Strength training involving modalities that use elastic bands (EBs) and weighted chains (WCs) has received widespread recognition and increased popularity within recent years (2,13,15,24,26,29,31,35,38,43). Considered a form of nontraditional training, the external resistance using these methods may be altered to target specific neuromuscular traits and change the transfer specificity of a given training program (23,27). Changing these resistance training modalities, an attempt has been made to specifically match the strength curve of a particular exercise movement (18,45). Few studies have explored the effects of these types of variable resistance training (VRT) using dynamic free-weight exercises on increases in strength, speed, and power.
When hanging chains are added to the ends of a barbell, free-weight exercise models characteristics that are similar to VRT. The functions of VRT using free-weight exercises are twofold: (a) Load will increase where the muscle joint has more leverage, such as in the early phases of a lift and (b) decreasing loads will follow where the muscle joint has little leverage, such as in the later phases of a lift (i.e., the deep squat position). It is hypothesized that VRT may be a beneficial modality of strength training based on the theoretical concept of the muscle-joint relationship. As an example, a WC system will accommodate a load at weaker joint angles. Practitioners have also reported additional benefits from WCs oscillating and swinging throughout a range of motion that include the increased use of stabilizer muscles (7,35).
Previously, EBs have been used primarily in rehabilitation settings (36,37) for exclusive sport-specific objectives, such as improving strength and power in racquet sports (6). Recently, EBs have been applied to both structural and power movements in an effort to induce greater strength gains (2,13,29,35,38). Because of the tendency of the EBs to pull a barbell down during early phases of a lift, an increased eccentric loading phase occurs, which supports higher eccentric velocities associated with this type of training. Furthermore, evidence supports eccentric training as a greater stimulus to enhance metabolic efficiency and generate higher forces than concentric contraction (3,8,14,21).
Modifying bands to a strength training apparatus in such a way that the return velocity and force required to decelerate the load (at the end of the eccentric phase) has reported promising results (2,13,29,38) and warrants further investigation. At present, the effects of VRT remain unclear. In addition, most investigations using bands have been acute in duration, and evidence is lacking that examines the benefits of WCs using a longitudinal training study design. In the present study, it was hypothesized that peak power (PP) and maximum bench press (BP) would increase using VRT compared with traditional resistance exercise after a 7-week offseason conditioning program. Therefore, the purpose of this investigation was to explore the effects of heavy EBs and WCs on upper-body maximum strength and power using a sample of Division 1AA football players.
Experimental Approach to the Problem
This study investigated the effects of EB training (Iron Woody Fitness, Olney, Mont.) and WC training (Westside Barbell, Columbus, Ohio) as a part of a 7-week offseason conditioning program. Preseason and postseason data were collected, and mean PP, peak velocity (PV), and 5-7 repetition maximum (RM) were compared.
Baseline testing consisted of measuring maximum upper-body strength and power in the BP exercise. Before testing, a blocking variable of BP per body weight (BW) was used to acquire the selection of subjects from the entire football roster to increase the homogeneity and effect size of the sample. After initial screening, the highest 36 BP scores from the winter testing sessions qualified. Subjects were randomly assigned into 1 of 3 groups consisting of EB, WC, or the control group. Each group followed the same prescribed 7-week strength and conditioning program. Muscular strength and power testing was conducted at pre (week 0), post (week 7), and post 2 (week 8) time points.
Thirty-six Division 1AA football players from Robert Morris University participated in this investigation. Table 1 shows the descriptive data for the subjects. Approval of Robert Morris head football coach and head strength and conditioning coach was obtained before the start of the study. All participants were informed and provided consent according to the University of Pittsburgh Institutional Review Board approved protocol.
The primary objective of the offseason strength program was to increase strength and power in both the lower and upper body. The resistance training program required a total of 4-5 resistance training sessions per week across a 7-week period for a program total of 28 sessions. These sessions used a split routine format (Table 2) allowing 48 hours recovery before the same body part was trained for a second time that week. All subjects performed lower-body exercises on Mondays and Thursdays and upper-body exercises on Tuesdays and Fridays. Exercise order typically progressed from major muscle groups to smaller muscle groups within each session. Subjects typically performed 7-8 exercises at a given session, with a primary focus on dynamic free-weight exercises.
