At the collegiate level (in the United States), the lightweight weight requirements can be different depending on competitive season. For fall regattas (typically head races), the lightweight cutoff for men is 165.0 lb. and 135.0 lb. for women. In the spring season (typically sprint races), the lightweight cutoff for men is 160.0 lb., with a boat average of 155.0 lb. for the crew; for women, the lightweight cutoff is 130.0 lb.
In the 1950s- and 1960s, more sports coaches began to use rowing machines for training and assessment of athletes' performance. One such rower developed at this time was the Harrison-Cotton machine, the brainchild of John Harrison of Leichhardt Rowing Club in Sydney and Professor Frank Cotton, produced by Ted Curtain Engineering. This was the very first piece of equipment able to measure athletic power with great accuracy, and it also imitated the actual experience of rowing more closely than any previous rowing machine.
The recovery phase follows the drive. The recovery starts with the extraction and involves coordinating the body movements with the goal to move the oar back to the catch position. In extraction, the rower pushes down on the oar handle to quickly lift the blade from the water and rapidly rotates the oar so that the blade is parallel to the water. This process is sometimes referred to as feathering the blade. Simultaneously, the rower pushes the oar handle away from the chest. The blade emerges from the water square and feathers immediately once clear of the water. After feathering and extending the arms, the rower pivots the body forward. Once the hands are past the knees, the rower compresses the legs which moves the seat towards the stern of the boat. The leg compression occurs relatively slowly compared to the rest of the stroke, which affords the rower a moment to recover, and allows the boat to glide through the water. The gliding of the boat through the water during recovery is often called run.
The rowing machine itself is unlike any other on the market with its patented water filled flywheel. It is hard to exactly copy the action of a scull on the water, but the mechanics of the flywheel spinning in water comes in a close second on dry land. The fact that the water is 800 times denser than air means that there is no need for any extra resistance or dampening that you will find in normal air rowers. The faster you pull, the more resistance is generated giving it infinite variability. However, if you want to be able to practice rowing with a faster stroke, you will have to reduce the amount of water in the tank unlike an air rower where you just have to adjust the baffle.