Elastic Band Prediction Equations for Combined Free-Weight and Elastic Band Bench Presses and Squats

Abstract

Elastic bands added to traditional free-weight techniques have become a part of suggested training routines in recent years. Because of the variable loading patterns of elastic bands (i.e., greater stretch produces greater resistance), it is necessary to quantify the exact loading patterns of bands to identify the volume and intensity of training. The purpose of this study was to determine the length vs. tension properties of multiple sizes of a set of commonly used elastic bands to quantify the resistance that would be applied to free-weight plus elastic bench presses (BP) and squats (SQ). Five elastic bands of varying thickness were affixed to an overhead support beam. Dumbbells of varying weights were progressively added to the free end while the linear deformation was recorded with each subsequent weight increment. The resistance was plotted as a factor of linear deformation, and best-fit nonlinear logarithmic regression equations were then matched to the data. For both the BP and SQ loading conditions and all band thicknesses tested, R values were greater than 0.9623. These data suggest that differences in load exist as a result of the thickness of the elastic band, attachment technique, and type of exercise being performed. Facilities should adopt their own form of loading quantification to match their unique set of circumstances when acquiring, researching, and implementing elastic band and free-weight exercises into the training programs.

Volume estimations for combined free-weight and rubber-band resistance exercise

“…This underestimate is further exaggerated at lower band lengths when the loading curves are steeper. Given the range of band lengths that are likely to be encountered with combined loading, error could be significant according to the published band length deformation curves (Mcmaster, et al, 2010;Shoepe, et al, 2010). Overestimation would therefore be more pronounced in lifters of a smaller stature and results in sex specific differences in volume estimation where women would likely encounter a greater error than men on average.…”

“…Previous work (Shoepe, et al, 2010) experimentally calculated the loading properties of a set of rubberbands such that for a given length of band (x), the force applied can be calculated as a function of x. This set of regression equations as experimentally determined is shown in Table 1.…”

“…* x = linear band deformation in meters, y = resistance applied in kg, ln = natural log, from Shoepe, et al (2010).…”

“…Continuing, these values a=c 3 h=0.514h, b=c 4 h=0.866h for men and a=c 3 h=0.52h, b=c 4 h=0.858h for women, and n=2 can be input into Equation 9 and reduced to: Note. h = body height of an individual in meters, m = total freeweight resistance applied in kg, ln = natural log, c 1 and c 2 = constant from elastic band specific regression equations from Shoepe, et al (2010).…”

“…This is due to traditional free-weight exercises producing linear loading patterns, whereas variable resistance, as incurred by rubber-bands, exhibit nonlinear loading patterns (McMaster, Cronin, & McGuigan, 2009;Mcmaster, Cronin, & McGuigan, 2010;Shoepe, Ramirez, & Almstedt, 2010;Thomas, Mueller, & Busse, 2005). The variable loading pattern of rubber is the result of established material properties of rubber bands, which do not follow the early-phase, elastic region of Hooke's law that includes a linear elongation-force relationship.…”