An undulating periodized design (31) on nontreatment days consisted of heavy loading sessions at 4-6 repetitions in the early part of the week followed by the light loading of 2-4 repetitions (power) sessions in the later part of the week. All major muscle groups performed upper-body exercises that incorporated dynamic BP, dumbbell BP, floor press, and various supplemental arm exercises. Lower-body exercises typically consisted of dynamic squat, box squat, one legged lunges, glute ham raises, hip extension and flexion, and leg curls. This dose and type of intervention have typically been recommended to elicit strength and power adaptations for advanced athletes (22,30).
During treatment days, which consisted of the second upper-body day of the week (Friday), the experimental groups attached the EB or WC to the BP apparatus during their speed BP sets. All 3 groups performed 6 sets of 3 repetitions and were instructed to accelerate the barbell as fast as possible. A qualified strength and conditioning coach closely supervised and tracked training loads and volumes to ensure high-intensity levels, proper technique, motivation, and adherence to the program. Each subject recorded all training sessions, loading (kilograms), and number of repetitions per set in a training log. The program took place 1 week after winter break had ended during the 2006 calendar year (January 16 to March 17), with 1 week of spring break during the second week of March.
Primary Testing Procedures
Subjects reported for pretesting during week 1, where the multiple 5-7RM BP and 5RM speed BP tests were conducted on separate days. Weeks 2-8 consisted of the training intervention (Table 2). Subjects reported for follow-up testing during week 9.
Five to Seven Repetition Predicted Maximum Bench Press
Multiple RM prediction models are considered valid (r = 0.84-0.92), safe, and reliable methods to predict 1RM maximum testing (9,17,39,42). During week 1, subjects performed a multiple 5-7RM BP test (to failure) using a prediction chart to predict their 1RM. Based on the number of repetitions completed and the particular load (weight on the barbell) used, the subject's predicted 1RM BP was calculated.
Subjects followed a warm-up (1) and testing protocol reported by Ware (39). Bench press repetitions followed the standard “touch and go” protocol. The bar was required to touch the chest before pressing to full arms extension. Subjects placed hands slightly wider than shoulder width grip on the barbell, and feet were placed on the ground during all sets. Subjects performed a warm-up lift of 5-10 repetitions at 40-60% perceived maximum exertion. After a 1-minute rest with light stretching, subjects completed 3-5 repetitions at 60-80% of perceived maximum exertion. After a 3- to 5-minute rest, a weight that was approximately 85% of their probable 1RM was loaded on to barbell. Using the selected weight, subjects performed as many repetitions to failure as possible. The final number of valid repetitions was recorded. Based on the number of repetitions performed, a prediction equation was used (1RM = [0.033 rep wt] × repetitions + rep wt) (16).
Five Repetition Maximum Speed Bench Press Test
The 5RM speed BP was used to determine and evaluate upper-body muscular power for each subject. In each of these sessions, subjects were instructed to accelerate the barbell as fast as possible during the entire range of motion for a total of 5 repetitions (5,25). The 5RM speed BP testing was performed 3 days after the predicted 1RM prediction test. After the warm-up, subjects used 50% of the load from their predicted 1RM test and placed it on the bar. Subjects were instructed to lower the barbell as fast and controlled as possible (approximately 1-second tempo during lowering followed by maximal acceleration during raising) while maintaining proper form. After the barbell touched the chest, subjects were instructed to accelerate the barbell upwards as fast as possible until arms reached full extension. Subjects performed 2 sets of 5 repetitions using this technique. Average and PV (meters per second) and average and PP values (Watts) were recorded across both sets using the Fitrodyne device (Fitrodyne, Bratislava, Slovak Republic). The highest mean value from both sets was used for analysis.
Second Post-Testing Session for Five Repetition Maximum Speed Bench Press
Subjects were post-tested in the speed BP test on two separate occasions. The first day consisted of testing each subject at 50% of their original pretest predicted 1RM. The second day consisted of testing each subject at 50% of their new predicted 1RM, which was calculated from the post-1RM predicted test. According to the literature, optimal loading for power output in this particular exercise (nonballistic) is approximately 50-55% of subjects 1RM (4,33). Because of strength gains from the training intervention, subjects were tested at their post-test 1RM so optimal load would ensure the highest power output.
