Investigating New Variables in Exercise and Strength Training (I.N.V.E.S.T.)
Faculty: Todd C. Shoepe, Hawley Almstedt and David Ramirez
Abstract: Elastic bands added to traditional free weight techniques have become a part of suggested training routines focusing on improvements in muscular strength and power production in recent years. Because of the variable loading patterns of elastic bands (i.e. greater stretch produces greater resistance) it has become necessary to quantify the exact loading patterns of bands. This information could then be used to properly prescribe intensity, work, and volume incurred by individuals of varying limb lengths performing squats (SQ) and bench presses (BP).
Purpose: To determine the strain and resulting stress properties of multiple sizes of commonly used elastic bands in order to accurately quantify the resistance applied to a free weight plus elastic resistance band SQ and BP.
Methods: Five commonly used 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 weight increment. This procedure was performed once with the band tied to the support as would occur with SQ and once with the band doubled over the support as would occur with BP. The resistance was plotted as a factor of deformation and best fit regression equations were then matched to the data.
Results: With displacement as the dependant variable so that limb length could then be input as the unknown displacement variable at a later time, logarithmic regression equations revealed the highest degree of correlation and all bands across both testing conditions revealed R2 > 0.962.
Conclusions: The quantification of load is critical to goal-based exercise prescription. Using these prediction equations in conjunction with the individualized anthropometrics of the participant gives a practitioner exact knowledge of the volume of exercise during combined elastic band plus free weight exercise. For example: it can therefore be ascertained that a person with a bench press reach of 1.9 m (x) will incur a black band load of 41 kg (y) at the conclusion of the concentric phase. This can be integrated with additional free weights as needed to match the desired velocity and intensity of training.