The haptic sense provides continuous information during physical human-machine interaction. Humans can respond very quickly and effectively to such feedback, such as a driver making rapid steering adjustments when his vehicle hits a pothole. It may be possible for designers to take advantage of this interaction by providing users with well-designed haptic communications to assist in manual control tasks. In this paper, we describe an experiment conducted to test this idea. Subjects were instructed to step on a modified stair climber at a consistent workout pace while simultaneously completing a mental distraction task. They were provided with one of five different haptic communications to assist in maintaining their workout intensity level. Results show that haptic communications helped subjects step as much as 1.7% faster with as much as 3.95% more power output than without the haptic communications, although none of the communications beneficially affected velocity or power standard deviations. Four of the five communications had no significant impact on mental task performance.