Method of route planning for physical training purposes, wherein during movement along a planned route the heart rate of the training subject should be kept within a permitted range; comprising the steps of: as preparatory steps prior to the actual route planning: - storing in a navigation device map data of an area concerned that includes starting and target points, the map data including also altitude data; - determining a load profile of the subject including: - measuring the heart rate of the subject along routes of different steepness; - storing the so obtained data in an electronic table stored in the device; the actual route planning includes the further steps of: - searching possible routes between said starting and target points; - dividing a first possible route into sections that have respective constant steepness; - determining the respective costs typical of each section based on the steepness data of the section using the table of said stored load profile, wherein the cost represents the load when the subject takes that section; - calculating from the determined cost values in the course of the movement of the subject proceeding along said first possible route his expected heart rate; - examining whether the expected heart rate will remain in the permitted range along the whole first route; - accepting the first route as planned route if the examination shows that the heart rate will be in the permitted range or repeating the route planning steps for possible routes if examination of the first route shows that the heart rate will not remain in the permitted range, characterized in, that during the step of determining the load profile the time elapsed since the beginning of the movement is also stored in said table, and said determination step is carried out repeatedly and the extent of regeneration of the subject is determined as a result of a larger load followed by a smaller load; and at said calculation step of the expected heart rate the cost of any section depends also on the time elapsed since the beginning of the movement and the total load during said elapsed time; and in said calculating step examining at each section whether at the previous section or sections there was a decrease in the required level of effort in which the subject could have partially regenerated and if such is experienced the previously determined regeneration is also taken into account in determining the cost associated with the concerned section. as preparatory steps prior to the actual route planning: - storing in a navigation device map data of an area concerned that includes starting and target points, the map data including also altitude data; - determining a load profile of the subject including: - measuring the heart rate of the subject along routes of different steepness; - storing the so obtained data in an electronic table stored in the device; - storing in a navigation device map data of an area concerned that includes starting and target points, the map data including also altitude data; - determining a load profile of the subject including: - measuring the heart rate of the subject along routes of different steepness; - storing the so obtained data in an electronic table stored in the device; - measuring the heart rate of the subject along routes of different steepness; - storing the so obtained data in an electronic table stored in the device; the actual route planning includes the further steps of: - searching possible routes between said starting and target points; - dividing a first possible route into sections that have respective constant steepness; - determining the respective costs typical of each section based on the steepness data of the section using the table of said stored load profile, wherein the cost represents the load when the subject takes that section; - calculating from the determined cost values in the course of the movement of the subject proceeding along said first possible route his expected heart rate; - examining whether the expected heart rate will remain in the permitted range along the whole first route; - accepting the first route as planned route if the examination shows that the heart rate will be in the permitted range or repeating the route planning steps for possible routes if examination of the first route shows that the heart rate will not remain in the permitted range, - searching possible routes between said starting and target points; - dividing a first possible route into sections that have respective constant steepness; - determining the respective costs typical of each section based on the steepness data of the section using the table of said stored load profile, wherein the cost represents the load when the subject takes that section; - calculating from the determined cost values in the course of the movement of the subject proceeding along said first possible route his expected heart rate; - examining whether the expected heart rate will remain in the permitted range along the whole first route; - accepting the first route as planned route if the examination shows that the heart rate will be in the permitted range or repeating the route planning steps for possible routes if examination of the first route shows that the heart rate will not remain in the permitted range,