Methods and devices for comprising: obtaining an estimated heart rate training zone for a user; measuring the pulse rate of the user; and performing a plurality of computerized talk tests, such that a higher number of computerized talk tests are performed when the measured pulse rate is more in the vicinity of the estimated heart rate training zone than outside the vicinity of the estimated heart rate training zone. Other embodiments include devices for controlling an exercise program, comprising: an interface to an element configured to play auditory signals, and an interface to an element configured to record a user's speech in accordance with the auditory signals; wherein the device is configured to provide an indication upon identifying involuntary interruptions in the user's speech.