The muscle action potentials (MAP) of the anterior deltoid, pectoralis major, biceps brachii, and the triceps muscle were studied by quantitative electromyography (emg) during a bench press exercise at three controlled speeds. Bipolar surface electrodes with standard placement were employed throughout the study. Eleven volunteer college women performed three trials at each speed. All Ss were familiar with the exercise and the test procedures. Angles and hand grip were kept constant. Randomization of speed of contraction eliminated order effects, and no verbal motivation was provided. Rest was controlled to negate fatigue. An analysis of variance (ANOVA) and Duncan's Multiple Range Test were used to determine the significance of any differences obtained. Results indicated that the slower the speed of movement the greater the MAP output. In every instance, each slower speed produced a significantly greater MAP (P greater than .01) than the compared faster speed, except for the biceps brachii which exhibited the same trend but with no significance for the moderate speeds. (Author/JB)