline . Compared with RE , HR and MBP were higher during BFR-RE for both the groups , and these changes were maintained during the recovery period . In both the groups , BFR-RE elicited larger decreases in CBF and increased CVR . Both groups showed a significant increase in double product during BFR-RE . In conclusion , resistance exercise with BFR  elicits greater hemodynamic changes in healthy young and older subjects , with responses of similar magnitudes in both groups . The safety of BFR in clinical practice dem and s further study in vulnerable population AIM The purpose of this study was to compare hemodynamic responses during low-intensity resistance exercise , with ( LI-BFR ) and without ( LI ) blood flow restriction , with high-intensity resistance exercise ( HI ) . METHODS In a r and omized crossover design , 17 healthy subjects performed 3 sets ( 15 repetitions , 20 % 1RM , 45-second rest interval between sets ) of 45 ° bilateral leg press exercises for the LI-BFR and LI protocol s ; and 3 sets ( 8 repetitions ; 80 % 1RM ; 1-minute rest interval between sets ) for the HI protocol . The BFR was established using two sphygmomanometers ( 18x90 cm ) inflated to partially occlude blood flow to the femoral artery . Systolic blood pressure ( SBP ) , diastolic blood pressure ( DBP ) , heart rate ( HR ) , stroke volume ( SV ) , cardiac output ( CO ) and total peripheral resistance ( TPR ) were evaluated continuously and noninvasively by beat-to-beat measurements during each protocol . RESULTS Significantly smaller values were demonstrated during the LI-BFR session versus the HI session between the first and second sets for SBP ; during the first , second and third sets for DBP ; during the first set for HR ; during the first , second and third sets for SV ; during the first set for CO , and during the second set for TPR . Conversely , perceived exertion was significantly higher in the LI-BFR session versus the HI session . CONCLUSION The LI-BFR session was associated with significantly reduced cardiovascular responses versus the HI session , but showed higher values of subjective perceived exertion The neurocirculatory responses to exercise are exaggerated in hypertension , increasing cardiovascular risk , yet the mechanisms remain incompletely understood . The aim of this study was to examine the in vitro effectiveness of pyridoxal-5-phosphate as a purinergic ( P2 ) receptor antagonist in isolated murine dorsal root ganglia ( DRG ) neurons and the in vivo contribution of P2 receptors to the neurocirculatory responses to exercise in older adults with moderately elevated systolic blood pressure ( BP ) . In vitro , pyridoxal-5-phosphate attenuated the ATP-induced increases in [Ca(2+)](i ) ( 73 ± 15 vs. 11 ± 3 nM ; P < 0.05 ) . In vivo , muscle sympathetic nerve activity ( MSNA ; peroneal microneurography ) and arterial BP ( Finometer ) were assessed during exercise pressor reflex activation ( static h and grip followed by postexercise ischemia ; PEI ) during a control trial ( normal saline ) and localized P2 receptor blockade ( pyridoxal-5-phosphate ) . Compared with normotensive adults ( 63 ± 2 yr , 117 ± 2/70 ± 2 mmHg ) , adults with moderately elevated systolic BP ( 65 ± 1 yr , 138 ± 5/79 ± 3 mmHg ) demonstrated greater increases in MSNA and BP during h and grip and PEI . Compared with the control trial , local antagonism of P2 receptors during PEI partially attenuated MSNA ( 39 ± 4 vs. 34 ± 5 bursts/min ; P < 0.05 ) in adults with moderately elevated systolic BP . In conclusion , these data demonstrate pyridoxal-5-phosphate is an effective P2 receptor antagonist in isolated DRG neurons , which are of particular relevance to the exercise pressor reflex . Furthermore , these findings indicate that exercise pressor reflex function is exaggerated in older adults with moderately elevated systolic BP and further suggest a modest role of purinergic receptors in evoking the abnormally large reflex-mediated increases in sympathetic activity during exercise in this clinical population Abstract The purpose of this study was to analyze systolic blood pressure ( SBP ) , diastolic blood pressure ( DBP ) and the heart rate ( HR ) before , during and after training at moderate intensity ( MI , 50%-1RM ) and at low intensity with blood flow restriction ( LIBFR ) . In a r and omized controlled trial study , 14 subjects ( average age 45±9,9 years ) performed one of the exercise protocol s during two separate visits to the laboratory . SBP , DBP and HR measurements were collected prior to the start of the set and 15 , 30 , 45 and 60 minutes after knee extension exercises . Repeated measures of analysis of variance ( ANOVA ) were used to identify significant variables ( 2 x 5 ; group x time ) . The results demonstrated a significant reduction in SBP in the LIBFR group . These results provide evidence that strength training performed acutely alters hemodynamic variables . However , training with blood flow restriction is more efficient in reducing blood pressure in hypertensive individuals than training with moderate intensity We investigated the hemodynamic and hormonal responses to a short-term low-intensity resistance exercise ( STLIRE )  with the reduction of muscle blood flow . Eleven untrained men performed bilateral leg extension exercise under the reduction of muscle blood flow of the proximal end of both legs pressure-applied by