Exercise ball balls have been jumped across at 8.31 seconds.The record for the farthest jump between two Swiss balls was also made by Neil at a distance of 2.3 meters in 2012 A primary benefit of exercising with an exercise ball as opposed to exercising directly on a hard flat surface is that the body responds to the instability of the ball to remain balanced, engaging many more muscles. Those muscles become stronger over time to keep balance. Most frequently, the core body muscles — the abdominal muscles and back muscles — are the focus of exercise ball fitness programs. A major
Q-ball can have an energy per unit charge that is less than formula_21, meaning that it cannot decay into a gas of individual particles. Such a region is a Q-ball. If it is large enough, its interior is uniform, and is called "Q-matter". (For a review see Lee "et al." (1992). The thin-wall Q-ball was the first to be studied, and this pioneering work was carried out by Sidney Coleman in 1986. For this reason, Q-balls of the thin-wall variety are sometimes called "Coleman Q-balls". We can think of this type of Q-ball a spherical ball of nonzero vacuum expectation value.