Calisthenics is good for you, but not so good for your garage. A garage door that frequently goes up and down and acts like it is possessed by a fitness guru is not normal, nor is it something to be trifled with. If this is exactly how your garage door is behaving, there is a reason (a few, in fact) and a way to make it stop.
Wiring on your garage door opener could definitely be the problem. Shorts in the wiring would make the door stop and start, and even get stuck halfway in either direction (up or down). Worse still is the wiring that is exposed and electrical current is jumping wires. This particular issue is often caused by gnawing rodents who found their way up to the electrical wiring and are heartily stripping it with their teeth. The wiring has to be checked and repaired or replaced by an electrician or someone who does garage door repairs regularly.
Button Is Jammed
Another probable cause of a garage door that appears to be doing jumping jacks is the control button. Either the button in the garage is jammed halfway in its up/down position or the button on the remote is jammed inward. Either one of these would cause the garage door to bounce. To fix the button in the garage, turn off the power to the garage and use a screwdriver to dislodge the button. The remote with a jammed button needs to be junked and replaced entirely or the problem will continue.
Radio Tower Frequencies
It is rare, but if you live close to a major radio tower, the radio tower's signals could be messing with your garage door's radio signals. Whenever the radio tower is sending out some major waves on a frequency similar to the one your garage door opener uses, the opener gets "confused" and the door opens and shuts. It may settle down after a bit, but if this happens a lot, you may need to select a very different sort of garage door opener.
Consult with a garage door installation expert to see what options are available to you that would help you resolve this problem. Sometimes a frequency jammer can help block the radio tower's signals and return your garage to normal, while a brand-new garage door opener may be your second-best bet. Talk to a radio expert as well, since he/she may have some solutions and/or equipment that could help too. For more information about garage door repairs, contact a professional in your area.