From hitting rapids indoors to chuteless skydiving, simulators give access to activities inaccessible to some.

For many athletes, finding the time and place to train isn't always easy. Golfers have driving ranges. Baseball players have pitching machines. But what about more extreme sports like kayaking?

It's not always easy to find rapids for a quick workout after work. So a pair of inventors created a device that uses two industrial pumps and churns out 6,400 gallons of water per minute to simulate white water in a small pool. Kayakers can practice all sorts of moves. The setup costs $60,000.

Rock climbers have used artificial walls to hone their skills for years. Indoor climbing walls also offer climbers a way to strengthen muscles without worrying about weather or severe falls. Those artificial walls, however, are getting more high tech: Many now work like a treadmill, rolling up new terrain for climbers.

For skiers, there's a device called Ski Trac, a 175-meter rotating snowfield that's completely enclosed. It is a constantly moving snow deck that allows skiers to ski in place for hours on end. Right now it's just a concept. A small model was built in Australia to see if the idea would work, and the concept has generated worldwide interest.

Las Vegas is home to a skydiving simulator that allows jumpers to practice their tricks without ever opening a parachute. It works by blowing air from the bottom of a chamber, keeping aloft jumpers wearing special suits.

A little imagination -- and great advances in technology -- are allowing all sorts of athletes to participate and excel at sports they'd otherwise have to sit out.