Step Reebok Guidelines - Revised

The following article appeared in the June/July 1997 issue of the Reebok Alliance Newsletter.  It is reprinted with permission from the Reebok Alliance.

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Research In Action - Stepping to a New Beat

The latest on music cadence for Step Reebok

by Michele Scharff Olson, Ph.D., and Reebok Master Trainer and Step Reebok pioneer Gin Miller

Many Alliance members have been asking Reebok to revise its guidelines for the Step Reebok® Program. In particular, a number of you have requested that we endorse a more liberal standard for exercise cadence, or beats per minute (bpm). Before developing new guidelines, Reebok asked Michele Scharff Olson, Ph.D., an independent researcher of the Human Performance Laboratory at Auburn University Montgomery, to analyze seven years of step research and develop a Step Reebok Position Stand. Out of Dr. Olson's Position Stand and a careful analysis of the effects of Step Reebok exercise comes the following summation of Reebok's revised guidelines concerning exercise cadence.

Step Reebok requires gradual exercise progression for both regimen adherence and injury prevention. The four-level participant criteria (see box, "Step Reebok Exercise Prescriptive"), describes the requisite step skills and experience associated with each level and also outlines the limitations on music tempos. Participants' rates of progression should be determined by their levels of aerobic fitness, as well as their ages, health, skill levels, and individual traits, including their needs and goals.

One change at a time. The variables that affect exercise intensity-that is, increased platform height, greater arm involvement, more advanced movements, and increased step tempo-should be introduced in a linear fashion. Adding more than one variable at a time runs counter to biomechanical and physiological research findings, and does not allow a body time to adapt to the new stresses. Step exercise intensity increases approximately 7 to 10 percent between each 2-inch platform height and between the traditional step speed (118 - 122 bpm) and the fastest permissible speed (128 bpm). Therefore, changing to a higher platform and the fastest step tempo simultaneously is theoretically equivalent to increasing the platform height by two levels (4 inches), or the intensity by 20 percent. Even changing to a higher platform and the next fastest speed simultaneously results in a 12 percent increase in intensity, which is unnecessarily pronounced.

Instructors should pay particular attention to the words "up to" in the Exercise Prescriptive, which allow flexibility in an individuals' progression. For example, Advanced (Step 4) participants may continue to use an 8-inch platform in a class with a faster tempo (128 bpm), or they may move from a 6-inch to an 8-Inch platform in a class that uses a tempo of 120 bpm. The new guidelines simply provide a more versatile, yet scientifically valid, means to better satisfy the individual needs of Step Reebok participants.

Temper the tempo. Of particular importance .is the ceiling music cadence of 128 beats per minute. Both the biomechancial and physiological data collected and published from the Human Performance Laboratory and others are very clear in supporting this cap. At tempos faster than 128 bpm, the impact forces increase significantly. Novices, especially, demonstrated difficulty in absorbing the impact forces at faster speeds, compared with participants who were experienced in step.

Moreover, a definitive physiological study demonstrated that, at music tempos in the 128-bpm to 138-bpm range, lactic acid levels-which indicate high anaerobic metabolism-rise markedly. Under these conditions, more than half the female subjects in this study (who were moderately fit and had step exercise experience) could not complete a typical 20-minute step protocol due to exertional fatigue. Prior to the fatigue, their movement technique, postural alignment and proper foot positioning all suffered. Male subjects in the same study exercised at 90 percent of their aerobic capacity, which is in excess of the accepted range of the American College of Sports Medicine. Thus, there are definitive risks and few benefits for step speeds above 128 bpm.

Finally, in classes with a mixed level of participants, Step Reebok recommends that instructors encourage students to adjust platform heights for increased exercise intensity and limit the music tempo to the traditional 118-122 bpm. While research shows that step speeds between 118 - 128 bpm can be suitable across different fitness levels, the traditional 118-122 bpm tempo provides a very viable level of intensity even for very fit step exercisers. In fact, studies conducted with highly fit step instructors show that on the higher (6-, 8- and 10-inch) platforms, the 118-122 bpm speed places them between 70 percent and 85 percent of maximum heart rate.

Step Reebok Exercise Prescriptive