Some accessories are rigged. For example, steel chairs used to smash someone's head in aren't made out of steel, but rather thin aluminum. Tables can easily break, especially when a body hits it. Even the mat has extra suspension, not only for safety, but also to exaggerate movements. For those who claim that wrestlers are not athletes, consider this.
Wrestlers work non-stop, around the year.
They travel from city to city each week to do a show. With Raw or Nitro happening the next day in a different city, one can imagine the effects of travelling continuously on the wrestlers. Wrestlers take breaks only on their own free will. Wrestlers also work hard. You may think that everything is scripted from the start, but many wrestlers have to start from the bottom of the ladder and work their way up to become a superstar.