***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: 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 OBJECTIVES The progressive age-related declines in muscle health and physical function in older adults are related to muscle size and strength . Walking with an applied blood flow restriction is an alternative to maintain muscle volume in older adults to increase the value for time spent walking . Therefore , the aim of this study was to examine the effect of adding blood flow restriction to low-intensity walking on clinical measures of physical function . DESIGN / METHODS Sedentary older men and women were r and omised to either a low-intensity blood flow restriction walking group ( BFRW ; n=10 ) , or a non-blood flow restriction walking control group ( CON ; n=9 ) . Participants were assessed at baseline , three-weeks and six-weeks for the 30second sit to st and , six-minute walk test , timed up and go  , and a modified Queen  's  College step test  . While a rating of perceived exertion ( RPE ) for training sessions at baseline , three-weeks and six-weeks . RESULTS BFRW typically result ed in a 2.5 - 4.5 fold greater improvement in performance on all measures of physical function compared with CON among these older adults . However , RPE was greater for BFRW at all time points ( for baseline , three-weeks , six-weeks : 14±0 ; 11±0 ; 11±0 ) compared with CON ( 8±0 ; 7±0 ; 8±0 ) , despite declining across the study for BFRW . CONCLUSIONS The greater improvement in physical function with blood flow restriction demonstrates how this addition can increase the quality of simple walking exercise for population s that may be contraindicated to heavy-load resistance training Abstract Br and ner , CR , and Warmington , SA . Delayed onset muscle soreness and perceived exertion after blood flow restriction exercise . J Strength Cond Res 31(11 ) : 3101–3108 , 2017—The purpose of this study was to determine the perceptual responses to resistance exercise with heavy loads ( 80 % 1 repetition maximum [ 1RM ] ) , light loads ( 20 % 1RM ) , or light loads in combination with blood flow restriction ( BFR ) . Despite the use of light loads , it has been suggested that the adoption of BFR resistance exercise may be limited because of increases in delayed onset muscle soreness ( DOMS ) and perceived exertion .  Seventeen healthy untrained males participated in this balanced , r and omized cross-over study . After 4 sets of elbow-flexion exercise , participants reported ratings of perceived exertion ( RPE ) , with DOMS also recorded for 7 days after each trial . Delayed onset muscle soreness was significantly greater for low-pressure continuous BFR ( until 48 hours postexercise ) and high-pressure intermittent BFR ( until 72 hours postexercise ) than for traditional heavy-load resistance exercise and light-load resistance exercise . In addition , RPE was higher for heavy-load resistance exercise and high-pressure intermittent BFR than for low-pressure continuous BFR , with all trials greater than light-load resistance exercise . For practitioners working with untrained participants , this study provides evidence to suggest that to minimize the perception of effort and postexercise muscle soreness associated with BFR resistance exercise , continuous low-pressure application may be more preferential than intermittent high-pressure application . Importantly , these perceptual responses are relatively short-lived ( ∼2 days ) and have previously been shown to subside after a few exercise sessions . Combined with smaller initial training volumes ( set × repetitions ) , this may limit RPE and DOMS to strengthen uptake and adherence and assist in program progression for muscle hypertrophy and gains in strength PURPOSE To examine the effects of moderate-load exercise with and without blood-flow restriction ( BFR ) on strength , power , and repeated-sprint ability , along with acute and chronic salivary hormonal parameters . METHODS Twenty male semiprofessional rugby union athletes were r and omized to a lower-body BFR intervention ( an occlusion cuff inflated to 180 mmHg worn intermittently on the proximal thighs ) or a control intervention that trained without occlusion in a crossover design . Experimental sessions were performed 3 times a week for 3 wk with 5 sets of 5 repetitions of bench press , leg squat , and pull-ups performed at 70 % of 1-repetition maximum . RESULTS Greater improvements were observed ( occlusion training vs control ) in bench press ( 5.4 ± 2.6 vs 3.3 ± 1.4 kg ) , squat ( 7.8 ± 2.1 vs 4.3 ± 1.4 kg ) , maximum sprint time ( -0.03 ± 0.03 vs -0.01 ± 0.02 s ) , and leg power ( 168 ± 105 vs 68 ± 50 W ) . Greater exercise-induced salivary testosterone ( ES 0.84 - 0.61 ) and cortisol responses ( ES 0.65 - 0.20 ) were observed after the occlusion intervention sessions compared with the nonoccluded controls ; however , the acute cortisol increases were attenuated across the training block . CONCLUSIONS Occlusion training can potentially improve the rate of strength-training gains and fatigue resistance in trained athletes , possibly allowing greater gains from lower loading that could be of benefit during high training loads , in competitive seasons , or in a rehabilitative setting . The clear improvement in bench-press strength result ing from lower-body occlusion suggests a systemic effect of BFR training OBJECTIVES To investigate the effect of blood flow restriction or normobaric hypoxic exposure combined with low-load resistant exercise ( LRE ) , on muscular strength and endurance . DESIGN A r and omised controlled trial . METHODS Well-trained netball