Today we talk about your articular cartilage (AC); the slippery stuff that lives at the ends of most bones and allows frictionless motion of your joints. AC is avascular and much thicker in the large, weight bearing joints, such as your knees, and much less so in fingers and toes. All this means that AC depends on local synovial joint fluid for nutrition and long life. 

The heart of this machine is motion, more specifically repetitive axial compression. With loading the AC is compressed, squeezing out waste and with unloading the expansion draws in the fresh synovial fluid. Thus AC loves this repetitive compression cycle and hates its counter part, SHEAR (side to side) which quickly leads to cellular demise and osteoarthritis (OA). The rowing motion is the panacea of AC and not only protective, but in my opinion therapeutic for early OA.