***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: Prior peripheral hypoxia induced via remote ischemic preconditioning ( IPC ) can improve physical performance in male athletes through improved O2 delivery and utilization . Since females may have an innate protective mechanism against ischemia-reperfusion injury , and since muscle metabolism during contraction differs between sexes , it is relevant to examine the impact of sex in response to IPC to determine whether it is also ergogenic in females . In a r and omized , crossover , single-blind study , we investigated muscle performance , hemodynamic and O2 uptake in strength-trained males ( n = 9 ) and females ( n = 8) performing five sets of 5 maximum voluntary knee extensions on an isokinetic dynamometer , preceded by either IPC ( 3 × 5-min ischemia/5-min reperfusion cycles at 200 mmHg ) or SHAM ( 20 mmHg ) . Changes in deoxy-hemoglobin ( Δ[HHb ] , expressed in percentage of arterial occlusion and considered an index of O2 extraction ) , and total hemoglobin ( Δ[THb ] ) concentrations of the vastus lateralis muscle were continuously monitored by near-infrared spectroscopy . The metabolic efficiency of the contractions was calculated as the average force/Δ[HHb]avg ratio . Cohen 's effect sizes ( ES ) ± 90 % confidence limits were used to estimate IPC-induced changes and sex differences . IPC increased total muscular force in males only ( 13.0 % , ES 0.64 , 0.37;0.90 ) , and this change was greater than in females ( 10.4 % difference , ES 0.40 , 0.10;0.70 ) . Percent force decrement was only attenuated in females ( −19.8 % , ES −0.38 , −0.77;0.01 ) , which was clearly different than males ( sex difference : ES 0.45 , −0.16;1.07 ) . IPC also induced different changes between sexes for average muscle O2 uptake in set 2 ( males : 6.4 % vs. females : −16.7 % , ES 0.21 , −0.18;0.60 ) , set 3 ( males : 7.0 % vs. females : −44.4 % , ES 0.56 , −0.17;1.29 ) , set 4 ( males : 9.1 % vs. females : −40.2 % , ES 0.51 , −0.10;1.13 ) , and set 5 ( males : 10.2 % vs. females : −40.4 % , ES 0.52 , −0.04;1.09 ) . However , metabolic efficiency was not meaningfully different between conditions and sexes . IPC  increased muscle blood volume ( ↑[THb ] ) at rest and during recovery between sets , to the same extent in both sexes . Despite a similar IPC-induced initial increase in O2 delivery in both sexes , males displayed greater peripheral O2 extraction and greater strength enhancement . This ergogenic effect appears to be mediated in part via an up regulated oxidative function in males . We conclude that strength-trained males might benefit more from IPC than their female counterparts during repeated , maximal efforts This study investigated the effects of ischemic preconditioning ( IPC ) on the ratings of perceived exertion ( RPE ) , surface electromyography , and pulmonary oxygen uptake ( V̇o2 ) onset kinetics during cycling until exhaustion at the peak power output attained during an incremental test . A group of 12 recreationally trained cyclists volunteered for this study . After determination of peak power output during an incremental test , they were r and omly subjected on different days to a performance protocol preceded by intermittent bilateral cuff pressure inflation to 220 mmHg ( IPC ) or 20 mmHg ( control ) . To increase data reliability , the performance visits were replicated , also in a r and om manner . There was an 8.0 % improvement in performance  after IPC ( control : 303 s , IPC 327 s , factor SDs of ×/÷1.13 , P = 0.01 ) . This change was followed by a 2.9 % increase in peak V̇o2 ( control : 3.95 l/min , IPC : 4.06 l/min , factor SDs of ×/÷1.15 , P = 0.04 ) , owing to a higher amplitude of the slow component of the V̇o2 kinetics ( control : 0.45 l/min , IPC : 0.63 l/min , factor SDs of ×/÷2.21 , P = 0.05 ) . There was also an attenuation in the rate of increase in RPE ( P = 0.01 ) and a progressive increase in the myoelectrical activity of the vastus lateralis muscle ( P = 0.04 ) . Furthermore , the changes in peak V̇o2 ( r = 0.73 , P = 0.007 ) and the amplitude of the slow component ( r = 0.79 , P = 0.002 ) largely correlated with performance improvement . These findings provide a link between improved aerobic metabolism and enhanced severe-intensity cycling performance  after IPC . Furthermore , the delayed exhaustion after IPC under lower RPE and higher skeletal muscle activation suggest they have a role on the ergogenic effects of IPC on endurance performance Purpose Endurance athletes often compete and train at altitude where exercise capacity is reduced . Investigating acclimation strategies is therefore critical . Ischemic preconditioning ( IPC ) can improve endurance performance at sea level through improved O2 delivery and utilization , which could also prove beneficial at altitude . However , data are scarce , and there is no study at altitudes commonly visited by endurance athletes . Methods In a r and omized , crossover study , we investigated performance and physiological responses in 13 male endurance cyclists during four 5-km cycling time trials ( TT ) , preceded by either IPC ( 3 × 5 min ischemia/5-min reperfusion cycles at 220 mm Hg ) or SHAM ( 20 mm Hg ) administered to both thighs , at simulated low ( FIO2 0.180 , ~1200 m ) and moderate ( FIO2 0.154 , ~2400 m ) altitudes . Time to completion , power output , cardiac output ( Q˙ ) , arterial O2 saturation ( SpO2 ) , quadriceps tissue saturation index ( TSI ) and RPE were recorded throughout the TT . Differences between IPC and SHAM were analyzed at every altitude using Cohen effect size ( ES ) and compared with the smallest worthwhile change . Results At low altitude , IPC possibly improved time to complete the TT ( −5.2 s , −1.1 % ; Cohen ES ± 90 % confidence limits −0.22 , −0.44 ; 0.01 ) , power output ( 2.7 % ; ES 0.21 , 0.08 ; 0.51 ) , and Q˙ ( 5.0 % ; ES 0.27 , 0.00 ; 0.54 ) , but did not alter SpO2 , muscle TSI , and RPE . At moderate altitude , IPC  likely enhanced completion time ( −7.3 s ; −1.5 % ; ES −0.38 , −0.55 ; −0.20 ) , and power output in the second half of the TT ( 4.6 % ; ES 0.28 , −0.15 ; 0.72 ) , increased SpO2 ( 1.0 % ; ES 0.38 , −0.05 ; 0.81 ) , and decreased TSI ( −6.5 % ; ES −0.27 , −0.73 ; 0.20 ) and RPE ( −5.4 % , ES −0.27 , −0.48 ; −0.06 ) . Conclusions Ischemic preconditioning may provide an immediate and effective strategy to defend SpO2 and enhance high-intensity endurance performance at moderate altitude Purpose Recent studies have reported ischemic preconditioning ( IPC ) can acutely improve endurance exercise performance  in athletes . However , placebo and nocebo effects have not been sufficiently controlled , and the effect on aerobic metabolism parameters that determine endurance performance ( e.g. , oxygen cost of running , lactate threshold , and maximal oxygen uptake [ V˙O2max ] ) has been equivocal . Thus , we circumvented limitations from previous studies to test the effect of IPC on aerobic metabolism parameters and endurance performance in well-trained runners . Methods Eighteen runners ( 14 men/4 women ) were su bmi tted to three interventions , in r and om order : IPC ; sham intervention ( SHAM ) ; and resting control ( CT ) . Subjects were told both IPC and SHAM would improve performance compared to CT ( i.e. , similar placebo induction ) , and IPC would be harmless despite circulatory occlusion sensations ( i.e. , nocebo avoidance ) . Next , pulmonary ventilation and gas exchange , blood lactate concentration , and perceived effort were measured during a discontinuous incremental test on a treadmill . Then , a supramaximal test was used to verify the