In another investigation, subjects were evaluated while performing different slide movements, including the standard, hip flexion, knee flexion and low-profile techniques. The hip flexion and knee flexion slide techniques are adaptations of the standard slide and simply required the raising of the knee (hip flexion) and bending at the knee (knee flexion) when reaching each end of the slide board (contacting the bumper).

The low profile slide was performed by markedly lowering the body and flexing the trunk so that the cross-lateral hand contacts the bumper(left hand touches right bumper, and vice versa) at the termination of each sliding pass. Compared to the standard technique, the hip flexion and knee flexion techniques increased energy cost approximately 16 percent, and the low profile technique increased energy cost approximately 28 percent. These results show that energy costs of slide board exercise can vary dramatically depending on the type of exercise maneuvers. For the above exercises, as the amount of muscle involvement increased, so correspondingly did energy cost.

Further investigation included the addition of ankle weights while subjects performed the standard slide exercise.9 Subjects wore a 7.5-pound leg weight while performing the standard slide technique. Generally, leg or ankle weights are not recommended because of increased lower-leg or ankle stress associated with high-impact exercise and running.

Because of the low-impact nature of slide board exercise, however, ankle weights may be appropriate. In this investigation, the use of leg weights increased energy cost approximately 12 percent. It was concluded that the use of leg weights can significantly increase the metabolic responses to slide board exercise.

Yet another study evaluated heart-rate responses during slide board exercise, compared to that of running on a treadmill.12 Subjects exercised at the same intensity, based upon oxygen requirement, and experienced significantly higher heart-rate response (15 percent) during slide board exercise, as compared to treadmill running at the same energy cost. The same phenomenon has been shown with women and other forms of aerobic exercise. Step testing, aerobic bench stepping, aerobic dance and stair climbing all have shown higher heart rates at the same energy cost when compared to running.3,7,11,12 These investigations suggest that the heart-rate responses of various forms of aerobic exercise may be higher than running and walking programs at similar intensity levels.