Measuring and Testing with Flywheel Resistance Training Devices

Abstract

The applied physics that explains the nature of flywheel resistance training devices highlights the importance of knowing the mechanical demands during the concentric or the eccentric phase of the movement. As shown in other isoinertial equipment, flywheel devices show a mechanical overload as the moment of inertia is increased. However, it is not easy to express the load intensity as a percentage of “something” (such as the one-maximum repetition in free weights). For this purpose, the peak acceleration can distinguish among different inertial loads and fatigue levels along with repetitions and sets. In relation, the load of a flywheel resistance training device has to be accounted for considering the shaft’s width and the moment of inertia used. A conical pulley will vary the axis and, consequently, the load, over the exercise range of motion compared to a horizontal cylinder device. On those, higher peak torque can be found. Finally, caution should be taken when monitoring the eccentric overload, that has been a topic of interest. Not all the individuals experiment an eccentric overload, and it is important to highlight that the only way to achieve eccentric overload with flywheel devices is by modifying the tempo or the range of motion during the eccentric phase.