Three chains (Westside Barbell, Columbus, Ohio) were attached to each side of a barbell, for a total of 6 chains on the bar. Four chains consisted of training chains (2 on each side), and 2 were considered support chains (1 on each side). A training chain was 5 ft long and weighed 20 lb. Each 5-ft support chain weighed 4 lb. The combined weight of all chains used was approximately 85-90 lb. The 2 support chains used attached the training chains to the barbell and were lowered to the ground during work sets.
Elastic bands (Iron Woody Fitness) progressively increase overall resistance during the concentric portion of each repetition. Conversely, during the eccentric portion of each repetition, resistance progressively decreased. The EBs were anchored at the bottom of the BP apparatus, creating maximum tension at the top of the lift with lowest tension at the bottom.
The Fitrodyne The lineatheweightlifting analyzer (11,20) consisted of 2 components: a velocity sensor unit and a microcomputer. The velocity sensor unit is connected to the weight by a Kevlar cable with strap and Velcro. Using mass submitted input before exercise, the system calculated the following dependent variables: average velocity (meters per second), PV (meters per second), average power (Watts), and PP (Watts) for each repetition in the concentric phase of the exercise.
Data analyses were performed using SPSS version 14.0 for windows statistical software (SPSS, Inc., Chicago, Ill.). Descriptive data for subject characteristics and experimental variables were calculated as mean and SD. A repeated-measures 2-way analysis of variance (ANOVA) was computed to examine differences in maximal strength and maximal power measurements across 2 testing sessions between the experimental and control groups. Statistical significance was set at α ≤ 0.05. In addition, an intraclass correlation coefficient (ICC) was used to examine the reliability of the Fitrodyne unit on testing session days. In addition, a one-way ANOVA was conducted on pretest 1RM (p ≤ 0.24) BP and pretest 5RM speed BP (p ≤ 0.56) to assure there was not a significant difference between the groups before treatment was administered.
One Repetition Maximum Predicted Maximum Bench Press
Strength and power data are presented for each of the training groups as a result of the 7-week intervention (Table 3). The 1RM predicted maximum strength test increased significantly (p < 0.05) from week 1 to 8 across all groups with no significant differences between the groups. The WC, EB, and control groups significantly increased (p = 0.00) their predicted 1RM maximum BP by 9.6 (7), 10 (8), and 7.7 kg (5%), respectively (Figure 1).
Five Repetition Maximum Bench Press
No significant differences for between- or within-group effects was observed from the 5RM speed BP test (Figure 2). However, further analysis of these data indicated a trend towards significance in both the WC and EB groups when the highest recorded power value per repetition (Figure 3) from the 5RM set was selected (p < 0.11). Although not significant, the band condition increased their highest repetition value from an average of 848 to 883 W. The chain group increased from 856 to 878 W, and the control group decreased from 928 to 918 W. The EB group also recorded the highest relative to BW power increase from 4.24 to 4.43, where the WC group increased from 4.13 to 4.26, and the control group decreased from 4.05 to 4.02.
Figure 4 represents the change in PV values across all groups for the 3 testing sessions. On the second post-testing session, subjects performed the 5RM speed BP at their new 1RMs recorded from the post-test 1RM sessions. Results indicated a significant effect (p < 0.05) for decreasing velocity between post-testing session 1 and post-testing session 2.
The PP measurement in the BP exercise using the Fitrodyne device had an average Cronbach's ICC of R = 0.981. ICC was 0.988, 0.981, and 0.984 for the pretest, post-test 1, and post-test 2 sessions, respectively. Figure 5 represents the range of the average PP values for each subject over 3 trials. For each column, 3 intrareliability correlations were calculated for each trial for each subject and then averaged together. The 35 ICCs were averaged to produce an overall ICC (r = 0.98).
From this study, we observed a significant increase in maximum strength and a nonsignificant increase in PP in the VRT compared with the traditional free-weight training group. Whereas the prevalence of WC training and EB training interventions has increased, evidence has shown equivocal results (2,5,7,15,24,26,38). However, studies using a long-term training program in conjunction with these untraditional styles are promising (2,10,13,26,31,43).
