3.7.2 Centre Of Gravity
Young athletes also need to understand the concept of the ‘Centre of Gravity’, which plays an
important role in many different events within track & field athletics. A simple exercise to find the
body’s centre of gravity can be seen below.
The young athlete lies on a bench on his or her front and finds the point where the body is balanced
with neither forward nor backward movement. Once the body reaches the point of balance, the
centre of gravity has been found. If the young athlete sweeps his or her arms forwards towards a
position in front of the head, the top part of the body will then move down towards the ground.
The young athlete should now lie on the bench on his or her back and once again find the point where
the body is balanced. If the young athlete slides down the bench with his or her lower body, the legs will
move down towards the ground and the centre of gravity has then passed over the edge of the bench.
Compare the weight of a 3kg medicine ball with the weight of a young athlete. Although the
medicine ball is quite heavy to lift, the young athlete’s body weight can be 12 to 18 times heavier, so
the legs are constantly carrying a large weight. Ask the young athlete to walk on tiptoe without a
medicine ball. Lifting the body weight should be quite easy as such weight is normal to the legs.
Then ask the young athlete to carry a 3kg medicine ball, holding it out in front. The legs should feel
the difference when trying to move around with 3kg additional weight as more work is been done
by legs and hips to stabilise the shift in the centre of gravity of the body.
Another easy exercise that highlights the difference in effort required to lift the body with additional
weight is as follows. The young athlete should crouch down and then move into a standing position.
Then holding the 3kg medicine ball out in front, the young athlete should be asked to perform the
same task. The additional effort required by the legs to move the body weight and the medicine ball
to a standing position should be quite noticeable and once again due to the effort required to
stabilise the shift in the centre of gravity.
The vertical jump, explained in section 5.2.1, is a simple indicator of how far the centre of gravity has
been raised from the floor.
Warm-Up & Cool-Down Activities
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WEB COPY
©EVEQUE
WEB COPY
©EVEQUE
Move arms over head
Bench
Slide down bench
Bench
