Are the tensile and pressure resistance of dumbbells, fitness studio equipment and the Isokinator comparable?

No, because every device generates individual force action for the user. This depends on various factors such as body size, joint position and leverage. This all contributes to the actual resistance value which the muscle must overcome. Thus, kilo values are always relative and cannot be compared with other kinds of equipment or individuals. It is much more important to observe the ongoing increase of personal resistance using the same device from workout to workout. In the case of an ISOKINATOR this increase is sometimes made in increments and is sometimes stepless. Average leverage is part of the equation. From the beginning to the end of every exercise movement, the device always maintains the same leverage, angle and resistance for each segment of the movement. This is the defining feature of isokinetic training. It should not be confused with isometric training, which merely involves training with motionless holding force.