Applications now being accepted for Board of Directors and committee openings.
My Account Preferences
My Contact Information
My Contact Preferences
Update My Password
The SCJ is the professional
journal for strength coaches, personal trainers, physical therapists, athletic
trainers, and other health professionals working in the strength and conditioning
Earn CEUs. Browse the list of NSCA approved home study courses and live events.
October 2 - 4, 2014
Join Us in D.C. Register Now and Save!
Check out the newest offering in the NSCA's Sport Performance Series.
The strength and conditioning coach’s ability to effectively manipulate the loading parameters (i.e., frequency, intensity, volume, time, resistance mode used and movement tempo) over time will inevitably determine the rate of neuromuscular adaptation and morphological growth in the athlete (1).
Variable resistance modes, such as bands and chains have been and are currently being supplemented into strength, power, and velocity training programs to elicit neuromuscular and morphological changes. The question is, are these variable resistance modes as effective as free weights alone for the development of strength, power, and speed? The simple answer is, yes.
Justifications will be based on the mechanical properties of these variable resistance modes and their relationships to the mechanical characteristics (i.e., the force-velocity capabilities) of musculoskeletal system during motion, and be supported by anecdotal claims and scientific evidence.
Material Properties of Bands and Chains
The two forms of variable resistance differ in terms of their physical and mechanical properties; rubber bands are comprised of hydrocarbon polymers, and chains are comprised of steel. Mechanically, rubber bands are viscoelastic and supply a curvilinear increase in resistance to the athlete when stretched. In contrast, chain resistance increases linearly as the links are lifted vertically (2). There are movements that may result in greater improvements from variable resistance modes based on the biomechanical structure of the musculoskeletal system.
The musculoskeletal system contains three types of strength curves (ascending, descending, and bell-shaped) with different force generating capabilities depending on the changing joint angles and the number of joints involved during the movement (see Figure 1). Single-joint movements (e.g., elbow flexion and extension, knee flexion and extension, etc.), generally have bell-shaped strength curves where maximum strength occurs around the mid-phase of the lift.
Multi-joint pulling movements (e.g., bent-over rows, pull-ups, etc.) have descending strength curves where maximum strength is produced at the beginning of the movement. Lastly, movements with ascending strength curves include variations of the squat, deadlift, and bench press as maximum strength and force capabilities occur near the top of the lift. Based on the mechanical properties of bands, chains, and the musculoskeletal system, variable resistance modes would be best suited for training ascending strength curve movements.
Figure 1. Strength Curve Classification (2)
Strength and conditioning professionals have used many different terms to describe the different resistance training phases according to the force-velocity continuum (see Figure 2). The three most popular training phase terms used by strength and conditioning professionals include maximum strength, strength-speed, and speed-strength.
Maximum strength can be defined as the maximum dynamic force the musculoskeletal system can generate to overcome the inertia of an external resistance (3,4,5). Strength-speed and speed-strength are two terms often misinterpreted due to the lack of consistency in the literature. The focus of STRENGTH-speed is on heavy load (> 90% 1RM) strength development (velocity = 0.2–0.5 m/s) and will be placed in the maximum dynamic strength section. The focus of SPEED-strength is on lower load (30 – 60% 1RM) power development (5,6). Maximal power (Pmax) training utilizes the corresponding load that produces the greatest amount of power (i.e., the optimal combination of force and velocity) during an explosive and/or ballistic movement.
Maximal power occurs around 0% 1RM (at body mass) for the explosive squat/squat jump (power = 5000–8000 W; velocity = 2.50–3.50 m/s) and between 40–60% 1RM for the bench press/bench throw (power = 700 – 1000 W; velocity = 1.20–1.50 m/s) (7,8,9,10,18). Lastly, the aim of maximal velocity training is to decrease the time it takes to move from position A to position B (i.e., moving from the bottom/base to the top/apex of a squat or bench press movement). Many practitioners believe that both supplemented band and chain resistance training can be more effective than non-supplemented training for developing maximum strength, power, and velocity in their athletes if programmed appropriately (7,8,9,11).
Figure 2. Force-Velocity Continuum (12)
Maximum Strength Training
The goal of maximum strength training is to ultimately increase the dynamic force production capabilities of the involved musculature, and in turn increase maximum dynamic strength (e.g., 1RM and mean concentric force production). In reference to the force-velocity curve, the aim is to shift force component upwards (see Figure 2). Traditionally, this was and is still often achieved through heavy load (90 – 100% 1RM) supplemented with moderate load-high volume (70 – 85% 1RM) weight training using a number of multi- and single-joint movements.
