Slipstream helps you get more out of your pool. Enjoy a gentle, non-impact exercise by walking or jogging against the adjustable speed current. When you walk against a current you are using your core to resist the flow and maintain an upright posture with your feet touching the bottom. Since water is so much denser than air you work all the muscles moving your legs through the water. Sore knees, hips, ankles can all benefit from unweighted movement.Turn it up and and you have the makings of a world-class aerobic workout.