***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 The potential purpose of near‐infrared spectroscopy ( NIRS ) as a clinical application in patients with chronic heart failure ( CHF ) is the identification of limitations in O2 delivery or utilization during exercise . The objective of this study was to evaluate absolute and relative test – retest reliability of skeletal muscle oxygenation measurements in patients with CHF . Thirty patients with systolic heart failure ( left ventricular ejection fraction 31 ± 8 % ) performed 6‐min constant‐load cycling tests at 80 % of the anaerobic threshold ( AT ) with tissue saturation index ( TSI ) measurement at the vastus lateralis . Tests were repeated after 10 ± 5 days to evaluate reliability . Absolute reliability was assessed with limits of agreement ( LoA , expressed as bias ± r and om error ) and coefficients of variation ( CV ) for absolute values ( LoA range : 0·4 ± 6·2 % to 0·6 ± 7·9 % ; CV range : 4·7–7·1 % ) , amplitudes ( LoA range −0·5 ± 5·8 % to −0·7 ± 6·8 % ; CV range : 26·2–42·1 % ) , onset and recovery kinetics ( mean response times ; LoA 0·4 ± 9·5 s , CV 23·5 % and LoA −5·8 ± 50·8 s , CV 67·4 % respectively ) and overshoot characteristics ( CV range 45·7–208·6 % ) . Relative reliability was assessed with intraclass correlation coefficients for absolute values ( range 0·74–0·90 ) , amplitudes ( range 0·85–0·92 ) , onset and recovery kinetics ( 0·53 and 0·51 , respectively ) and overshoot characteristics ( range 0·17–0·74 ) . In conclusion , absolute reliability of absolute values and onset kinetics seems acceptable for serial within‐subject comparison , and as such , for evaluation of treatment effects . Absolute reliability of amplitudes and recovery kinetics is considered unsatisfactory . Relative reliability of absolute values and amplitudes is sufficient for purpose s of physiological distinction between patients with CHF . Despite lower relative reliability , kinetics may still be useful for clinical application This study examined the effects of Sprint Interval Cycling ( SIT ) on muscle oxygenation kinetics and performance during the 30 - 15 intermittent fitness test ( IFT ) . Twenty-five women hockey players of Olympic st and ard were r and omly selected into an experimental group ( EXP ) and a control group ( CON ) . The EXP group performed six additional SIT sessions over six weeks in addition to their normal training program . To explore the potential training-induced change , EXP subjects additionally completed 5 x 30s maximal intensity cycle testing before and after training . During these tests near-infrared spectroscopy ( NIRS ) measured parameters ; oxyhaemoglobin + oxymyoglobin ( HbO2 + MbO2 ) , tissue deoxyhaemoglobin + deoxymyoglobin ( HHb+HMb ) , total tissue haemoglobin ( tHb ) and tissue oxygenation ( TSI % ) were taken . In the EXP group ( 5.34±0.14 to 5.50±0.14m.s-1 ) but not the CON group ( pre = 5.37±0.27 to 5.39±0.30m.s-1 ) significant changes were seen in the 30 - 15IFT performance . EXP group also displayed significant post-training increases during the sprint cycling : ΔTSI ( −7.59±0.91 to −12.16±2.70 % ) ; ΔHHb+HMb ( 35.68±6.67 to 69.44±26.48μM.cm ) ; and ΔHbO2 + MbO2 ( −74.29±13.82 to −109.36±22.61μM.cm ) . No significant differences were seen in ΔtHb ( −45.81±15.23 to −42.93±16.24 ) . NIRS is able to detect positive peripheral muscle oxygenation changes when used during a SIT protocol which has been shown to be an effective training modality within elite athletes Introduction : The aim of this study was to determine whether calf compression sleeves ( CS ) affects physiological and biomechanical parameters , exercise performance , and perceived sensations of muscle fatigue , pain and soreness during prolonged ( ~2 h 30 min ) outdoor trail running . Methods : Fourteen healthy trained males took part in a r and omized , cross-over study consisting in two identical 24-km trail running sessions ( each including one bout of running at constant rate on moderately flat terrain , and one period of all-out running on hilly terrain ) wearing either degressive CS ( 23 ± 2 mmHg ) or control sleeves ( CON , < 4 mmHg ) . Running time , heart rate and muscle oxygenation of the medial gastrocnemius muscle ( measured using portable near-infrared spectroscopy ) were monitored continuously . Muscle functional capabilities ( power , stiffness ) were determined using 20 s of maximal hopping before and after both sessions . Running biomechanics ( kinematics , vertical and leg stiffness ) were determined at 12 km·h−1 at the beginning , during , and at the end of both sessions . Exercise-induced Achilles tendon pain and delayed onset calf muscles soreness ( DOMS ) were assessed using visual analog scales . Results : Muscle oxygenation increased significantly in CS compared to CON at baseline and immediately after exercise ( p < 0.05 ) , without any difference in deoxygenation kinetics during the run , and without any significant change in run times . Wearing CS was associated with ( i ) higher aerial time and leg stiffness in running at constant rate , ( ii ) with lower ground contact time , higher leg stiffness , and higher vertical stiffness in all-out running , and ( iii ) with lower ground contact time in hopping . Significant DOMS were induced in both CS and CON ( > 6 on a 10-cm scale ) with no difference between conditions . However , Achilles tendon pain was significantly lower after the trial in CS than CON ( p < 0.05 ) . Discussion : Calf compression did not modify muscle oxygenation during ~2 h 30 of trail running but significantly changed running biomechanics and lower limb muscle functional capabilities toward a more dynamic behavior compared to control session . However , wearing compression sleeves did not affect performance and exercise-induced DOMS , while it minimized Achilles tendon pain immediately after running The effects of  intermittent hypoxic exposure ( IHE )  on cerebral and muscle oxygenation , arterial oxygen saturation ( SaO2 ) , and respiratory gas exchange during a 20-km cycle time trial ( 20TT ) were examined ( n=9 ) in a placebo-controlled r and omized design . IHE ( 7:3 min hypoxia to normoxia ) involved 90-min sessions for 10 days , with SaO2 clamped at ~80 % . Prior to , and 2 days after the intervention , a 20TT was performed . During the final minute of the 20TT , in the IHE group only , muscle oxyhemoglobin ( oxy-Hb ) was elevated ( mean+/-95 % confidence interval 1.3+/-1.2 ΔmicroM , p=0.04 ) , whereas cerebral oxy-Hb was reduced ( -1.9%+/-1.0 % , p<0.01 ) post intervention compared with baseline . The 20TT performance was unchanged between groups ( p=0.7 ) . In the  IHE group , SaO2 was higher ( 1.0+/-0.7Δ% , p=0.006 ) and end-tidal PCO2 was lower ( -1.2+/-0.1 mm Hg , p=0.01 ) during the final stage of the 20TT post intervention compared with baseline . In summary , reductions in muscle oxy-Hb and systemic SaO2 occurring at exercise intensities close to maximal at the end of a 20TT were offset by IHE , although this was not translated into improved performance Abstract In this study , we wished to determine whether the observed reduction in quadriceps muscle oxygen availability , reported during repetitive bouts of isometric exercise in simulated sailing efforts ( i.e. hiking ) , is because of restricted muscle blood flow . Six national-squad Laser sailors initially performed three successive 3-min hiking bouts followed by three successive 3-min cycling tests sustained at constant intensities reproducing the cardiac output recorded during each of the three hiking bouts . The blood flow index ( BFI ) was determined from assessment of the vastus lateralis using near-infrared spectroscopy in association with the light-absorbing tracer indocyanine green dye , while cardiac output was determined from impedance cardiography . At equivalent cardiac outputs ( ranging from 10.3±0.5 to 14.8±0.86 L · min−1 ) , the increase from baseline in vastus lateralis BFI across the three hiking bouts ( from 1.1±0.2 to 3.1±0.6 nM · s−1 ) was lower ( P = 0.036 ) than that seen during the three cycling bouts ( from 1.1±0.2 to 7.2±1.4 nM · s−1 ) ( Cohen 's d : 3.80 nM · s−1 ) , whereas the increase from baseline in deoxygenated haemoglobin ( by ∼17.0±2.9 μM ) ( an index of tissue oxygen extraction ) was greater ( P = 0.006 ) during hiking than cycling ( by ∼5.3±2.7 μM ) ( Cohen 's d : 4.17 μM ) . The results suggest that reduced vastus lateralis muscle oxygen availability during hiking arises from restricted muscle blood flow in the isometrically acting quadriceps muscles Muscle ischemia and reperfusion induced by ischemic preconditioning ( IPC ) can improve performance in various activities . However , the underlying mechanisms are still poorly understood . The purpose of this study was to examine the effects of IPC  on muscle hemodynamics and oxygen ( O2 ) uptake during repeated maximal contractions . In a cross-over , r and omized , single-blind study , 10 strength-trained men performed 5 sets of 5 maximal voluntary knee extensions of the right leg  on an isokinetic dynamometer , preceded by either IPC of the right lower limb (  
    Output:
    
This systematic review highlighted a number of key findings in 16 sporting activities .
Overall , NIRS information can be used as a marker of skeletal muscle oxidative capacity and for analyzing muscle performance factors .