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

Shoepe, Todd C; Ramirez, David A; Almstedt, Hawley C

Journal of Strength and Conditioning Research: January 2010 - Volume 24 - Issue 1 - p 195-200
doi: 10.1519/JSC.0b013e318199d963
Original Research
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Shoepe, TC, Ramirez, DA, and Almstedt, HC. Elastic band prediction equations for combined free-weight and elastic band bench presses and squats. J Strength Cond Res 24(1): 195-200, 2010-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, R2 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.

Human Performance Laboratory, Department of Natural Science, Loyola Marymount University, Los Angeles, California

Address correspondence to Todd C. Shoepe, tshoepe@lmu.edu.

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Introduction

In the perpetual endeavor to improve the efficiency of training routines, new methods are constantly implemented at all levels of strength and conditioning. In recent years, one of these that has gained widespread acceptance in training programs throughout the world is the combination of elastic bands added to free-weight exercises (3,9,11,16,17,20). Despite common use and anecdotal support, controlled prospective research has been slow to investigate the claim that this form of variable resistance exercise is an effective training technique for improving muscular strength and explosive power. Only recently have findings begun to surface that support these practices (1,5,10,12,15).

Arising from the sport of competitive powerlifting (16,17), the addition of elastic bands to a traditional form of free-weight resistance exercise is suggested to effectively alter the kinetics of multijoint exercises such as the squat (14,19). Although some evidence does not support this hypothesis (6), the work of Wallace et al. (19) has demonstrated that, if used with maximal voluntary effort (4,21), elastic bands allow for higher forces and power outputs than free weights alone during single bouts of squats. This evidence lends support to the hypothesis that adding elastic bands to free weights during multijoint exercise allows the lifter to encounter greater peak torque and peak power during training and, thus, provide a greater and more specific training stimulus to explosive athletic activities.

If the addition of elastic bands to free-weight exercise does alter the kinetics and improve the resulting training effects of multijoint activities, then it becomes necessary to investigate the exact loading patterns of these activities to optimally assign training program variables. Although simple in concept, this directive poses 3 specific areas of concern: 1) the thickness of the elastic band, 2) the attachment technique used, and 3) the type of exercise being performed. Therefore, the purpose of this study was to determine the length vs. tension properties of multiple sizes of a set of commonly used, commercially available elastic bands to accurately quantify the resistance applied to free weight plus elastic resistance band squats (SQ) and bench press (BP).

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Methods

Experimental Approach to the Problem

This study was undertaken to examine the exact loading patterns of elastic bands commonly used in resistance training programs for strength and power development. Because the method of band attachment differs between the BP and SQ, it also determines the total thickness of elastic (resulting number of band lengths) acting on the bar (see Figures 2-5). Two sets of testing conditions were, therefore, performed during a 1-day session in the on-campus recreational facility.

Figure 2

Figure 2

Figure 3

Figure 3

Figure 4

Figure 4

Figure 5

Figure 5

A major outcome of this study is the creation of prediction equations for SQ and BP so that precise training loads can be easily identified. For example, for exercise load prescription at a later time, it would only be necessary to measure the length of excursion for a given lifter (x) before inputting this value into these equations to yield the amount of resistance (y) that a given band would provide that lifter for that exercise. It is, therefore, necessary to express our length measurements as the independent variable and the resistance provided by the band as the dependent variable to create useful predictions.

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Procedures

Five elastic bands (Flex Bands, eliteFTS; London, Ohio) of varying thickness (orange, red, black, purple, and green, listed in increasing order of thickness) were brought to the facility, and each was, in turn, affixed to the cross-beam of a squat rack. A tape measure was attached to the cross-beam with the baseline assigned to the furthest point of the fixed band end with the free end hanging down toward the ground. After resting length assessment, a single dumbbell was added to the band and balanced independent from human contact along a horizontal plane. The newly attained length was measured to the opposite side of the midpoint of the center of each dumbbell (Figure 1). This end-to-end assessment of band length was consistent for all bands and all trials. Load and the deformation resulting from dumbbells of progressively increasing size were recorded to the nearest 0.5 cm. This process was repeated until the band length exceeded any length of practical significance (>200 cm). This end point is justified by the finding that no participants demonstrated band lengths >180 cm in a separate training study involving participants of average height with this methodology.

Figure 1

Figure 1

As stated previously, this testing process was performed twice to account for the differing attachment conditions. First, attachments as seen with SQ result in a knotted or “choked” configuration (Figure 2). This attachment method creates a situation with one free end working to create the knot and the other end acting on the dumbbell. This results in only 2 lengths of band contributing to the load per band (Figure 3). With the BP configuration, the band was wrapped over the cross-beam (Figure 4) such that both free ends were acting on the dumbbell. This produces a condition resulting in 4 lengths of elastic per band (Figure 5) that would contribute to the load during this exercise.

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Statistical Analyses

All data were plotted as length vs. load curves, and nonlinear logarithmic regression lines were fit to each banding condition, for which coefficients of determination (R2) for regressions of all banding conditions were then created.

