The follow through phase begins with a streamlined glide and
this is an integral component of the swim turn as the velocity of the push off
is greater than swimming speed, and strokes should only resume once the
velocity has decreased to swimming speed. There are two determining factors
that affect glide performance:
·
The initial wall push-off velocity
·
The hydrodynamic drag that acts to slow the
swimmer down
The follow-through phase is affected by the velocity of the
glide, body form, degree of streamlining and the glide depth (Little, Lloyd,
Blanksby & Elliott, 1999). A later
study by Blanksby, Elliott, Lloyd & Lyttle (2000, p. 801) acknowledged that a
widely held opinion is that the lateral streamline and lateral dolphin kick
position produces faster turns. However, their study showed that no one kick
resulted in any significant advantage over the other and no significant
difference was found between the prone and lateral streamline glides at any
speed.
In freestyle, most swimmers take their last breath one
stroke cycle before reaching the wall. In his study on the relationship between
the breath holding times and the biomechanical events of the turn Craig (1986, p. 405-406) observed
that the breath holding time was longer in the freestyle events than in
butterfly and the backstroke and this was due to the necessity of beginning the
breath apnoea before reaching the end of the pool. The relationship between the biomechanical aspects of the turns and the gas exchanges during the brief
period of breath holding suggests that swimmers can maximise the period of
increased velocity of the push off without being limited by the consequences of
the apnoea. While the period without a breath can be distressing relief can be
expected after the first inspiration of air and swimmers should utilise optimal
biomechanical manoeuvres for turning without concern for the physiological
stresses associated with the necessary period of breathing apnoea.
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