For weightloss or strength training I don't think it's that great of an investment but I use my needak rebounder for other very important reasons, mostly cellular. The cheaper trampolines are not to be used for them because of the inferior springs that are used.
Here is the best description of the benefits. I've copied these from the needak website
http://www.needakmfg.com/ I suggest you go there for more info :
How Rebound Exercise Accomplishes Its Benefits
Rebounding involves aerobic movements performed on a bouncing device that looks like a small trampoline. It has you jumping up and down for health and fitness. As an ideal jumping device, the mini-trampoline or "rebounder," has a strong woven mat attached by coiled steel springs to a circular steel frame. The rebounder usually is round, although some models have been made oval, rectangular, square or polygonal. The entire jumping surface of the mat is twenty-eight inches in diameter, stands on six legs with spring coils of their own, which are seven to nine inches high.
Sometimes, for people who feel unsteady on their feet or for the elderly, handicapped, and disabled, a stabilizing bar may be added to the rebounder's frame (see Photograph 2). It's attached to two of the frame's legs so that the individual needing more security can hold onto this bar and still bounce aerobically.
Photograph 2. Shown is the NEEDAK® Soft Bounce™ rebounder with a stabilizing bar attached. This bar offers those who feel unsteady on their feet a greater sense of security while rebounding.
In jumping on a well-made rebounder, the exerciser usually feels invigorated and filled with a sense of well-being. People who rebound find they're able to work longer, sleep better, and feel less tense and nervous. The effect is not just psychological, because the action of bouncing up and down against gravity, without trauma to the musculoskeletal system, is one of the most beneficial aerobic exercises ever developed.
Rebounding aerobics is working with gravity to cleanse your tissue cells and act as an oxygenator, which, in turn, lightens the load on the heart. Also it's fun to bounce! Much more than fun, however, rebounding provides a number of physiological pick-me-ups for the person who sustains this activity for at least ten minutes, four times a day, or for a single daily session for 40 minutes. As you bounce, your feet hit the mat with twice the force of gravity. Then just as the astronauts experience while floating in space, your body is in a state of weightlessness at the top of the bounce.
Jumping on the mini-trampoline is remarkably un-strenuous on the Joints. There's no solid ground to suddenly stop the bouncing of your feet. Your movements are perfectly safe, and they make the effect of gravity beneficial. By working against constant gravitational pressure while bouncing, you resist the Earth's pull. Your resistance is subtle, but it builds cellular strength. Rebounding's alternating weightlessness and doublegravity produce a pumping action which pulls out waste products from the cells and forces into them, oxygen and nutrition from the bloodstream.
Jumping's Oxygenating Effect
If you have a resting heart rate of less than 60 beats a minute, don't smoke, don't have chest pain, live a healthful lifestyle, and engage in rebounding for 40 minutes or more each day, at least five days a week, theoretically it's not likely that you'll ever develop a heart problem if you have none now. Jumping on a rebounder helps you to attain your heart rate target zone every day that you rebound for the recommended 40 minutes.
Rebound exercise strengthens your heart in two ways: It improves the tone and quality of the muscle itself, and it increases the coordination of the fibers as they wring blood out of the heart during each beat. The aerobic effect while you are rebound-jumping equals and often surpasses that of running.
Your rate of rebounding will vary, depending on how vigorously you bounce and how high you lift your feet off the mat. Rebound exercise offers the ideal aerobic effect with almost any rate of performance, because it fills all the requisites of an oxygenating exercise. Rebounding might be considered a precursor movement for better achieving the oxygen therapies.
The Detoxification Effect of Rebounding
The lymphatic system is the metabolic garbage can of the body. It rids you of toxins such as dead and cancerous cells, nitrogenous wastes, fat, infectious viruses, heavy metals, and other assorted junk cast off by the cells. The movement performed in rebounding provides the stimulus for a free-flowing system that drains away these potential poisons.
Unlike the arterial system, the lymphatic system does not have its own pump. It has no heart muscle to move the fluid around through its lymph vessels. There are just three ways to activate the flow of lymph away from the tissues it serves and back into the main pulmonary circulation. Lymphatic flow requires muscular contraction from exercise and movement, gravitational pressure, and internal massage to the valves of lymph ducts.
Rebounding supplies all three methods of removing waste products from the cells and from the body. Then arterial blood enters the capillaries in order to furnish the cells with fresh tissue fluid containing food and oxygen. The bouncing motion effectively moves and recycles the lymph and the entire blood supply through the circulatory system many times during the course of the rebounding session.
Rebounding is a lymphatic exercise. As stated earlier, it has the same effect on your body as jumping rope, but without any jarring effect to the ankles, knees, and lower back that comes from hitting the ground. Better than rope jumping, however, the lymphatic channels get put under hydraulic pressure to move fluids containing waste products of metabolism around and out of the body through the left subclavian vein.
Rebounding's Stabilizing Effect on the Nervous System
Bouncing on a rebounder is an excellent method of reducing stress. It can put the bouncing person into a trance like state and totally relax him or her. Jumping for health and fitness not only stabilizes the nervous system during the exercise period, but continues to help maintain equilibrium after one steps off the device. The result is increased resistance to environmental, physical, emotional, and mental stress. It may possibly help an individual to avoid psychosomatic disease and mental or behavioral instability.
Rebounding may be enjoyed for a lifetime and adjusted to your own particular level of fitness. It is safe, convenient and inexpensive, and its protective effects against degenerative diseases make it one of the most effective forms of motion in the work place, in recreational pursuits, or in simply exercising for the care of your body and mind.
The Physical Muscular Effect of Rebounding
James White, Ph.D., director of research and rehabilitation in the physical education department at the University of California at San Diego (UCSD), has explained how jumping for health offers a true physical strengthening effect to the muscles. He said, "Rebounding allows the muscles to go through the full range of motion at equal force. It helps people learn to shift their weight properly and to be aware of body positions and balance."
An advocate of rebounding for athletic conditioning, Dr. White uses the rebounder in his rehabilitation program at UCSD. "When you jump, jog, and twist on this (jumping) device you can exercise for hours without getting tired. It's great practice for skiing (see Photograph 9), it improves your tennis stroke, and it's a good way to burn off calories and lose weight," said Dr. White (see Table A). "My students tell me it's so much fun that they often exercise on the rebounders for their own enjoyment."
Dr. White added that jumping for health is more effective for fitness and weight loss than cycling, running or jogging (see Table B), and it has the added advantage of producing fewer injuries.
As illustrated and explained in my book, Jumping for Health, there are 33 different exercises that may be performed advantageously on the rebounding device. Eight popular rebound movements are shown below (see Photographs 3, 4, 5, 6, 7, 8, 9 and 10).
The gentle bounce of rebounding is effective in returning natural, regular bowel movements to chronically constipated persons. The steady bounce sets up a pulsating rhythm transmitted by the nervous system to the brain area responsible for regulating the intestinal system, which reestablishes one's rhythmical bowel activity. Digestion is improved as well.
EmC
