Ten healthy subjects (six males and four females) volunteered for this bench press exercise study. The "1-repetition maximum" (1RM) load was determined by increasing the weight until the subject was no longer capable of performing a single lift. Each subject then performed a "10-repetition maximum" (10RM) set with the resistance set at 80% of the 1RM. Following a rest of at least fifteen minutes, the resistance was increased by about 15% and the subject performed a second 10-repetition set with the Afterburner® mechanism activated. Activation of the Afterburner® mechanism consisted of opening the valve to the position of greatest flow. This resulted in a fairly linear decrease of the weight by about 30 pounds by the end of the exercise.

A force transducer was linked in series with the resistance to measure the actual forces exerted by the subject during each repetition. Electromyographical (EMG) electrodes were placed over the right pectoralis major and triceps brachii muscles of each subject to measure the electrical activity of these muscles during each repetition. The two EMG channels and the force channel were sampled by a computer at 1000 samples per second and the data were stored for later calculations. A metronome was used to provide a set cadence for each repetition to ensure uniformity between the two sets.