A gear is a rotating circular machine part that has cut teeth or inserted teeth, which mesh with another toothed part to transmit torque and speed. Gears can change the speed, torque, and direction of a power source, and they can produce a change in torque through their gear ratio, which creates a mechanical advantage. Two or more meshing gears, working in a sequence, are called a gear train or a transmission. Gears are used in many machines, including bicycles, motorcycles, and cars, to transmit power from the engine to the wheels. The term "gear" in these machines refers to a gear ratio rather than an actual physical gear.
In bodybuilding, the term "gear" refers to supplements, protein powder, steroids, and other products that improve the bodybuilding process. These products can increase muscle mass, strength, and workout performance. However, their use is controversial, and some bodybuilders are strictly against it.
A video on Radwell TVs YouTube channel provides a visual explanation of gears and how they work.
