Page 4 - Chapter_12

when a person pushes a concrete wall, it The advantages of isotonic exercises are
remains stable, so no work is accomplished. enhancement of coordination and strength,
The main advantage of isometric exercises development of endurance and speed and
is the strengthening muscles due to longer increase in length and flexibility of muscles.
duration of the systematic contraction with These exercises also require specialised
relatively little loss of energy. These exercises equipment and consume more energy. These
can be performed any where as they do not are more prone to injuries, so it is safer to do
require any sports equipment, nor are they them under the guidance of a trainer.
time-consuming. These exercise should be done isokinetic exercises
with full knowledge of technique otherwise
they may injure you or cause any harm. They In 1968, these type of exercises were proposed
are also not prescribed for children. by James Perrine. In these exercises, the muscles
contract with greater force through every point
isotonic exercises in the range of motion. They involve specific
The exercises in which muscular effort results muscle contractions that of motion. They
in the movement of an object on which force involve specific muscle contractions that are
is applied called isotonic exercise. The term executed with the help of complex equipment
‘isotonic’ is derived from two Greek words ‘iso’ called dynamometers. The resistance through
and ‘tonos’, here ‘iso’ means equal and ‘tonus’ out the movement of muscles remains the
means maintaining equal tone. The resistance same. In isokinetic exercises, resistance is
changes with the angle of point, while remaining applied through out the range of motion and
constant in terms of force. Isotonic exercises the contractions are done at a dynamic preset
accomplish work, as both muscles and joints fixed speed. Therefore, the speed remains
move and change their direction. Examples of constant, even if the amount of force applied
these exercises include push-ups and pull-ups varies a per the strength and ability of the
weight training, squatting, running etc. individual doing the exercises.
There are two stages of isotonic exercises, These exercises are considered the best
on the basis of contraction i.e., concentric and for improving explosive strength and strength
eccentric. In concentric contraction, the muscle endurance. The main disadvantage is that
is shortened to produce force e.g., biceps cure. these exercises can be performed with the help
In the eccentric contraction, the muscle under of specified machines, which can be costly and
version is lengthened, as observed during are not found at fitness centres and gyms. They
lowering weights. remain available only in rehabilitation centres
and specific training labs.

Isokinetic Exercises Isokinetic exercises

4 Physical Education