The rules for warm-up and
cool-down are simple. A gradual progression in intensity of
exertion should introduce the fitness session. At the end
of the session, there should be a tapering-off period, during
which the body returns to normal. Actually, authorities disagree
to some extent on the need for a warm-up and cool down. But
most feel that a pre-exercise warm-up should be mandatory
for everyone taking part in demanding exercises. For those
who have not exercised seriously for a long time and who are
restarting, the warm-up should last 10 to 15 minutes. For
those in better condition, the warm-up can be shorter, even
as little as 5 minutes.
An effective warm-up period
has several physiological effects. For one thing, it stretches
ligaments. The warm-up also raises the body temperature and
increases cardiovascular activity. In all such ways, the warm-up
prepares the body for exercises.

The warm-up begins, for best
results, with light, rhythmical exercises performed at a slow
pace. Stretching and deep breathing both loosen the muscles
and increase the body’s oxygen supply. Stretching also makes
deeper breathing possible.
Most sets of warm-up exercises include about for or five very
simple movements. The body should be sweating lightly when
the set is done. A typical group of four exercises is as follows:
1) The Deep-Breathing exercise
requires that you rise on your toes, inhaling deeply at the
same time. First extend your arms straight out to the side.
While breathing in and rising on your toes, raise your arms
from shoulder level until your hands come together over your
head. That position should be held for a moment or two. Then
lower your arms to your sides and exhale while returning to
the flat-footed standing position. Six to a dozen repetitions
will suffice.
2) The Arm Rotation exercise
calls again for extension of your arms straight out to the
sides from your shoulders. The hands are then rotated in circles
about a foot in diameter. Your hands should describe 20 circles
while rotating forward and 20 more while rotating in the other
direction.
3) In the Body Rotation exercise,
after placing your feet wide apart and bending forward at
the waist, rotate your body from the belt up in slow circles.
The upper body should describe circles large enough to stretch
all the affected muscles. You can rotate five times in one
direction, five more in the other.
4) In the Bend and Bounce,
bend far over with your legs spread apart. Try to touch your
fingers to the ground three times in front of your right foot,
then three times in front of the left. The touching should
be done with downward bouncing motions of the body. The beginner
may want to bend without touching the ground at all-just bouncing
and bending low. The bend and bounce should stretch the back
muscles. The tensions of the muscles should be increases daily
until flexibility returns.