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Results

The original data for the BP band attachment and resulting regression lines for all 5 bands are shown in Figure 6. For all band conditions, the R2 values exceeded 0.9882. The bands, in order of increasing tension at any given length, were as follows: orange, red, black, purple, and green.

Figure 6

Figure 6

The original data for the SQ band attachment and resulting regression lines for all 5 bands are shown in Figure 7. With the exception of the thinnest band (orange) that demonstrated an R2 = 0.9623, all band conditions exceeded an R2 = 0.9863. The bands, in order of increasing tension at any given length, were as follows: orange, red, black, purple, and green.

Figure 7

Figure 7

The prediction equations and R2 values for all bands and loading conditions are shown in Table 1.

Table 1

Table 1

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Discussion

This study demonstrates that a number of factors influence the load that is applied to free-weight exercises when elastic resistance is added. This study quantifies the large differences in the applied load that occur as a result of the thickness of the elastic band, the type of exercise being performed, and, thus, the attachment technique used. These factors are further complicated by the varying anthropometrics of different lifters and the likely variance in elastic properties resulting from the multiple manufacturers of elastic bands. The overall combination of these factors is likely to lead to a great deal of error in loading prescription unless each of these factors is, in turn, accounted for.

In both attachment conditions, marked differences were demonstrated between bands. This became more discrepant at greater lengths and was particularly notable because the assessed band lengths that would be used during combined free-weight and elastic exercise would occur after the steep phases of the curves. As part of another ongoing training study of novice, male and female collegiate lifters of average size, the assessed band lengths would be greater than 155 cm for the BP conditions and greater than 140 cm for the SQ conditions (unpublished data). As an example, a participant with a BP band reach of 155 cm would encounter a range of 26-261 kg from the thinnest to the thickest band. The same participant, with a SQ reach of 140 cm, would encounter a range of 24-117 kg. Obviously, this large range of load would greatly affect the volume and intensity of a program using these techniques. With previous work supporting the idea that only proportionately lighter band contributions might be effective in increasing strength and power variables (5,6), the regression equations from this study are, therefore, critical in determining the proper integration of band and free weight to be used during training sessions. This level of integration, though as yet not clearly defined, is important because, as Wallace et al. (19) have suggested, there exists a “ceiling for the amount of resistance that can come from bands before a decline in performance measures is observed.”

A second major finding of this study is that the manner in which the elastic band is affixed can drastically influence the loading that would ensue. Dozens of equipment manufacturers produce slightly different designs of equipment such as squat racks and benches. The manner in which a trainer attaches bands to his or her varied equipment is likely to be highly variable from facility to facility. We have demonstrated that large differences are found between attachment configurations such that a single black band at the same length can differ by as much as 13 kg at the practically relevant length of 140 cm. It is, therefore, likely that band-loading quantification either should be performed in accordance with facility-specific concerns or the strength and conditioning profession should work toward adopting a universal means of attachment.

Our third finding is that both BP and SQ attachment configurations reveal exceptionally high R2 values when fitted with nonlinear logarithmic lines of regression. This might be in contrast to previous published work describing the application of elastic plus free weight as being of a strictly linear nature (9,18,19). This finding is particularly important when taking into account one of the mechanical theories of elastic band training. Because common extension exercises such as SQ and BP, when performed to maximal effort velocity, include a deceleration phase during the latter portions of the range of motion (7,8,13), adding elastic band resistance therefore allows for a variable resistance pattern that might better match explosive mechanics. This is theorized to occur because elastic effectively adds resistance to the area of naturally occurring deceleration such that the lifter might be allowed to continue to exert maximally until lockout is achieved (2,3,19). Said another way, instead of the lifter exhibiting nervous system inhibition to decelerate the bar, he or she actually continues to maximally recruit motor units until lockout is completed; the deceleration therefore results from increased mechanical load, not a diminishing nervous stimulus. Although these exercises previously were assumed to be linear in nature, this study provides evidence to the contrary and proposes high rates of force development during the middle phases of the range of motion giving way to a decreasing rate of loading in the later phases of a multijoint extension exercise. It is further suggested that a more complete kinetic and kinematic analysis of the major elastic band plus free-weight exercises be completed to further classify the loading effects of this training technique.

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Practical Applications

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 be ascertained that a person with a BP reach of 175 cm (x) will incur a black band load of 38 kg (y) at the conclusion of the concentric phase (using the equation: y = 29.064 Ln(x) − 111.860). For SQ, the black band resistance for a 145-cm band length (x) will be 10.5 kg (y), but this must be multiplied by 2 to account for each of the 2 bands on either end of the barbell during this type of exercise so that the total weight addition will be 21 kg at the conclusion of the concentric phase (using the equation: y = 17.078 Ln(x) − 74.643). Large differences in the applied load exist as a result of 1) the thickness of the elastic band, 2) the attachment technique used, 3) the type of exercise being performed, 4) the individual anthropometrics of the individual lifter, and 5) likely, the manufacturer of the elastic band.

