A method in the field of health related-fitness for preparing and monitoring a customized exercise strategy and prescription based on scientific and concrete data pertaining to a person's health, the method comprising the following steps: - measuring, by measuring devices, the person's following fitness components: 1: cardiovascular endurance, 2: muscular strength component, 3: muscular flexibility component and 4: body composition, - calculating each of the aforementioned values of components as percentage ratios of the person's total fitness score; - calculating weighted percentage ratios and fitness component scores separately for each of the person's fitness components' values based on age and gender-related fitness component norms; - calculating a weighted total fitness score based on the scores of all of the fitness components; - generating and displaying a graphical of fitness map, this fitness map comprising and graphically representing the ratios of said calculated fitness components; whereby preparing and monitoring the customized exercise strategy comprises, with the use of software executed on a suitable system and the graphical map - prioritizing the ratios of the health related fitness components in the customized exercise strategy as follows; - allocating the biggest ratio to exercises relating to cardiovascular endurance component - the second biggest ratio to exercises relating to muscular strength, - the third biggest ratio to exercises relating to body composition component and - the fourth biggest ratio to exercises relating to the muscular flexibility component; - determining an exercise strategy in accordance with measurements of the person's fitness components the weighted fitness score and the priority of the health related fitness components; - dividing said exercise strategy into exercises in the field of improving cardio components, strength components and flexibility components each component and fitness exercise divided into a further primary and secondary component; - determining, based on the further primary and secondary components of each of the components, a detailed order of exercises in each of the fields and for each of the components; and - preparing a person's customized exercise strategy based on the determined exercise strategy, the person's customized exercise strategy depending on the frequency and time, which can be spared by the person for exercise, and comprising an order of exercises to be performed; - and monitoring a person's customized exercise session to improve the person's fitness components. - measuring, by measuring devices, the person's following fitness components: 1: cardiovascular endurance, 2: muscular strength component, 3: muscular flexibility component and 4: body composition, 1: cardiovascular endurance, 2: muscular strength component, 3: muscular flexibility component and 4: body composition, - calculating each of the aforementioned values of components as percentage ratios of the person's total fitness score; - calculating weighted percentage ratios and fitness component scores separately for each of the person's fitness components' values based on age and gender-related fitness component norms; - calculating a weighted total fitness score based on the scores of all of the fitness components; - generating and displaying a graphical of fitness map, this fitness map comprising and graphically representing the ratios of said calculated fitness components; - prioritizing the ratios of the health related fitness components in the customized exercise strategy as follows; - allocating the biggest ratio to exercises relating to cardiovascular endurance component - the second biggest ratio to exercises relating to muscular strength, - the third biggest ratio to exercises relating to body composition component and - the fourth biggest ratio to exercises relating to the muscular flexibility component; - allocating the biggest ratio to exercises relating to cardiovascular endurance component - the second biggest ratio to exercises relating to muscular strength, - the third biggest ratio to exercises relating to body composition component and - the fourth biggest ratio to exercises relating to the muscular flexibility component; - determining an exercise strategy in accordance with measurements of the person's fitness components the weighted fitness score and the priority of the health related fitness components; - dividing said exercise strategy into exercises in the field of improving cardio components, strength components and flexibility components each component and fitness exercise divided into a further primary and secondary component; - determining, based on the further primary and secondary components of each of the components, a detailed order of exercises in each of the fields and for each of the components; and - preparing a person's customized exercise strategy based on the determined exercise strategy, the person's customized exercise strategy depending on the frequency and time, which can be spared by the person for exercise, and comprising an order of exercises to be performed; - and monitoring a person's customized exercise session to improve the person's fitness components.