Fitness device and resistance adjustment method thereof

A resistance adjustment method of a fitness device, wherein the fitness device includes an exercise assembly and at least one damping module that is connected to the exercise assembly;

• wherein the damping module includes a pull rope, a resistance source that is connected to the pull rope, a linear displacement sensor that is electrically coupled to the resistance source, a resistance sensor that is electrically coupled to the resistance source, and a processor that is electrically coupled to the resistance source, the linear displacement sensor, and the resistance sensor;
• and wherein the resistance source is configured to output an output resistance and to control a stretching length of the pull rope according to a target resistance setting value, the resistance adjustment method including the following steps:
• a measuring step that is implemented to sense the stretching length of the pull rope to generate a linear displacement sensing signal by the linear displacement sensor and that is implemented to sense the output resistance of the resistance source to generate a resistance sensing signal by the resistance sensor;
• a calculating step that is implemented to calculate an exercise frequency according to the linear displacement sensing signal and the resistance sensing signal by the processor;
• and
• an adjusting step that is implemented to compare the exercise frequency and a predetermined exercise frequency to control the output resistance of the resistance source by the processor.