Background: The few previous studies that focused on the effects of compression garments (CG) on distance running performance have simulta neously measured electromyogram,physiological,and perceptual parameters.Therefore,this study investigated the effects of CG on muscle activation and median frequency during and after distance running,as well as blood-lactate concentration and rating of perceived exertion (RPE) during distance running.Methods: Eight healthy male recreational runners were recruited to randomly perform two 40 min treadmill running trials,one with CG,and the other with control garment made of normal cloth.The RPE and the surface electromyography (EMG) of 5 lower extremity muscles including gluteus maximus (GM),rectus femoris (RF),semitendinosus (ST),tibialis anterior (TA),and gastrocnemius (GAS) were measured during the running trial.The blood-lactate levels before and after the running trial were measured.Results: Wearing CG led to significant lower muscle activation (p ＜ 0.05) in the GM (decreased 7.40％-14.31％),RF (decreased 4.39％-4.76％),and ST (decreased 3.42％-7.20％) muscles;moreover,significant higher median frequency (p ＜ 0.05) in the GM (increased 5.57％) and ST (increased 10.58％) muscles.Wearing CG did not alter the RPE values or the blood-lactate levels (p ＞ 0.05).Conclusion: Wearing CG was associated with significantly lower muscle activation and higher median frequency in the running-related key muscles during distance running.This finding suggested that wearing CG may improve muscle function,which might enhance running performance and prevent muscle fatigue.