A Gift And A Curse –
Full Range Of Motion
Loading and fatigue
aside, the amount of tension a muscle is under will vary based on the joint
angle, and angle of contraction, meaning the same muscle can, and will, be
under more, or less, tension at different ranges of motion during the exact
same movement. Thus, performing a full range of motion can facilitate the development
of muscular imbalances, especially with an overreliance on compound movements.
This is not to
suggest the removal of compound movements in favor isolation movements, as they
are susceptible to creating imbalances as well, albeit on a much less
noticeable scale, but rather to keep a keen eye on possible imbalances that can
result from performing a lot of compound movements through a full range of
motion. Even when imbalances occur, it is not always completely necessary to
remove the (compound) movement that caused it, as it’s not necessarily the
movement that caused it, but rather the way in which it was performed that
contributed to the imbalance.
Because different
muscles are under greater levels of stress at differing ranges of motion, especially
during compound movements, modifying the way in which the exercise is performed
can help correct the same imbalances that the movement created in the first
place, by simply emphasizing the range of the lift in which the targeted muscles
are most active.
Double Contraction
The double
contraction technique is exactly as it sounds – a full rep is performed,
followed by a partial rep at a specific range of motion, so that twice as many
reps are performed at that range in comparison to those performed through a
full range. This is one of the most effective ways to correct imbalances
created with full range of motion training, or simply place a muscle under
greater levels of tension than would happen under normal conditions to
stimulate growth.
The range in which
the double contraction partial rep is performed should obviously be determined
by the goal, and can be applied to any exercise, but two movements in which
this technique is especially effective are the squat, and all barbell presses.
Double Contraction
Squats
The vastus medialis
oblique (VMO) head of the quad is relatively underdeveloped in relation to the
other heads of the quad, primarily as a result of it being most active at end
ranges of knee flexion and extension – two positions in which the knee is
rarely ever optimally loaded. In this case, a double contraction in the bottom
range of the squat doubles the time that the VMO is under optimal tension, as
the amount of weight that can be used is limited to how much can be lifted in the
weakest range, which is the range in which the VMO is most active.
Double Contraction
Presses (All Angles)
Barbell presses are
multi-phase lifts in which the tension shifts from one prime mover to another –
at the bottom range the chest/shoulders are the main driver, at the top range
the triceps are the main driver. Therefore, a double contraction at the bottom
range doubles the time in which the chest/shoulders are under tension, while a
double contraction at the top range doubles the time in which the triceps are
under tension. Obviously the angle of the press, along with the grip width,
will determine how heavily emphasized the chest, shoulders, and triceps are
recruited.
If you have any
questions about the double contraction technique, feel free to contact me
at ben@paramounttraining.ca. I'm available for
online consulting and personalized program design, as well as one on one
training if you are located in the Greater Toronto Area (GTA).
What about 1 1/4 reps on the CNS? Obviously resistance training in general allows our motor units to become more efficient, but would 1 1/4 reps achieve this better than normal reps?
ReplyDeleteThanks. Very nice post. Your web site is very beautiful.
ReplyDeleteJob Provider Contractor