Rebounding is a form of aerobic exercise that emerged nearly
50 years ago (1). A
modern-day version of rebounding may now be seen
in fitness clubs throughout the United States.
This form of group-led exercise appears to provide
an adequate stimulus for improving and maintaining
cardiovascular fitness, and it may also be a good
choice of exercise for clients needing a low-impact
option. Rebounding involves performing basic physical
movements, similar to traditional aerobic classes,
on a mini-trampoline device referred to as a rebounder.
Although
rebounding is not new to the fitness world, it has changed since
its debut. It now incorporates more contemporary arm and leg choreography
to music, as well as a different rebounding performance style. Early
rebounding technique can be characterized as running and bouncing
movements that recoil upward from the rebounder. The present-day
rebounding method involves less upward motion and more of a downward
push of the legs onto the rebounder. This pushing movement limits
the amount of upward propulsion, while increasing the amount of
physical work being performed by the legs. The upper-body limbs
perform various bilateral and unilateral movements, such as flexion
and extension of the arm and forearm in the sagittal, horizontal,
and frontal planes.
The physiological benefits of this contemporary
rebounding program are not known. In addition,
a comparison of rebounding with other modes of
exercise has not been investigated. Therefore,
we assessed the cardiovascular responses of rebounding
and treadmill exercise performed at the same level
of perceived exertion.
Our
Project
A group of 10 trained men and women who were participating in 30 minutes
or more of aerobic activity, 3 times a week, volunteered (see
Table 1). (Data sponsored in part by a grant from QVC. Inc.)
Method of Exercise Testing
Two different exercise sessions were used. Participants
learned the proper techniques of each movement
to be performed on the rebounder. All instruction
was provided and demonstrated by a certified fitness
professional, who taught subjects the routine
and led them during the rebounding session. This
routine incorporated several different movements
including basic double-leg rebounding with hands
on the hips, 90° bent-arm chest flies with
double-leg rebounding, military presses with double-leg
rebounding, jumping jacks, double twists, and
alternating y 1||| stride moves. This familiarization
period continued until each exerciser was comfortable
performing the movements. The participant was
then given a 10-minute rest period before beginning
the exercise sessions. During this period the
Borg's Ratings of Perceived Exertion (RPE) scale
was reviewed (3).
The
first exercise bout involved rebounding for a period of 10 minutes
following the standardized instruction format led by the certified
instructor. This consisted of performing each of the rebounding
moves described above for 16 repetitions, and continually rotating
through the sequence for the length of the session. The music accompaniment
was set at 126 beats per minute (BPM). This session was followed
by a 10-minute seated rest period before beginning the second 10-minute
exercise bout. To best equate the starting physiological parameters
of exercise for both bouts, the participants remained resting until
oxygen consumption percentage for participants was 18 for the female
participants values of the first trial were attained. The second
bout consisted of a self-paced treadmill-jogging period that participants
were classified as being in the Superior" category matched
each subject's rebounding RPE. The treadmill was set at a 3% grade
and the subjects self-selected the speed in order to effectively
match the same level or intensity perceived on the rebounder. The
treadmill exercise was also accompanied by music set at 126 BPM.
Oxygen
consumption (VO2), Ventilation (VE), and respiratory exchange ratio
(RER) were measured continuously and averaged across every 15 seconds
throughout the sessions. Heart rate (HR) was taken every 30 seconds
and then averaged. RPE on the rebounder was measured every 3 minutes
and then averaged ror the session.
What
We Found
The participants in this study had body fat percentages below established
norms (2). The average body fat percentage
for participants was 18% for the female participants and 13.6% for
the male participants. VO2max values for all participants were classified
as being in the "Superior" category based on age and gender
(2) (see Table 1).
Cardiovascular
and Caloric Expenditure
The
data showed comparable cardiovascular results between and treadmill
exercise at the same level of perceived exertion (see
TabIe 2). There was no significant difference in VO2 and HR
between the rebounder and the treadmill. The heart rate response
or subjects averaged 81% or HRmax for rebounding and 82% or HRmax
for treadmill exercise. The oxygen consumption response of subjects
averaged 63% of VO2max reserve for rebounding and 66% of V02maxR
for treadmill. There was no significant difference in energy expenditure
between the rebounder and the treadmill. Rebounding yielded an average
of 9.45 ± 1.75 Kcals/min as compared to 10.07 ± 3.0
Kcals/min on the treadmill.
Discussion
The results indicate that V02, HR, and energy expenditure were all
very comparable between the two exercise modalities. Rebounding exercise
meets the American College of Sports Medicine (ACSM) Guidelines (4)
in several categories, notably that it produced HR intensities between
55% and 90% of maximal HR, which are necessary for improvement of
cardiorespiratory fitness. Rebounding exercise attained this recommendation
(81 of HRmax), indicating that improvement and maintenance of cardiorespiratory
fitness can be achieved with rebounding exercise. ACSM recommends
aVO^ intensity of 40 to 85 of maximum oxygen uptake reserve (VO2maxR)
for cardiorespiratory improvement, which rebounding exercise also
produced (63% ofVO2maxR).