players ( n=30 ) took part in a 5 weeks training of knee flexor and extensor muscles in which LRE ( 20 % of one repetition maximum ) was combined with ( 1 ) an occlusion pressure of approximately 230mmHg around the upper thigh ( KT , n=10 ) , ( 2 ) hypoxic air to generate blood oxyhaemoglobin levels of approximately 80 % ( HT , n=10 ) or ( 3 ) with no additional stimulus ( CT , n=10 ) . The training was of the same intensity and amount in all groups . One to five days before and after training , participants performed a series of strength and endurance tests of the lower limbs ( 3-s maximal voluntary contraction [ MVC3 ] , area under 30-s force curve [ MVC30 ] , number of repetitions at 20 % 1RM [ Reps201RM ] ) . In addition , the cross-sectional area ( CSA ) of the quadriceps and hamstrings were measured . RESULTS Relative to CT , KT and HT increased MVC3 ( 11.0±11.9 % and 15.0±13.1 % ) , MVC30 ( 10.2±9.0 % and 18.3±17.4 % ) and Reps201RM ( 28.9±23.7 % and 23.3±24.0 % , mean±90 % confidence interval ) after training . CSA increased by 6.6±4.5 % , 6.1±5.1 % and 2.9±2.7 % in the KT , HT and CT groups respectively . CONCLUSIONS LRE in conjunction with KT or HT can provide substantial improvements in muscle strength and endurance and may be useful alternatives to traditional training practice Purpose Slow-walk training combined with restricted leg muscular blood flow ( KAATSU ) produces muscle hypertrophy and strength gains in young men , which may lead to increased aerobic capacity and functional fitness . The purpose of this study was to investigate the effects of walk training combined with KAATSU on muscle size , strength , and functional ability , as well as aerobic capacity , in older participants . Methods A total of 19 active men and women , aged 60 to 78 years , were r and omized into either a KAATSU-walk training group ( n = 11 , K-walk ) or a nonexercising control group ( n = 8 , control ) . The K-walk group performed 20-minute treadmill walking ( 67 m/min ) , 5 days/wk for 6 weeks . Results Isometric ( 11 % ) and isokinetic ( 7%-16 % ) knee extension and flexion torques , muscle-bone cross-sectional area ( 5.8 % and 5.1 % for thigh and lower leg , respectively ) , as well as ultrasound-estimated skeletal muscle mass ( 6.0 % and 10.7 % for total and thigh , respectively ) increased ( P < .05 ) in the K-walk group but not in the control group . Functional ability also increased significantly only in the K-walk group ( P < .05 ) ; however , there was no change in the estimated peak oxygen uptake(absolute and relative to body mass ) for either group . Conclusion The results of the current study indicate that 6 weeks of KAATSU-walk training did not simultaneously improve cardiovascular and muscular fitness  of older participants . However , it significantly increased muscular size and strength as well as functional ability of active older men and women Abstract Vechin , FC , Libardi , CA , Conceição , MS , Damas , FR , Lix and rão , ME , Berton , RPB , Tricoli , VAA , Roschel , HA , Cavaglieri , CR , Chacon-Mikahil , MPT , and Ugrinowitsch , C. Comparisons between low-intensity resistance training with blood flow restriction and high-intensity resistance training on quadriceps muscle mass and strength in elderly . J Strength Cond Res 29(4 ) : 1071–1076 , 2015—High-intensity resistance training ( HRT ) has been recommended to offset age-related loss in muscle strength and mass . However , part of the elderly population is often unable to exercise at high intensities . Alternatively , low-intensity resistance training with blood flow restriction ( LRT-BFR ) has emerged . The purpose of this study was to compare the effects of LRT-BFR and HRT on quadriceps muscle strength and mass in elderly . Twenty-three elderly individuals , 14 men and 9 women ( age , 64.04 ± 3.81 years ; weight , 72.55 ± 16.52 kg ; height , 163 ± 11 cm ) , undertook 12 weeks of training . Subjects were ranked according to their pretraining quadriceps cross-sectional area ( CSA ) values and then r and omly allocated into one of the following groups : ( a ) control group , ( b ) HRT : 4 × 10 repetitions , 70–80 % one repetition maximum ( 1RM ) , and ( c ) LRT-BFR : 4 sets ( 1 × 30 and 3 × 15 repetitions ) , 20–30 % 1RM . The occlusion pressure was set at 50 % of maximum tibial arterial pressure and sustained during the whole training session . Leg press 1RM and quadriceps CSA were evaluated at before and after training . A mixed-model analysis was performed , and the significance level was set at p ⩽ 0.05 . Both training regimes were effective in increasing pre- to post-training leg press 1RM ( HRT : ∼54 % , p < 0.001 ; LRT-BFR : ∼17 % , p = 0.067 ) and quadriceps CSA ( HRT : 7.9 % , p < 0.001 ; L 
    Output:
    
Blood flow restriction aerobic exercise  increased measures of aerobic fitness and performance in younger adults when using occlusion pressures ≥130 mm Hg .
In older adults  , measures of aerobic performance improved ; however , measures of aerobic fitness remained unchanged .
Short-term BFR aerobic exercise seems to offer a valid method of improving aerobic performance and fitness in healthy adults when using occlusion pressures ≥130 mm Hg .
Conversely , it seems to strictly enhance aerobic performance in older adults without impacting aerobic fitness , potentially suggesting different mechanisms of adaptation between older and younger individuals .
Despite method ological limitations , BFR aerobic exercise seems to have applications in scenarios where high-intensity aerobic exercise is not appropriate , although more high- quality research is needed to further demonstrate this