Validation of omni scale of perceived exertion during prolonged cycling

Purpose: The present investigation was conducted to validate the OMNI ratings of perceived exertion (RPE) scale during prolonged cycle exercise when subjects were supplemented with either carbohydrate or placebo. Methods: Fifteen trained cyclists cycled for 2.5 h at approximately 60% maximal watts on two occasions while receiving 4 mL·kg^-1-15 min^-1 carbohydrate (6%) (C) or placebo (P) beverages in a randomized, counterbalanced design. Concurrent and construct validity was established by evaluating perceptual responses with both the OMNI and Borg RPE scales every 20 min throughout the trials. Results: The pattern of change in RPE over time was significantly different between C and P ingestion (P < 0.05), with an attenuated RPE response in C found at the hundredth minute for both the OMNI and Borg scales. The pattern of change in the respiratory exchange ratio and carbohydrate oxidation rates were significantly greater (P < 0.001) in the C than P condition. RPE-OMNI was positively and linearly related to the RPE-BORG; r = 0.60-0.98 (P < 0.01) throughout exercise for both the C and P conditions. Conclusions: Concurrent and construct evidence supports the use of the OMNI-cycle scale by adult men to estimate RPE during prolonged cycle exercise under differing conditions of carbohydrate supplementation.