Because of these multiple factors at present, caution is advised when acquiring, researching, and implementing elastic band and free-weight exercises. Until further consensus is developed to more consistently identify the exact loads that are incurred during training with these methods, it is recommended that each facility (or trainer) adopt its own form of quantification to match its own unique set of circumstances.

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Acknowledgments

The bands used in this study were purchased online through eliteFTS, and the authors maintain no professional affiliation with this company at the time of this submission. The results of the present study do not constitute endorsement of the products of eliteFTS by the authors, Loyola Marymount University, or the NSCA.

We would graciously like to thank Recreation Services at Loyola Marymount and Dana McCaw along with every single member of the I.N.V.E.S.T. (Investigating New Variables in Exercise and Strength Training) research team, including Adam Afflalo, Will Alvarenga, Noel Barragan, Ashley Boyer, Bryce Brown, Jackie Canepa, Alex Cedillo, Reese Cuddy, Erica Hanson, Phil Higgins, Crystal Holley, Emileigh Ip, David Kohler, Brooke Lejeune-Chanman, Landon Storaasli, Jen Topor, Sammy Torres, and Sean Travis.

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References

1. Anderson, CE, Sforzo, GA, and Sigg, JA. Combining elastic tension with free weight resistance training [Abstract]. Med Sci Sports Exerc 37: S186, 2005.
2. Anderson, CE, Sforzo, GA, and Sigg, JA. The effects of combining elastic and free weight resistance on strength and power in athletes. J Strength Cond Res 22: 567-574, 2008.
3. Baker, D and Newton, RU. Methods to increase the effectiveness of maximal power training for the upper body. Strength Cond J 27: 24-32, 2005.
4. Behm, DG and Sale, DG. Intended rather than actual movement velocity determines velocity-specific training response. J Appl Physiol 74: 359-368, 1993.
5. Cronin, J, McNair, PJ, and Marshall, RN. The effects of bungy weight training on muscle function and functional performance. J Sports Sci 21: 59-71, 2003.
6. Ebben, WP and Jensen, RL. Electromyographic and kinetic analysis of traditional, chain, and elastic band squats. J Strength Cond Res 16: 547-550, 2002.
7. Elliott, BC, Wilson, GJ, and Kerr, GK. A biomechanical analysis of the sticking region in the bench press. Med Sci Sports Exerc 21: 450-462, 1989.
8. Escamilla, RF, Fleisig, GS, Lowry, TM, Barrentine, SW, and Andrews, JR. A three-dimensional biomechanical analysis of the squat during varying stance widths. Med Sci Sports Exerc 33: 984-998, 2001.
9. Findley, BW. Point/counterpoint: training with rubber bands. Strength Cond J 26(6): 68-69, 2004.
10. Ghigiarelli, J, Nagle, FG, Irrgang, J, Robertson, R, and Msylinksi, T. The effects of a seven-week heavy elastic band weighted chain program on maximum upper body strength and upper body power in a sample of division 1-AA football players [Abstract]. J Strength Cond Res 21: e11, 2007.
11. Heinecke, M, Jovick, B, Cooper, Z, and Wiechert, J. Comparison of strength gains in variable resistance bench press and isotonic bench press [Abstract]. J Strength Cond Res 18: 10, 2004.
12. Jakubiak, N and Saunders, DH. The feasibility and efficacy of elastic resistance training for improving the velocity of the Olympic Taekwondo turning kick. J Strength Cond Res 22: 1194-1197, 2008.
13. Madsen, N and McLaughlin, T. Kinematic factors influencing performance and injury risk in the bench press exercise. Med Sci Sports Exerc 16: 376-381, 1984.
14. Newton, RU, Robertson, M, Dugan, E, Hasson, C, Cecil, J, Gerber, A, Hill, J, and Schwier, L. Heavy elastic bands alter force, velocity, and power output during back squat lifts [Abstract]. J Strength Cond Res 16: 1-18, 2002.
15. Rhea, MR, Kenn, J, and Peterson, M. The use of accommodating resistance for the development of lower body power among college athletes [Abstract]. J Strength Cond Res 21: e25, 2007.
16. Simmons, LP. Chain reactions: accommodating leverages. Powerlifting USA 19: 2-3, 1996.
17. Simmons, LP. Bands and chains. Powerlifting USA 22: 26-27, 1999.
18. Simoneau, GG, Bereda, SM, Sobush, DC, and Starsky, AJ. Biomechanics of elastic resistance in therapeutic exercise programs. J Orthop Sports Phys Ther 31: 16-24, 2001.
19. Wallace, BJ, Winchester, JB, and McGuigan, MR. Effects of elastic bands on force and power characteristics during the back squat exercise. J Strength Cond Res 20: 268-272, 2006.
20. Warpeha, JM. Accommodating resistance. NSCA Perform Train J 4: 22-23, 2002.
21. Young, WB and Bilby, GE. The effect of voluntary effort to influence speed of contraction on strength, muscular power, and hypertrophy development. J Strength Cond Res 7: 172-178, 1993.
Keywords:

load; variable resistance; volume

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