The effectiveness of EB training remains unclear; however, recent studies have shown gains in muscular power and maximal force production (10,13,29,38). Elastic band training is reported to provide greater PP and peak force with resulting increases in velocity of eccentric muscle contraction caused by the downward pull of the bands on the barbell during the eccentric loading phase (2,13,38). Eccentric loading is a viable stimulus when training for strength and power because of the series elastic component of the skeletal muscle tendon and its ability to store elastic energy (8,13). By attaching the EBs in such a way in which maximum force is achieved at full arms extension, greater eccentric velocities are observed during the initial phase of eccentric contraction (13,38). In addition, a greater force is required to slow the barbell down during the later stages of eccentric contraction because of the large prestretch at the onset of the movement (13,38). It is hypothesized that long-term training adaptations from this type of eccentric loading will alter the behavior of human skeletal muscle in an attempt to increase strength and power.
Weighted chains alter the kinetics of the barbell during the entire range of movement as well as increasing the mechanical advantage of the movement (5,7,35). This system accommodates a lifter by decreasing load at the weakest joint position and increasing the load at the lifter's strongest joint position. It is hypothesized that WC training would provide optimal resistance throughout the entire range of motion through the accommodation of the changing length-tension relationship of the musculoskeletal system (5,15,35,45). Matching the load with the strength curve of the exercise movement is known as transfer specificity or transference (7). The principle of transfer specificity is defined as performing movement patterns most similar to the movements of the respected sport to maximize on field performance (7,23,41). In this case, WC training would theoretically match movements such as the jumping and chest press exercises.
Weighted chain training has also been reported as a method for injury prevention because decreased loads occur at the deep squat position, where shear forces on the knee are greatest (24). In addition, because of the progressive decrease in resistance at the end of the eccentric phase, a strength trainer will spend a longer period of time in the acceleration phase at the early stages of the concentric contraction because of lighter loads at this time frame. Furthermore, accommodating resistance techniques are purported to be more advantageous than traditional strength training because of decreased time in the deceleration phase that accompanies traditional free-weight training. Training methods that shorten the deceleration phase and increase the time the barbell is in PV may increase one's rate of force development over time (44).
From the present study, it was unclear as to whether increases in maximum strength and nonsignificant power output were specifically caused by the treatment (training program with bands and chains) or to the general conditioning adaptation that would typically occur in an offseason training program. All subjects underwent an advanced training program, which consisted of training 4-5 days per week and performing multi-joint exercises loaded at 85% 1RM for strength gains and 50% 1RM for muscular power enhancement. It is well documented that this type of intervention is recommended to elicit these particular performance gains similar to a dose-response relationship in advanced athletes (22,30). Although no significance occurred between the groups, the WC and EB groups seemed to respond better to the treatment when comparing 1RM BP scores to the control group (EB , WC , and control [5%]). This supports recent evidence that EB training increases maximal force production (2,38).
Whereas this study was shorter in duration (7 weeks) compared with other training interventions (11-16 weeks) previously reported, it was of sufficient time to observe strength and power gains (4-6 weeks) (22). Subjects trained with EBs and WCs 1 session per week for 7 weeks for a total of 7 sessions. The current strength coach for Robert Morris University assumed a conservative approach by keeping the frequency of type of training minimal to 1 day per week. Other training studies have prescribed the duration of training of 3 days to as long as 10 weeks, with the frequency of training being 1-2 days per week (2,13,15,32,38). Therefore, it is likely that the total time under treatment may have not been sufficient.
Although no significance was found in the 5RM PP test using the average of 5 repetitions, the results indicated greater improvements in the EB and WC groups compared with control when the 2 highest and single highest PP repetitions were selected. Because subjects produced their highest values earlier in the performance set, investigators filtered the data by selecting the top (repetitions 1 and 2) power values. Evidence supports the highest motor unit efficiency occurs at low fatigue levels that correspond to the first few repetitions of a set (18,45).
Increases in power values for repetitions 1 and 2 in the experimental groups may have reflected increases in reversible strength, defined as “the ability to accelerate a force in the opposite direction in a stretch shortening cyclic action” (34,45). In the present investigation, subjects were instructed to perform the traditional BP exercise “explosively,” which required acceleration of the barbell as quick as possible from eccentric to subsequent concentric contraction. Because of decreasing loads removed from the bar at the end of the eccentric phase during the EB and WC exercises, experimental groups were able to accelerate the barbell faster throughout the concentric portion of the lift resulting in higher PP values. It has also been suggested that EB training allows a lifter to be in longer state of acceleration during the concentric phase because of increasing force towards starting position (10).
