Abstract:

Abstract:Objective To explore the reliability and validation of intensity of self-guided brisk walking in simple obesity patients and to provide evidence for formulating special exercise prescription. Methods  One hundred simple obesity patients (BMI>28, obese group, O group) and 100 normal weight adults (BMI<24, normal weight group, NW group) performed two tests of 2-km brisk walking on alternate days at a self-guided pace (Test1 and Test2). The average pace, heart rate (HR),percentage of maximal heart rate (%HRmax) and ratings of perceived exertion (RPE) were measured during each test;the retest reliability of brisk walking was conducted by correlation test in all indexes of Test1 and Test2;criterion-related validation was analyzed through the threshold (60%-90%HRmax) recommended for improvements in cardiovascular fitness by American College of Sports Medicine (ACSM). Results There were no significant differences of all indexes within groups between Test1 and Test2 (all P>0.05) and correlation coefficients were higher than 0.9, suggesting high test-retest reliability. The pace was lowered (all P<0.01), HR was higher (all P<0.01), %HRmax was higher (all P<0.01) and there was no significant difference of RPE (P>0.05) in O group compared with NW group in Test1 and Test2. The relative exercise intensity in O group (72%HRmax) reached the threshold recommended by ACSM and criterion-related validation r=0.731 (P<0.01), but in NW group (59%HRmax) the threshold was lowered and criterion-related validation r=0.351 (P>0.05). Conclusion  Exercise intensity of self-guided brisk walking is suitable for simple obesity patients but not for normal weight individuals. RPE may be a valuable indicator for simple obesity patients to monitor exercise intensity of brisk walking.

Key words: simple obesity;brisk walking;exercise intensity;reliability;validation