a specially design ed belt  ( a b and ing pressure of 1.3 times higher than resting systolic blood pressure , 160–180 mmHg ) , named as Kaatsu . The intensity of STLIRE was 20 % of one repetition maximum . The subjects performed 30 repetitions , and after a 20-seconds rest , they performed three sets again until exhaustion . The superficial femoral arterial blood flow and hemodynamic parameters were measured by using the ultrasound and impedance cardiography  . Serum concentrations of growth hormone ( GH ) , vascular endothelial growth factor ( VEGF ) , noradrenaline ( NE ) , insulin-like growth factor (IGF)-1 , ghrelin , and lactate were also measured . Under the conditions with Kaatsu , the arterial flow was reduced to about 30 % of the control . STLIRE with Kaatsu significantly increased GH ( 0.11±0.03 to 8.6±1.1 ng/ml , P < 0.01 ) , IGF-1 ( 210±40 to 236±56 ng/ml , P < 0.01 ) , and VEGF ( 41±13 to 103±38 pg/ml , P < 0.05 ) . The increase in GH was related to neither NE nor lactate , but the increase in VEGF was related to that in lactate ( r = 0.57 , P < 0.05 ) . Ghrelin did not change during the exercise . The maximal heart rate ( HR ) and blood pressure ( BP ) in STLIRE with Kaatsu were higher than that without Kaatsu . Stroke volume ( SV ) was lower due to the decrease of the venous return by Kaatsu , but , total peripheral resistance ( TPR ) did not change significantly . These results suggest that STLIRE with Kaatsu significantly stimulates the exercise-induced GH , IGF , and VEGF responses with the reduction of cardiac preload during exercise , which may become a unique method for rehabilitation in patients with cardiovascular diseases We examined the effects of high-intensity resistance training ( HIT ) and low-intensity blood flow-restricted ( LI-BFR ) resistance training on carotid arterial compliance . Nineteen young men were r and omly divided into HIT ( n = 9 ) or LI-BFR ( n = 10 ) groups . The HIT and LI-BFR groups performed 75 and 30 % , respectively , of one-repetition maximum ( 1-RM ) bench press exercise , 3 days per week for 6 weeks . During the training sessions , the LI-BFR group wore elastic cuffs around the most proximal region of both arms . Muscle cross-sectional area ( CSA ) , 1-RM strength , and carotid arterial compliance were measured before and 3 days after the final training session . Acute changes in systolic arterial pressure ( SAP ) , plasma endothelin-1 ( ET-1 ) , nitrite/nitrate ( NOx ) , and noradrenalin concentrations were also measured during and after a bout of training session . The training led to significant increases ( P < 0.01 ) in bench press 1-RM and arm and chest muscle CSA in the two training groups . Carotid arterial compliance decreased significantly ( P < 0.05 ) in the HIT group , but not in the LI-BFR group . There was a significant correlation ( r = −0.533 , P < 0.05 ) between the change in carotid arterial compliance and the acute change in SAP during training sessions ; however , ET-1 and NOx did not correlate with carotid arterial compliance . Our results suggest that muscle CSA and strength increased following 6 weeks of both HIT and LI-BFR training . However , carotid arterial compliance decreased in only the HIT group , and the changes were correlated with SAP elevations during exercise sessions Light-load exercise training with blood flow restriction ( BFR ) increases muscle strength and size . However , the hemodynamics of BFR exercise appear elevated compared with non-BFR exercise . This questions the suitability of BFR in special/ clinical population s. Nevertheless , hemodynamics of st and ard prescription protocol s for BFR and traditional heavy-load exercise have not been compared . We investigated the hemodynamics of two common BFR exercise methods and two traditional resistance exercises .  Twelve young males completed four unilateral elbow flexion exercise trials in a balanced , r and omized crossover design : ( a ) heavy load [ HL ; 80 % one-repetition maximum ( 1-RM ) ] ; ( b ) light load ( LL ; 20 % 1-RM ) ; and two other light-load trials with BFR applied ( c ) continuously at 80 % resting systolic blood pressure ( BFR-C ) or ( d ) intermittently at 130 % resting systolic blood pressure ( BFR-I ) . Hemodynamics were measured at baseline , during exercise , and for 60-min post-exercise . Exercising heart rate , blood pressure , cardiac output , and rate-pressure product were significantly greater for HL and BFR-I compared with LL . The magnitude of hemodynamic stress for BFR-C was between that of HL and LL . These data show reduced hemodynamics for continuous low-pressure B 
    Output:
    
Divergent results were found when comparing the LI protocol s with BFR versus LI versus high intensity ( HI ) on BP , HR and RPP .
The evidence shows that the protocol s using continuous BFR following a LIRT session apparently raise HR , BP and RPP compared with LI protocol s without BFR , although increases significantly in BP seem to exist between the HI protocol s when compared to LI protocol s. Haemodynamic changes ( HR , SBP , DBP , MBP , RPP ) promoted by LIRT with BFR do not seem to differ between ages and body segments ( upper or lower ) , although they are apparently affected by the width of the cuff and are higher with continuous BFR .
However , these changes are within the normal range , rendering this method safe and feasible for special population