Another possible explanation for the lack of significance in overall PP measures is exercise selection. One of the limitations of traditional BP is the large deceleration period at the end of the concentric phase (16,28). Research suggests that ballistic training is used to compensate for this (23,28). Ballistic training occurs when the lifter attempts to accelerate the barbell throughout an unlimited range of motion, which typically results in either a jumping motion or the release of the barbell from the hands (34). This type of training has been shown to induce greater power outputs compared with traditional strength training (nonballistic) (19,25). Subjects in the present investigation were instructed to accelerate the barbell throughout the range of motion; however, they were not allowed to release the barbell at the end of concentric movement, therefore performing a more traditional bench exercise. Access to a Smith machine or machine type apparatus, which would have allowed ballistic training to be performed, was not available.
It is suggested that because of the increases in predicted 1RM pre- to post-test, subjects completing post-test 1 for the speed BP were using too light of a load. This was apparent from both the observed deterioration of form and technique (i.e., back coming off bench), as well as low PP scores. The post-testing 1 load was based on the subject's pretest predicted 1RM BP at the start of the training program. From the increase in the predicted 1RM values, subjects were loaded at approximately 40-45% of their predicted 1RM. During second post-testing session, using 50% of the predicted 1RM post-test scores, subjects were loaded with approximately 50-55% of their predicted 1RM, which deemed a more optimal weight for PP as observed with the PP values. It is reported that in well-trained athletes, proper loading for upper-body power in the BP exercise is recommended at 50-55% (4), and this was supported in the present findings.
The Fitrodyne has been commercially available and reliable measurement in published research (11,20,41). Similar to previous studies, the average test-retest reliability coefficients in this investigation was r = 0.98. From these conclusions, it can be suggested that while costly, the Fitroydne is a feasible and reliable measurement for power output. Recently, this device has been validated in which the findings were less desirable (12,41). A limitation of this device was the manner in which force and power output were calculated. It has been documented that using a one linear position transducer device + mass method significantly underestimates power output because it does not account for the acceleration of the mass on the barbell (12). Other systems of measurement such as using two linear position transducers + force plate method may improve the validity of the results.
The results of this study suggest that the use of accommodating resistance techniques of heavy EBs or hanging WCs to a barbell may increase maximum strength development and increase power output. In addition, results indicate that the optimal loading when using these modalities should be approximately 40-50% of the lifters 1RM in the BP exercise. Because of the limitations of the traditional BP exercise, including greater deceleration phase and lower eccentric velocities, VRT training allows the lifter to achieve greater velocity of contraction during the initial stages of the eccentric and concentric phases. This is caused by the altered barbell kinetics from the deloading and reloading of chain weight and elastic tension on the barbell throughout the exercise movement.
These results suggest that when WCs and EBs are incorporated into offseason and in-season training cycles, athletes are provided with a unique yet viable method of increasing strength and power variables. These methods are particularly useful in exercises that mimic ballistic movements, such as the BP or squat exercise performed explosively. Variable resistant training techniques also allow the strength practitioner additional flexibility in exercise prescription and exercise selection. An alteration from traditional exercises of this nature may enhance athlete compliance, motivation, and interest to conditioning workouts.
Based on the findings in this study, it seems programs short in duration using these training techniques (approximately 7 weeks) may not be a sufficient stimulus to see a training adaptation, especially in a trained sample population. It is recommended that additional studies measuring peak force and PP should explore the longitudinal training effects of variable resistance training. It is understood that both systems alter force, muscle activity, barbell velocity, and acceleration at different spectrums of eccentric and concentric contraction. However, it remains unclear if chronic training longer than 10-12 weeks from these methods would be beneficial to the athlete and their sport-specific performance.
This study was funded by the University of Pittsburgh School of Education graduate research grant. The primary investigator would like to thank Tom Myslinski, MS, CSCS, head strength coach for the Cleveland Browns for his contributions and assistance, which made this study possible.
