136 bpm during 5 minutes

140 bpm during 5 minutes

142 bpm during 5 minutes

142 bpm during 2 minutes

The musical cadence for the basic aerobic steps performed with the Kangoo Jumps is:

120 bpm during the whole exercise.

The first part of the exercise is made without Kangoo Jumps, during 16 minutes.

Every 2 minutes a new step is engaged. After the end of the first exercise, the same base steps are repeated in the same sequence, for 16 minutes , with Kangoo Jumps.

STEPS
The basic aerobic steps studied were:

1. Jogging in place (arms low)

2. Jogging in place (arms lifted)

3. Jogging (forward, backward)

4. Grape Jump

5. Jumping Jacks ? 4

6. Kick (low)

7. Jumping Jacks ? 2

8. Knee ups

RESULTS
The charts and graphs that follow this report show the average cardiac frequencies (CF) of each subject for each step. In order to check if the differences of CF between "KA" and "SA KA", smaller than 5, are not due to the stagnation of the CF, characteristic to subjects attaining their CF maximum, the CF obtained by each subject at each step is represented according to the CF maximum of each subject. The increase of the CF related to the effort tends to diminish when values reach the threshold anaerobe of the subjects.

DISCUSSION
In general, it is less economic to execute basic steps with Kangoo Jumps than without. This difference is about 10 beats/minute, and varies, according to the step, from 6 to 17 beats/minute. The difference of CF is increased for steps 4, 6 and 7. Only a slight difference is found between basic steps 1 and 2. Moreover, the two latter steps have no high energetic cost (from 137 to 150 beats/minute). Also, the subjects are far from their CF max. (75% for step 1 and 79% for step 2, see table 1). This difference is principally due to male subjects (subjects 2 and 3). Both of them obtain a negative difference. It would be interesting to study, in greater detail, this difference in order to determine if the "sex factor" clearly influences the results for these two steps.

Step 5 requires a lot of energy, with or without Kangoo Jumps. Despite the relatively high value, between 82% and 99%, the average difference is only of 4%, which can be explained by the fact that the values (beats/minute) that are near the CF maximum of each subject have reached the highest point.

Subject 1 had, on an average, 18 more beats/minute with Kangoo Jumps, which represents the highest difference among all subjects. On the other hand, subject 3 only obtains a difference of 5 beats/minute. Indeed, this subject is less economic without Kangoo Jumps for steps 1, 2 and 3.

The highest variation of CF between both ways of executing the steps are also observed with subject 1. This difference is of 30 beats/minute for basic step 6. Such a difference could be explained by the lack of experience using Kangoo Jumps. Subject 2 has 26 more beats/minute with Kangoo Jumps for step 4, which is rather high, but the factor "beginner" cannot be applied to this subject, because the average that was obtained for all basic steps is only of 9 beats/minute.

Note that the exercise was executed uninterruptedly, which may have influenced the beats for the following steps. Though, for the 4 last steps, we obtain relative values higher than 80%. Another study that would reverse the steps? order, would permit us to determine if the results of the study are influenced by the order itself.

Chérif Zouaoui, January 1998