A universal system for monitoring activities and motions during exercise and controlling the resistance provided to a user of exercise equipment during the motions. The system having at least one sensor to detect at least one of physical parameter of the exercisers activity such as force, acceleration, and/or direction of user movements. The resistance mechanism provides an adjustable and variable resistance and a dampened response to an exerciser while the sensors monitor the forces and resulting movement of the user interface. The system provides an adjustable resistance system for exercising parts of the body having complex movements over a full range of motion such as the arms, legs, neck, wrist, ankle, and torso. The present invention is also adaptable to existing fitness equipment. The system can also provide effective resistance and damping over the range of motion in free space. The force exerted by the user on the user interface can be measured over the entire range of motion using force and position sensors.