V˙O2max and assess endurance performance ( i.e. , time to exhaustion ) . Results Ventilation , oxygen uptake , carbon dioxide output , lactate concentration , and perceived effort were similar among IPC , SHAM , and CT throughout the discontinuous incremental test ( P > 0.05 ) . Oxygen cost of running , lactate threshold , and V˙O2max were also similar among interventions ( P > 0.05 ) . Time to exhaustion was longer after IPC ( mean ± SEM , 165.34 ± 12.34 s ) and SHAM ( 164.38 ± 11.71 s ) than CT ( 143.98 ± 12.09 s ; P = 0.02 and 0.03 , respectively ) , but similar between IPC and SHAM ( P = 1.00 ) . Conclusions IPC did not change aerobic metabolism parameters , whereas improved endurance performance . The IPC improvement , however , did not surpass the effect of a placebo intervention OBJECTIVES The purpose of this investigation was to examine the effectiveness of intermittent lower limb occlusion in augmenting recovery from exercise induced muscle damage ( EIMD ) in physically active males . DESIGN R and omized controlled trial , double blind . METHODS Sixteen healthy recreationally active male participants were r and omly assigned to an intermittent occlusion ( OCC ; n=8 ) or control ( SHAM ; n=8 ) group . The EIMD protocol comprised of 100 drop-jumps , from a 0.6 m box . Indices of muscle damage were creatine kinase ( CK ) , thigh-circumference ( TC ) , muscle soreness ( DOMS ) , counter-movement jump ( CMJ ) and maximal isometric voluntary contraction ( MIVC ) . Measurements were assessed pre , 24h , 48h and 72h following exercise . RESULTS There was a significant time effect for all indices of muscle damage suggesting EIMD was present following the exercise protocol . The decrease in MIVC was significantly attenuated in the OCC group compared to the SHAM group at 24 ( 90.4±10.7 vs. 81.5±6.7 % ) , 48 ( 96.2±6.1 vs. 84.5±7.1 % ) and 72h ( 101.1±4.2 vs. 89.7±7.5 % ) . The CK response was reduced in the OCC group at 24 ( 335±87 vs. 636±300 IU ) and 48h ( 244±70 vs. 393±248 IU ) , compared to the SHAM group . DOMS was significantly lower in the OCC compared to the SHAM group at 24 , 48 and 72h post EIMD . There was no effect of OCC on CMJ or TC . CONCLUSIONS This investigation shows that intermittent lower limb occlusion administered after a damaging bout of exercise reduces indices of muscle damage and accelerates the recovery in physically active males This study evaluated the acute effect of ischemic preconditioning ( IPC ) on a high-intensity intermittent exercise performance and physiological indicators in amateur soccer players . Thirteen players ( 21.5 ± 2 yrs ) attended three trials separated by 3–5 days in a counterbalanced r and omized cross-over design : IPC ( 4 × 5-min occlusion 220 mmHg/reperfusion 0 mmHg ) in each thigh ; SHAM ( similar to the IPC protocol but “ occlusion ” at 20 mmHg ) and control ( seated during the same time of IPC ) . After 6-min of each trial ( IPC , SHAM or control ) , the players performed the  YoYo Intermittent Endurance Test level 2 ( YoYoIE2 ) . The distance covered in the YoYoIE2 ( IPC 867 ± 205 m ; SHAM 873 ± 212 m ; control 921 ± 206 m ) was not different among trials ( p = 0.10 ) , furthermore , lactate concentration and rate of perceived exertion did not differ ( P > 0.05 ) among protocol s. There were also no significant differences in either mean heart rate ( HR ) or peak HR ( p > 0.05 ) for both IPC and SHAM compared to control . Therefore , we conclude that  acute IPC  does not influence high-intensity intermittent exercise performance in amateur soccer players and that rate of perceived ex 
    Output:
    
Overall , the results show that IPC has a minimal or nonsignificant effect on performance considering the fitness level of the individuals , using statistical approaches ( i.e. , tests with P value , ES , and SWC ) .