Omni Scale Perceived Exertion responses in obese and normal weight male adolescents during cycle exercise.

AIM: The Children's OMNI scale of perceived exertion (OMNI Scale) has been validated with children. However, the scale's validity to assess exertional perceptions in obese (OB) adolescents has not been investigated. The aim of this paper was to validate and compare exertional perceptions using the OMNI Scale between OB and normal weight (NW) adolescent males. METHODS: Eighteen OB and 23 NW adolescent males (age: 12-14) participated in a perceptual estimation paradigm with a load incremented cycle ergometer protocol. Heart rate (HR;beats·min-1), oxygen uptake (VO2 mL·min-1 and mL·kg-1·min-1) and rating of perceived exertion (RPE) for the overall body (RPE-O), legs (RPE-L), and chest (RPE-C) were determined at the end of each continuously administered 3-min power output stage as subjects cycled stage-wise incrementally to exhaustion beginning with 4 sub-maximal stages. RESULTS: For OB, 17 completed 4 stages and 3 attained maximal stage 7. For NW, all 18 completed stage 5, and 8 reached maximal stage 7. RPE ranges (i.e. stage 1 to stage 7) for OB and NW were: Stage 1: RPE-O (1.0±1.6, 1.2±0.6), RPE-L (0.9±1.4, 0.9±0.8) and RPE-C (0.9±1.1, 0.9±0.7). Stage 7: RPE-O (7.3±2.3, 8.8±1.4), RPE-L (8.0±2.0, 8.8±1.4) and RPE-C (7.7±2.1, 7.6±3.0). Linear regression for all three RPEs correlated significantly (P<0.001) with HR and VO2 (0.61 to 0.79) for both cohorts. ANOVA indicated no differences between RPE-O and differentiated RPE (RPE-C and RPE-L) at each stage. The RPE responses between OB and NW adolescent males were analyzed by the Bland Altman plot, which indicated significant agreement (95% CI) between the two groups. CONCLUSION: The OMNI Scale is valid for use with 12-14 year-old OB and NW adolescent males. The scale seems to be robust and RPE remained similar for the two cohorts with the same fat free mass but with different fat mass. Hence OMNI scale RPE seems to be able to reflect effort delivered by metabolically active muscle during cycle exercise.