How can bands and chains be integrated into a training program to improve maximum dynamic strength? The set-up (specifically with bands) is vital, as it determines how, where, and when the resistance is applied and supplied. For example, bands can be attached to the base or to the top of the rack (see Figure 3), changing the proportion of free weight and band load in respect to the total load being moved.
When attached to the base of the rack, bands deliver the greatest resistance at the top and lowest at the bottom; but when attached to the top of the rack the bands supply the least assistance at the top and greatest assistance at the bottom. Both methods attempt to match the force capabilities of ascending strength curve movements, such as squats, deadlifts, and the bench press by providing the greatest amount of total resistance at the top and least amount of resistance and the bottom of these respective lifts.
Figure 3. Example of Top Attachment with Bands
The following inferences can be drawn; maximum strength (1RM) can be developed utilizing training loads of 70–105% 1RM comprised of free weights (65–90 % of total load) supplemented with bands and possibly chains (10–35 % of total load). The majority of maximum strength and force production improvements are anecdotal, therefore require scientific validation.
Power training, also referred to as speed-strength training, is always performed explosively and more often than not, ballistically (e.g., jumps and throws); as ballistic movements are often more transferable to sport-specific performance (7,8,9,10,17). Maximal power is produced using loads between 40 – 60% 1RM for the bench throw (power = 700–100 W; velocity = 1.2–1.5 m/s) and at or around 0% 1RM (unloaded) for the squat jump (power = 5000–8000 W; velocity = 2.50–3.50 m/s) (7,8,9,10,17).
Originally, athletes were training at Pmax to improve power production capabilities. Improvements were evident when utilizing the specific Pmax load, but were not necessarily transferrable to the lighter and heavier loads. By implementing a band width approach the full spectrum of the power-load curve can be targeted with the intent of improving overall power production (see Figure 4). Band width power training can be split into three load categories:
Figure 4. Bench Throw Load-Power Curve
For example, an athlete that produces their Pmax at 50% 1RM for the bench throw should train with loads of 45–55 % 1RM for maximal power (power = 800 W; velocity = 1.5 m/s; force = 530 N), with loads of 55–70% 1RM for upper load power (power = 600 W; velocity = 1.0 m/s; force = 600) and with loads of 30–45% 1RM for lower load power (power = 600 W; velocity = 1.8 m/s; force = 330 N) development (18). To maximize power production across the power load bandwidth three to eight sets of two to six repetitions are recommended.
To date, no power training studies have utilized supplemented bands or chains. Some strength and conditioning coaches claim that concentric acceleration, velocity, and rate of force development can be improved utilizing loads between 30 and 60% 1RM comprised of 65–80% barbell and 20–35% variable (band/chain) resistance during explosive squatting and pressing. It has also been suggested that the band assisted set-up (i.e., lightened method) may allow for even greater accelerations, velocities, and power outputs than the resisted set-up, which leads into the concept of maximal velocity training (see Figure 5).
Figure 5. Squat Jumps Using the Lightened Method
Maximal Velocity Training
Maximal velocity training is designed to minimize ground contact and contraction phase time and optimize the use of stretch shortening cycle (SSC) during ballistic and plyometric movements (i.e., bench throws, push-ups, and various vertical and horizontal jumps). Band-resisted ballistic and plyometric training is used to magnify the SSC, increasing the amount of eccentric potential energy stored in the involved musculotendon units, enhancing the rate of force and velocity development, and possibly power produced during the subsequent concentric phase (2).
Band-assisted jumping reduces bodyweight load by 10 – 20 % and has been shown to augment concentric velocity (velocity > 3.0 m/s) by reducing the contraction phase time and possibly increasing motor unit firing rates. These two forms of maximal velocity training attempt to shift the force-velocity curve to the right, increasing velocity capabilities during jumping and throwing.
These proposed benefits may potentially lead to a stronger, more explosive athlete, as many of these methods are currently being applied in elite sport-specific training environments. Strength, power, and speed-based athletes wanting to maximize dynamic strength, power, and velocity capabilities can benefit from supplemented band and chain-resisted training programs when prescribed correctly.
In order to bridge the gap between the practitioners and scientists, and to fully understand the effects of band and chain supplemented training, a number of investigations focusing on the various phases of the force-velocity continuum and band/chain loading schemes must be completed.
Travis McMaster MSc, is a Strength and Conditioning Scientist, specializing in movement mechanics and periodized training methods. He investigates the neuromuscular and musculoskeletal adaptations in athletes from a dose-response perspective. He has trained a range of athletes: from junior development programs to elite rugby and hockey players. Copyright (c) 1999-2012 National Strength and Conditioning Association. Use with permission. All rights reserved.