The
kilocalorie expenditure averaged 9.45 Kcals/min, which was similar
to the treadmill energy expenditure of 10 Kcals/min. ACSM (4) recommends
a target range of 150 to 400 Kcals of energy expenditure per day
in physical activity for overall health benefits. Therefore, if
rebounding were performed for a minimum of 16 minutes it would meet
the lower threshold of this recommendation.
A desirable
weight-loss program usually includes a caloric restriction component
in addition to an exercise component. ACSM (4)
recommends participation in an exercise program that promotes a
daily caloric expenditure of more than 300 Kcals. This suggests
that rebounding for 32 minutes or more will meet this recommendation
for most individuals.
The
similarity in caloric expenditure between rebounding and treadmill
exercise can be explained by the use of RPE as an exercise intensity
control variable between the two modes of exercise. These data suggest
that participants were able to reproduce a similar exercise intensity
on the treadmill compared with rebounding exercise by using only
a subjective rating of their physical effort. This is worth noting
because of the belief that RPE may be mode-specific, meaning that
it may be difficult for the exercising individual to march a given
exercise intensity between different exercise modes. In light of
this finding, rebounding exercise appears to elicit a similar caloric
expenditure at a matched RPE as treadmill exercise, without exposing
individuals to impact forces experienced on the treadmill.
It
has been estimated that 80% of aerobic-related injuries are caused
by overuse and microtrauma associated with the repetitive impact
forces inherent in most aerobic techniques (5).
Rebounding may help to reduce injuries commonly related to other
forms of exercise such as jogging. One benefit of rebounding is
that the rebounder absorbs and decreases the amount of impact sustained
by the joints. This decreased force may be beneficial in preventing
overuse injuries such as shin-splints and tendonitis caused by repetitive
force, as well as helping to reduce the possibility of incurring
an exercise-related stress fracture. Thus, rebounding may be an
appropriate alternative for individuals who have joint problems
or have been told to avoid high-impact activities.
One
final observation of rebounding exercise pertains to the choice
of movements. Although rebounding choreography tends to use some
single-leg impact moves such as running and step kicks, the highly
fit participants in this project found those moves to be somewhat
awkward to perform. Therefore, acknowledging the limitations of
this project with 10 highly fit subjects, it still seems prudent
to recommend choreography on the rebounder that involves predominantly
a double-leg impact style.
Implementation
Rebounding can readily be incorporated into a
fitness routine for most physically active people.
It may be used as an alternative to regular workouts
and may be beneficial in attracting clients who
might choose not to otherwise participate in aerobic
classes. It may also be useful when attempting
to avoid overuse injuries or when combating exercise
boredom. Many movements can be added to make
the exercise more sport-specific. For example,
side-to-side hops mimic movements found in skiing.
Another option would be to include rebounding
in circuit training or cross- training programs.
Benefits
Benefits of rebounding include increased cardiorespiratory
fitness levels, caloric expenditure, and possibly
improved kinestheric awareness. Rebounding is
a low-impact physical activity. This low-impact
benefit may be beneficial in reducing overuse
injuries, which are often associated with other
types or exercise such as logging and running.
Rebounding
program and equipment resources Colleen A. McGlmie, B.S., is currently pursuing an M.S. in
Exercise Science and. Sports Administration at the University of
New Mexico. Her research interests include modality testing/comparison
and muscular strength and conditioning. She is ACSM Health/Fitness
Instructor, and NSCA Physical Trainer certified.
Len
Kravitz, Ph.D., has a doctorate in health promotion and exercise
science. He is an Assistant Professor and Researcher at the University
of New Mexico, where he serves as the Coordinator of Exercise Science.
Kravitz was recently au'arded the Canadian Fitness Professionals
"International Presenter of the Year" award.
Jeffrey
M. Janot, Ph.D., EPC, is an Assistant Professor of Exercise
Physiology in the Department o fHPER & Athletics at South Dakota
State University. Currently, his research focuses on the cardiovascular
responses during exercise in healthy and clinical populations, body
composition in special populations, and fitness product testing.
Dr. Janot is also ACSM Exercise Specialist® certified and Exercise
Physiologist certified from the American Society of Exercise Physiologists.
1.
Walker, M. Jumping for Health. Garden City Park, NY: Avery Publishing
Group, 1989.
2. Heyward, V.H. Advanced Fitness Assessment d^ Exercise Prescription.
3rd edition. Champaign, IL:Human Kinetics, 1998.
3. Borg, G. Perceived exertion: A note on history and methods. Medicine
^y Science in Sports e^r Exercise^ 6(2):90-93, 1983.
4. Balady, G.J., K.A. Berra, L.A. Golding, et al. ACSM'S Guidelines
for Exercise Testing and Prescription, 6th ed. Baltimore: Lippincott
Williams & Wilkins, 2000.
5. Mutoh, Y., S. Sawai, Y. Takanashi, et al. Aerobic dance injuries
among instructors and students. The Physician and Sportsmedicine 16(2):81~83,
1988.
Condensed
Version and Bottom Line
This study indicates that rebounding may be considered a good exercise
mode for improving aerobic fitness and for inclusion in weight management
programs. It may also be an alternative for people who may need to
stay away from traditionally high-impact activities such as running
and other styles of impact aerobics. This fitness alternative can
be easily worked into the fitness routines of clients with varying
fitness levels and abilities. For those looking for a nontraditional
way to spice up a routine, rebounding may be the answer.
