A system, for the performance of exercise, wherein the system comprises a microprocessor, a pulley, a speed sensor, a brake, a support bar, a digital panel, a steel cable, a dynamometer, a spring, and a speed selector, wherein the steel cable is attached to the pulley and connected to the support bar, and wherein the spring is attached immediately above the central axis to the pulley and, in order to overcome the resistance of the spring, a minimum force must be applied to the support bar, - based on a determination of the speed made by a user, the speed selector is configured to specify the constant rotation speed, wherein the microprocessor is configured to maintain the constant rotation speed as specified by the speed selector, - the dynamometer is configured to supply information about applied force to the steel cable to the microprocessor, - the speed sensor is configured to constantly measure an instantaneous rotation speed of the pulley and to forward said instantaneous rotation speed information to the microprocessor, - the microprocessor which based on the received information from the speed selector and on the received information from the sensors (4, 9), is configured to determine an operation of the brake of the pulley in order to maintain a constant rotation speed of the pulley, so that the speed of movement of the support bar is maintained constant, • wherein the brake acts by releasing the pulley when it rotates below the programmed speed, or • wherein the brake acts by being applied on the pulley when it rotates above the programmed speed, - wherein the brake is a disc, electromagnetic, drum or electro-hydraulic brake, - wherein the dynamometer is installed on the steel cable, and - the dynamometer configured to supply information about the applied force to the digital panel, which digital panel is configured to display the applied force. wherein the system comprises a microprocessor, a pulley, a speed sensor, a brake, a support bar, a digital panel, a steel cable, a dynamometer, a spring, and a speed selector, wherein the steel cable is attached to the pulley and connected to the support bar, and wherein the spring is attached immediately above the central axis to the pulley and, in order to overcome the resistance of the spring, a minimum force must be applied to the support bar, - based on a determination of the speed made by a user, the speed selector is configured to specify the constant rotation speed, wherein the microprocessor is configured to maintain the constant rotation speed as specified by the speed selector, - the dynamometer is configured to supply information about applied force to the steel cable to the microprocessor, - the speed sensor is configured to constantly measure an instantaneous rotation speed of the pulley and to forward said instantaneous rotation speed information to the microprocessor, - the microprocessor which based on the received information from the speed selector and on the received information from the sensors (4, 9), is configured to determine an operation of the brake of the pulley in order to maintain a constant rotation speed of the pulley, so that the speed of movement of the support bar is maintained constant, • wherein the brake acts by releasing the pulley when it rotates below the programmed speed, or • wherein the brake acts by being applied on the pulley when it rotates above the programmed speed, - wherein the brake is a disc, electromagnetic, drum or electro-hydraulic brake, - wherein the dynamometer is installed on the steel cable, and - the dynamometer configured to supply information about the applied force to the digital panel, which digital panel is configured to display the applied force. - based on a determination of the speed made by a user, the speed selector is configured to specify the constant rotation speed, wherein the microprocessor is configured to maintain the constant rotation speed as specified by the speed selector, - the dynamometer is configured to supply information about applied force to the steel cable to the microprocessor, - the speed sensor is configured to constantly measure an instantaneous rotation speed of the pulley and to forward said instantaneous rotation speed information to the microprocessor, - the microprocessor which based on the received information from the speed selector and on the received information from the sensors (4, 9), is configured to determine an operation of the brake of the pulley in order to maintain a constant rotation speed of the pulley, so that the speed of movement of the support bar is maintained constant, • wherein the brake acts by releasing the pulley when it rotates below the programmed speed, or • wherein the brake acts by being applied on the pulley when it rotates above the programmed speed, • wherein the brake acts by releasing the pulley when it rotates below the programmed speed, or • wherein the brake acts by being applied on the pulley when it rotates above the programmed speed, - wherein the brake is a disc, electromagnetic, drum or electro-hydraulic brake, - wherein the dynamometer is installed on the steel cable, and - the dynamometer configured to supply information about the applied force to the digital panel, which digital panel is configured to display the applied force.