training (also known as static strength training) involves muscular
contractions in which the length of the muscle does not change and
there is no visible movement in the joint.
The word 'contraction' signifies a change in length (shortening) of a
muscle but this does not occur in static strength training so the
preferred term is static action not static contraction. Isometric
exercises can be performed with 'sub maximal' muscle actions - which
hold a weight steady on to a side for example. Here the force is not
maximal as this would lift the weight further causing movement, change
in the muscle length and joint angle. However, isometric exercises can
also be maximal such as pushing against an immoveable object (like a
wall or heavy weight). Both of these types of isometric action can
increase strength and induce muscular hypertrophy although in practice
maximal exercises are used for strength and conditioning whereas sub
maximal exercises are used for rehabilitation.
Many sports require isometric actions such as climbing, mountain
biking, judo, wrestling, skiing, gymnastics and horse riding. But one
must be made aware that isometric exercises aren't the most dynamic
actions (which most sports are - running and jumping) so do not
increase the limbs maximal velocity and may only strengthen the muscle
at the angle at which it is trained.
How isometric resistance works
Resistance in isometric exercises typically involves contractions of
the muscle using:
body's own muscles (such as pressing palms together)
items like a wall or door
weights, weights machines and elastic equipment where the weight is in
a fixed position
plate equipment that can give a digital read out of the force.
of isometric exercises
achieve maximum muscular contraction as opposed to isotonic exercise
workout is much faster. You can do each body part in as little as a
minute (with a few seconds rest).
- It can
gain strength but only isolated to the area you specifically trained.
of isometric exercises
muscular endurance. When lifting weights (isotonic exercise) blood is
pumped round the muscles frequently and increases muscular endurance.
Isometric exercises don't produce the same blood flow.
strength during a static contraction can potentially reduce the speed
of the muscles response which may slow down your athletic performance.
- It can
be very boring!
blood pressure. Isometric exercises increase blood pressure more than
any other form of exercise which could lead to a ruptured blood vessel
or irregular heart beat.
exercise achieve gains through only 20 degrees of the angle you hold
whereas lifting weights allows you to build strength through an entire
range of motion.
tips for doing isometric exercises
- If you
have hypertension isometric exercises may be dangerous as they increase
blood pressure significantly. Even if you don't suffer hypertension it
is important to breathe continuously throughout the exercise.
- Warm up
thoroughly first as tears can still occur.
good posture throughout every movement working with a strong core. This
will prevent injury especially in your back and joints and also keep
general consensus is that to improve strength (not rehabilitation) the
most efficient use of isometrics is 15-20 maximum voluntary actions
holding for 3-5 seconds. Doing this three times a week for at least 2
weeks should show results.
joints using isometric exercises should be done through multiple joint
angles at the same muscle group to see results.
common isometric exercises are:
• The plank
• Side plank
• V-shaped hold
Other isometric exercises can be designed from such usual exercises as
the push up, shoulder raise, squat, calf raise, leg extension, hip
extension and hip abduction. Here to make them isometric you need to
hold the end position for about 5 seconds before releasing the pose.
In conclusion, it can be seen that isometric training serves a fruitful
purpose in gyms and especially for training specific muscle groups for
particular sports. It is also beneficial as a method of rehabilitation
after injury. However, precautions must be made with how the movement
is performed and in relation to blood pressure. With isometric
exercises by only focusing on a limited range of movement may not be
suitable for all.
Carter is a fully trained fitness and life coach. Visit her
website at http://www.cartercoaching.co.uk