(US5458548-A)      A fitness quantification device for an exercise machine having a stationary frame, an actuator movably coupled to said frame, and a resistance member coupled to said frame and said resistance member to provide resistance to movement of said actuator with respect to said frame, the fitness quantification device comprising:    a) a digital encoder coupled to said actuator and generating an output of electrical pulses corresponding to relative movement between said actuator and said frame;    b) a heart rate monitor worn by a user of the exercise machine during an exercise session, the monitor generating an output of electrical impulses corresponding to a current heart rate of the user, the monitor including a transmitter for transmitting impulses to a remote receiver; and    c) a programmable microprocessor including input means coupled to said digital encoder for receiving electrical pulses generated by the encoder and coupled to said heart rate monitor receiver for receiving impulses generated by the heart rate monitor;    d) a selectively actuated timer coupled to said microprocessor; and    e) a user interface means coupled to said microprocessor for input of data by the user and including a visual display for displaying a current value of said timer and a current value of an exercise parameter, said microprocessor being programmed:    i) to determine a minimum heart rate limit and a maximum heart rate limit for the user based on data input by the user; and    ii) to actuate said timer during intervals of said session wherein said input means receives impulses from the heart rate monitor receiver corresponding to a user current heart rate within the minimum and maximum heart rate limits and to disable said timer during intervals when said input means receives impulses from the heart rate monitor receiver corresponding to a user current heart rate outside the minimum and maximum heart rate limits, the current value of the timer thereby providing a measure of elapsed time during which the user's heart rate is between the minimum and maximum heart rate limits; and    iii) to count a number of electrical pulses generated by the digital encoder during the session and to determine the current value of the exercise parameter, the current value of the exercise parameter being a function of a count of the electrical pulses generated by the digital encoder.