The attentional focus of an individual can influence performance and physiological outcomes during strength training exercises. However, prior research has largely investigated this issue with male participants performing a biceps curl exercise and has not investigated the full range of attentional focus strategies. In the present experiment, 24 females did a sit-up exercise while adopting an associative or dissociative strategy of attending to cues that were external or internal to result in four conditions: external association, internal association, external dissociation, and internal dissociation. The external association condition produced the lowest electromyographic activity of the abdominal muscles, the lowest heart rate, and the greatest range of movement. The internal dissociation condition produced the lowest level of exercise satisfaction. The results suggest that a focus on the effects of muscle action is the most economical and least strenuous way to exercise with sit-ups and similar forms of exercise.