PAC POWER HOUR
Phase 2: Develop full body strength, muscle, and balance all with little impact to the joints. Constant movement via the trampoline and little rest time between exercises, make this not only an effective form of strength training, but also a functional form of cardiovascular exercise.
Monday & Wednesday 7 - 8 AM
The Physics of Rebounding
By Nolan McSheridan
Train smart, and hard.
Lets get right down to it - Rebounding is a form of training that isn't so commonly seen in the vast family of training exercises. As with most things, with some education and evidence of results, that just might change.
Its important to approach training not merely as a physical discipline based in vanity, guided by superficial/generic information. Most of us know we need to lift some weight, and elevate our heart rate to get desired results; the specifics of how we perform these activities generally doesn't matter that much. Rebounding differs from these common forms of resistance training in a few ways that are quite unique.
Rebounding (jumping up and down on a trampoline) is a mechanical demonstration of the most basic laws of physics. The repeated bouncing is a textbook example of the Conservation of Energy, from potential to kinetic.
All objects that are moving have kinetic energy. Kinetic energy, simply put is the energy an object with mass moving with some velocity possesses due to motion. As a person bounces on a trampoline, their kinetic energy changes with their velocity. Kinetic energy is peaked just before impact, and as the body leaves the surface on it's way up. Kinetic energy is null at the height of the jump, just prior to descent; and after impact, when the body is about to be propelled back upwards.
Like kinetic energy,
Potential Energy also changes while rebounding. Potential energy is the
energy an object possesses relative to its position, not motion. The
position being the height of the body during rebounding. The higher the
body goes, the more potential energy it has, and as the body travels
upward, kinetic energy decreases. Similarly, as the body descends,
potential energy is decreased.
This conveyance of energy demonstrates beautifully the law of Conservation of Energy, a principle that states that energy cannot be created or destroyed, but can be altered from one form to another.
So beyond just being a cool demonstration of physics, how does this information tie in to make rebounding unique and potentially more effective then general resistance and cardio training?
Bouncing on a trampoline combines three natural forces repeatedly: acceleration, deceleration, and gravity.
Accelerating upwards the body begins to slow down and reaches the peak of its jump due to gravity. Without gravity, the body would continue its upward trajectory. At the peak of the jump, just prior to descent, the body is in a state of “weightlessness”. Then the body begins to fall, accelerating back to earth, eventually making impact with the mesh of the trampoline. At the point of deep impact, the body experiences a G-force of 2-3 Gs. The acting G-force on earth's surface is approximately 1 G, and it is this force that determines how much we weigh. Moreover at the point of impact, the body for a fraction of a second is subject to forces as if it weighed 2-3 times its weight at 1 G. This exposure to greater levels of G-force is what strengthens the body. Grasp dumbbells and this effect is further amplified. Rebounding is the only exercise that allows the body to repeatedly experience these forces, and while the benefits of such training have clear benefits for the musculoskeletal and cardiovascular systems; most interesting is that EVERY cell in the body is forced to react and adapt to the changes these forces enact on the body. This serves to strengthen the body on a cellular level, and is what sets rebounding apart from traditional forms of exercise. More research is needed to speak definitively on the impact this has for cellular function, but a form of exercise that actually works upon every cell in the body, with potential to slow premature cellular termination and strengthen against possible cellular dysfunction, is certainly worth the attention - and hopefully, future research.
To put it simply, resistance training is done solely for the purposes of strengthening the body to hold up against the forces of gravity, and to move objects with greater mass against gravity with more ease. Therefore it certainly makes sense to train the body in such a way that utilizes these these forces to our advantage, with the benefits extending to every cell in our body.
Talk about getting more bang for your bounce! Thanks for reading and stay tuned for more benefits of incorporating Rebounding into your exercise and health routine!
- Nolan McSheridan