1. American College of Sports Medicine (6th ed.). Acsm's Guidelines for Exercise Testing and Prescription
. Philadelphia, PA: Lippincott Williams & Wilkins, 2000.
2. Andersen, C. Effects of combined elastic-free weight resistance (Abstract). Med Sci Sports Exerc
37: S186, 2005.
3. Asmussen, E and Bonde-Petersen, F. Apparent efficiency and storage of elastic energy in human skeletal muscles during exercise. Acta Physiol Scand
92: 537-545, 1974.
4. Baker, D, Nance, S, and Moore, M. The Load that maximizes the average mechanical power output during explosive bench press throws in highly trained athletes. J Strength Cond Res
15: 20-24, 2001.
5. 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.
6. Behm, DG. Strength and power conditioning for racquet sports. Natl Strength Cond Assoc J
10: 66-70, 1998.
7. Berning, J, Coker, C, and Adams, K. Using chains for strength and conditioning. Natl Strength Cond Assoc J
26: 80-84, 2004.
8. Bobbert, KG, Gerritsen, MC, Litjens, A, and Van Soenst, AJ. Drop jumping I. The influence of jumping technique on the biomechanics of jumping. Med Sci Sports Exerc
19: 332-339, 1987.
9. Chapman, PP, Whitehead, JR, and Binkert, RH. The 225-lb reps-to-fatigue as a submaximal estimate of 1-Rm bench press performance in college football players. J Strength Cond Res
12: 258-261, 1998.
10. Claxton, J. Kinematics of explosive upper body movements: a comparison of the traditional bench press, bench press throw, and bungy resisted bench press. Master's thesis, Auckland Institute of Technology, 2005.
11. Coelho, CW, Hamar, D, and Araujo, CGSD. Physiological responses using two high speed resistance training protocols. J Strength Cond Res
17: 334-337, 2003.
12. Cormie, P, Mcbride, J, and Mccaulley, GO. Validity in power measurement techniques in dynamic lower body resistance exercise. J Appl Biomech
23: 103-118, 2007.
13. 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.
14. Doan, BK, Newton, RU, Marsit, JL, Triplett-Mcbride, T, Koziris, LP, Fry, A, and Kraemer, WJ. Effects of increased eccentric loading on bench press 1rm. J Strength Cond Res
16: 9-13, 2002.
15. Ebben, WP and Jensen, RL. Electromyographic and kinetic analysis of traditional, chain, and elastic band squats. J Strength Cond Res
16: 547-550, 2002.
16. Elliot, BC, Wilson, GJ, and Kerr, GJ. A biomechanical analysis of the sticking region in the bench press. Med Sci Sports Exerc
21: 450-462, 1989.
17. Epley, B. Poundage Chart
. Lincoln, NE: Boyd Epley Workout, 1985.
18. Fleck, SJ and Kraemer, WJ. Designing Resistance Training Programs (3rd ed.). Champaign, IL: Human Kinetics, 2004.
19. Haff, G, Whitley, A, and Potteiger, JA. A brief review: explosive exercises and sports performance. Strength Cond J
23: 13-20, 2001.
20. Jennings, C, Viljoen, W, Durandt, J, and Lambert, M. The reliability of the Fitrodyne as a measure of muscle power. J Strength Cond Res
19: 859-863, 2005.
21. Kaneko, M, Fuchimoto, T, Toji, H, and Suei, K. Training effect of different loads on the force-velocity relationship and mechanical power output in human muscle. Scand J Sports Sci
5: 50-55, 1983.
22. Kraemer, WJ, Adama, K, Cafarelli, E, Dudley, GA, Dooly, C, Feigenbaum, MS, Fleck, SJ, Franklin, B, Fry, AC, Hoffman, JR, Newton, RU, Potteiger, J, Stone, MH, Ratamess, NA, and Triplett-Mcbride, T. American College of Sports Medicine position stand. Progression models in resistance training for healthy adults. Med Sci Sports Exerc
34: 364-380, 2002.
23. Kramer, WJ. Developing a strength training workout. In: Strength Training for Sport
. Malden, MA: Blackwell Science, 2002. pp. 37-54.
