Hydro-Bells are a yellow hydrodynamic resistor with three-dimensional configurations designed to enhance and take advantage of the total resistance field of water. Bells can be rotated 90 degrees to change the resistance from medium to maximum by changing the drag surface area.
This principle allows students to adjust an exercise to meet their specific strength limitations and/or their exercise goals. You might start some warm-up moves with the bell turned to move through the water with less resistance at first and then turn the bell to go through the same movement with increased resistance. Additionally, you can work at higher speeds for a movement with the bell turned in the direction of less resistance. Since there are both fast and slow twitch muscle fibers you might want to work at various speeds to develop both types of fibers during your workout.
Since you are ultimately in control of the resistance based on your input, these bells are adaptable for all levels of fitness.