Background: Quantification of training intensities via current formulas (e.g. 75% of the estimated maximum heart rate (HR-peak)) is practical and a time saving compromise. However misinterpretations of cardiorespiratory fitness in persons with MS (pwMS) may lead to stagnancy or loss of exercise capacity. Objectives: Feasibility of different training intensities of established training formulas in pwMS using a method comparison according to Bland-Altman. Methods: 83 pwMS were included and the thresholds were determined via breathing gas analysis of peak oxygen consumption (VO2) and carbondioxide (CO2). The sample was divided according to the expandend disability status scale (EDSS) in mildly (EDSS 1.0-4.0) and moderately impaired (EDSS 4.5 - 6.5). The formulas (210 age)*0.65, (210-age)*0.70, (210-age)*0.80, 180-age, 65% of the effective highest heart rate during CPET (HRPeak), 70%HR-peak, 75% HR-peak and 80% HR-peak were used for the estimation of the training heart rates. Method comparisons were performed using Passing-Bablok regression and Bland-Altman plots. All values are expressed as mean and 95% confidence interval (CI). Results: Passing-Bablok regression show that for mildly impaired pwMS 70% and 75% HR-peak show an agreement with the threshold values. For severely impaired pwMS 65% HR-peak showed by trend an agreement with the threshold values. Other formula values missed the criteria for agreement. Conclusion: This study indicates that 70% and 75% HR-peak for moderately impaired PwMS gave adequate training intensities comparable to the threshold values.