Hines recommends that those with health issues first consult their doctor or health professional to make sure it’s the right exercise for them, as jumping on a trampoline or rebounder can be a strenuous activity for some. “When it comes to rebounding, people with chronic conditions with their knees, vertebrae, or discs should use an extra dose of caution before they start, and so should people who have a history of concussions or head injuries (those g-forces affect the entire body, from head to toe),” says Hines. Additionally, children should always be supervised when using a rebounder or fitness trampoline.