Aerobic endurance fitness is one of the most important physical fitness attributes for rowers. Rowers need to be able to maintain a very high level of intensity throughout their race. Another very important fitness component is anaerobic fitness, which means strength and power, and the ability to repeatedly exert a high force for the race duration. Rowers also need good flexibility, they need to have a low body fat level and it is advantageous to have a specific body size.