The Challenge AR features an advanced computer monitor providing the rower with measurable performance output, an ergonomically designed seat that rides on precision bearings and rollers for absolute smoothness, an upgraded footboard with advanced heel support, and an innovative soft grip handle to eliminate stress on the hands and wrist during the comfortable, but physical workout.
* While there is nothing to adjust from row to row on the WaterRower, it is possible to increase or decrease the level of resistance by changing how much water you put in the drum. The monitor is pre-calibrated to match 17 liters of water, but you can change that if you want. More than 17 liters = more resistance, up to the max fill line. This is not something you'll want to change frequently, it's more of a set-it-and-forget-it thing.
There are many differing sets of rules governing racing, and these are generally defined by the governing body of the sport in a particular country—e.g., British Rowing in England and Wales, Rowing Australia in Australia, and USRowing in the United States. In international competitions, the rules are set out by the world governing body, the Fédération Internationale des Sociétés d'Aviron (FISA). The rules are mostly similar but do vary; for example, British Rowing requires coxswains to wear buoyancy aids at all times, whereas FISA rules do not.
However, I own an air rower and have zero worries about maxing out it’s ability. I can completely exhaust myself on any type of workout. Air and water rowers are the chosen resistance type by Olympic athletes and any athlete looking to train their full-body cardio. I don’t think they would choose this resistance type if they felt they could max it out.
At the junior level (in the United States), regattas require each rower to weigh in at least two hours before their race; they are sometimes given two chances to make weight at smaller regattas, with the exception of older more prestigious regattas, which allow only one opportunity to make weight. For juniors in the United States, the lightweight cutoff for men is 150.0 lb.; for women, it is 130.0 lb. In the fall the weight limits are increased for women, with the cutoff being 135 lb.
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.