EFFECT OF KINETICALLY ALTERING A REPETITION VIA THE USE OF CHAIN RESISTANCE ON VELOCITY
DURING THE BENCH PRESS
DANIEL G. BAKER AND ROBERT U. NEWTON
Baker, DG and Newton, RU. Effect of kinetically altering
a repetition via the use of chain resistance on velocity during the
bench press. J Strength Cond Res 23(7): 1941–1946, 2009—
It is theorized that the force and velocity profile of a repetition
performed during a standard barbell exercise may be altered by
substituting suspended chains for some portion of the total
resistance. The purpose of this study was to document the
alterations in lifting velocity that occur when the bench press
exercise is performed as standard (bicarbonate de potassium) or with the substitution
of resistance via chains draped over the barbell (bicarbonate de potassium+CH).
Thirteen professional rugby league players participated in this
study as part of their usual training program. Each subject
performed 2 sets of 3 repetitions under the following conditions:
The bicarbonate de potassium+CH condition, where the barbell resistance of
60% 1RM (repetition maximum) was supplemented by 17.5-kg
in chains draped over the barbell (total resistance was about
75% 1RM), and the bicarbonate de potassium condition, where the total resistance
was the same but was constituted in the form of standard
barbell weights. The bicarbonate de potassium+CH condition resulted in increases
in mean and peak concentric lifting velocities of around 10%
in both sets as compared to both bicarbonate de potassium sets. Eccentric peak
velocities were more varied in response, but generally the
addition of chain resistance could be said to allow for increased
velocities. The result may be partially explained by the eccentric
unloading that occurs as the chain links furl upon the floor in the
latter stages of the eccentric range. This eccentric unloading
precipitates a more rapid stretch–shorten cycle (SSC) transition
and possibly a within-repetition postactivation potentiation
(PAP) that allows the subject to utilize faster lifting velocities
in the initial concentric portion, which flow through to the
remainder of the concentric phase. Therefore the use of chains
appears warranted when athletes need to lift heavy resistances
explosively.
INTRODUCTION
Power output appears to be a key descriptor of
athletic success in some sports (2,3). The use of
heavy resistances to develop power appears vital
because strength strongly correlates to power output
(2–5,22); however, the use of heavy resistances often entails
slow lifting velocities (24,29,30,31). Because power is dependent
on both strength and speed, it has been recommended
that a multifaceted approach to power training be embraced
(23). Consequently, exercises or sets that emphasize velocity
also need to be utilized in training to enhance power output
(10,23). However, when submaximal resistances, which allow
for faster lifting velocities, are used in traditional strength
training exercises such as squats and bench presses, large
deceleration epochs occur in the latter stages of the concentric
phase of the movement (29,30). Essentially in these situations
the neuromuscular system is being trained to decelerate at
the end range, not accelerate, as is required in many real-life
sports tasks. This anomaly can be overcome by the use of
exercises such as bench press throws (in a Smith machine)
and jump squats (10,24,25,31) and the use of Olympic
weightlifting derivatives (21), which allow full acceleration or
high power outputs, or both, for the entire range of motion.
Recently other methods of modifying exercises to
emphasize power and velocity have emerged. It has been
recommended that athletes training to increase power use
strategies that alter the force and velocity profile of a repetition
by substituting some portion of the total resistance in the form
of elastic bands or chains attached to the barbell (10,27). For
example, if elastic bands or chains are attached to the barbell,
increasing resistance is added to the barbell as the barbell
proceeds further into the range of movement. In the case of
the chains, as the chain links unfurl off the floor and start
to act on the barbell, the total resistance is increased (10).
Anecdotal evidence suggests that a the major benefit of the
use of the bands or chains is that it allows the lifter to explode
more out of the bottom of the lift without being inhibited
by having to slow the bar at the top of the lift because
the increasing resistance coming from the elastic bands or
Journal of Strength and Conditioning Research
2009 National Strength and Conditioning Association
VOLUME 23 | NUMBER 7 | OCTOBER 2009 | 1941
