Machine Resistance Curve Analysis of Seven Resistance Training Machines

Abstract

Introduction: Resistance training (RT) is not only feasible but also widely recommended across a spectrum of chronic disease contexts as well as for those with functional limitations. Many RT machines incorporate mechanisms that alter the machine’s resistance curve (MRC) in an attempt to match the variable strength of the participant through a resisted ROM (RROM). Several investigations have tested this relationship using weight selections greater than what might be appropriate for targeting low to moderate training intensities. This article presents an analysis of low to moderate RT selections offered by seven RT machines. Methods: An evaluation of the MRCs of seven RT machines was performed. Three leg extension machines, two chest press machines, and two seated row machines were selected for analysis from three fitness centers in Baltimore, MD and Oklahoma City, OK. The method of analysis is described. The acquired force data were normalized and plotted in order to categorize the MRCs of each machine. Results: Four of the seven machines offered more than one MRC based on the weight selected. Conclusions: The selection of resistance on an individual machine might influence targeted factors such as participant effort or achievable RROM.