Indoor rowing simulates the action of watercraft rowing for the purpose of exercise or training for rowing and has become a sport in its own right.
Modern devices are often known as ergometers which is calibrated to measure the amount of energy the rower uses with the equipment. Although the resistance of the machines may be adjusted they are consistent on all of them for sporting purposes.
A large number of indoor rowing competitions are held all over the world. They are organized into categories based on sex, age, and weight class. There is a nexus between performance on-water and performance on the ergometer, with open events at the World Championships often being dominated by elite on-water rowers.
In addition to live venue competitions, many racers compete by internet, either offline by posting scores to challenges, or live online races facilitated by computer connection.