24. Larson, D, Fry, A, Moore, C, Falvo, M, Smith, W, and Allerheilgen, W. The kinetic and kinematic comparisons of chains and free weights at lift specific intensities: a case study (Abstract). J Strength Cond Res
25. Mcbride, J, Triplett-Mcbride, T, Davie, A, and Newton, RU. The effect of heavy vs. light load jump squats on the development of strength, power, and speed. J Strength Cond Res
16: 75-82, 2002.
26. Mccurdy, K, Langford, G, Jenkersen, D, Ernest, J, Walters, S, and Doscher, M. Specificity of chain and plate loaded bench press training on measure of strength and power throwing velocity (Abstract). J Strength Cond Res
27. Newton, RU, Hakkinen, K, Hakkinen, A, Mccormick, M, Volek, J, and Kraemer, W J. Mixed methods resistance training increases power and strength of young and older men. Med Sci Sports Exerc
34: 1367-1375, 2002.
28. Newton, RU, Kraemer, WJ, Hakkinen, BJ, Humphries, BJ, and Murphy, AJ. Kinematics, kinetics and muscle activation during explosive upper body movements. J Appl Biomech
12: 31-43, 1996.
29. Newton, RU, Robertsen, M, Dugan, E, Hanson, C, Cecil, J, Gerber, A, Hill, J, and Schwier, L. Heavy elastic bands alter force, velocity, and power output during back squat lift (Abstract). J Strength Cond Res
30. Petersen, M, Rhea, M, and Alavar, B. Maximizing strength development in athletes: a meta-analysis to determine the dose-response relationship. J Strength Cond Res
18: 377-382, 2004.
31. Rhea, M, Ball, S, Phillps, W, and Burkett, L. A comparison of linear and daily undulating periodized programs with equated volume and intensity for strength. J Strength Cond Res
16: 250-255, 2002.
32. Rhea, M, Kenn, J, and Petersen, M. The use of accommodating resistance
for the development of lower body power among college athletes (Abstract) J Strength Cond Res
33. Sieger, JA, Gilders, RM, Staron, RS, and Hagerman, FC. Human muscle power output during upper and lower body exercises. J Strength Cond Res
16: 173-178, 2002.
34. Siff, MC. Supertraining
(6th ed.). Denver, CO: Supertraining Institute, 2003.
35. Simmons, LP. Chain reactions: accommodating leverages. Powerlifting USA
36. Simoneau, GG, Berada, SM, and Starsky, AJ. Biomechanics of elastic resistance in therapeutic exercise programs. J Occup Sports Phys Ther
31: 16-24, 2001.
37. Treiber, FA, Lott, J, Duncan, J, Slavens, G, and Davis, H. Effects of theraband and lightweight dumbbell training on shoulder rotation torque and serve performance in tennis players. Am J Sports Med
26: 510-515, 1998.
38. Wallace, B, Winchester, J, and Mcguigan, M. Effects of elastic bands on force and power characteristics during the back squat exercise. J Strength Cond Res
20: 268-272, 2006.
39. Ware, J, Clemens, C, Mayhew, J, and Johnston, T. Muscular endurance repetitions to predict bench press and squat strength in college football players. J Strength Cond Res
9: 99-103, 1995.
40. Weiss, LW, Fry, AC, Wood, LE, Relyea, GE, Melton, C. Comparative effects of deep versus shallow squat and leg press training on vertical jumping ability and related factors. J Strength Cond Res
14: 241-247, 2000.
41. Weiss, L, Schilling, B, Flavo, M, Liggins, R, Lohnes, C, Barnes, J, and Creasy, A. Reliability and precision of power measures obtained via simple dynamometry during bench press throws (Abstract). J Strength Cond Res
42. Whisenant, M, Panton, L, East, W, and Broeder, C. Validation of submaximal prediction equations on the 1 repetition maximum bench press test on a group of collegiate football players. J Strength Cond Res
17: 221-227, 2003.
43. Winters, J. The effects of the application of elastic resistance to a free weight bench press on upper body strength and power output production (Abstract). J Strength Cond Res
44. Young, W and Bibly, 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.
45. Zatsiorsky, VM. Science and Practice of Strength Training
. Champaign, IL: Human Kinetics, 1995.
Keywords:© 2009 National Strength and Conditioning Association
accommodating resistance; eccentric training; peak velocity.