As far as “racing”, I said an air rowing machine is better because the Concept2 is the only model used for indoor rowing competitions, setting world records, and entering your actual scores online. It is because their monitor can calculate the drag factor of the flywheel in real time and accurately calculate distance and time. Small changes such as dust build up, air temperature, and humidity will not change the times between different machines because the drag factor is calculated every stroke.
HIIT (High Intensity Interval Training) is a great style of training to burn fat, build toned muscle, and improve cardiovascular systems as the same time. Challenging HIIT workouts help you get to that state of EPOC and take advantage of the after-burn effect. The ability to change the resistance of the rowing machine at will means that the equipment is ideal for this method of exercise.