FITT stands for frequency, which is how often you exercise, intensity, which is how hard you exercise, time, which is how long each session lasts and what time of day you exercise, and type, which is what activities you do. All of these pieces are interconnected and have to be considered as a whole.
Below are some common frequency ranges: Power line frequency (normally 50 Hz or 60 Hz). Variable-frequency drives, which normally use a 1-20 kilohertz (kHz) carrier frequency. Audio frequency range: 15 Hz to 20 kHz (the range of human hearing).
