As swimmers advance, kickboards can help develop strength. Swimming is a multitasking sport. It uses breathing, arms, body position and kick.
A kickboard takes the arms and sometimes the breathing out of the equation, allowing a swimmer to focus on isolating the large muscle groups in the legs that do the majority of the work of kicking.
It also takes away the assistance of the upper body and adds the resistance of the floating board, which makes the legs work even harder. But remember not to rest your weight on the kickboard or lift your body out of the water -- that can start a bad body position habit that's hard to break.
Kickboards aren't just for beginners or athletes in training -- they're for anyone in the water at any level. If you keep your body position in mind, kickboards can be a valuable part of your workout. Swimmers of any level, and even non-swimmers, can use a kickboard as part of a rehabilitation workout. It's a low-impact exercise that's easier on your joints than other sports, such as running, basketball or tennis. Among swimmers, shoulder injuries are fairly common. Kickboards allow the joints to rest while keeping up a water workout.