Comparison of the Parameters Dynamics of two Heart Rate Analysis Methods before and after extreme Load

Using various methods of analyzing heart rate variations before and after extreme loads in the form of a super marathon (a distance of 100 kilometers), the authors use a large illustrative material and quantitative data to show, on the one hand, the high sensitivity of the methods to both test and extreme exertion, on the other hand, the ambiguity of the results obtained using the standard approach. Comparing the standard approach with the author's methodology, the authors come to the conclusion that there is a need for a critical revision of generally accepted recommendations. The transition from absolute values to relative values is proposed as a basis for revision. One of the options for an alternative approach is briefly discussed in this report