Figure 3. Bland-Altman bias plot between Polar S810i estimate and IC measurement for rowing energy expenditure at 70% VO2max. 95% Limits of Agreement = -1.35 to 0.95; 95% CI = -0.45 to 0.05 B) Bland-Altman bias plot between SWA estimate and IC measurement for rowing energy expenditure at 70% VO2max. 95% Limits of Agreement = -0.87 to 1.28; 95% CI = -0.03 to 0.44. The middle solid line represents the mean difference between the methods, and the dashed lines represent the 95% limits of agreement..