Smooth and Flowing

Rowing, like other endurance based aerobic pursuits (such as swimming, running, cycling, skating, etc), is naturally smooth and flowing.

If endurance based aerobic pursuits are harsh and mechanical, or jerky and jarring, you are doing them wrong.

The WaterRower, like rowing, fatigues the user purely aerobically.

Conventional mechanical resistance based rowing machines fatigue mechanically as well as aerobically.

The harshness of this mechanical fatigue should not be assumed to be of any benefit, it does not change your heart rate and hence does not improve your aerobic benefit. It just hurts.

When training for endurance based exercise like rowing you are training your cardio vascular system. Hurting does not enhance your cardio benefit.