I was posed this question ‘ Which is more
important to improve, acceleration or maximum speed in sprinting’? The original
question was for the 200m but for the sake of this post I will keep it broad.
Well the answer, as you may well have
figured is ‘it depends’. Certainly there is a plethora of factors that will
influence all races and many intrinsic and extrinsic factors impacting each
athlete but for the sake of argument lets assume that our athletes are in a
vacuum with minimal influence from outside and our actions will have a direct
effect on the outcome.
Before we start we need to discuss the math
of speed and acceleration. Speed relates to how quickly the athlete moves. This
is done by dividing ‘how quickly’ by ‘how far’. This is important to not to
confuse this with velocity, which also includes the resultant direction. This
is not important in the 100m as the speed and velocity would be the same but
they would be significantly different over the 200m.
Speed
= Distance/Time
Velocity
= Displacement/Time
Acceleration is the rate of change of
velocity. Velocity is measured in meters per second while acceleration is
measured in metres per second per second. To determine actual rates of
acceleration, instantaneous speed is required i.e. the speed at the 10m mark.
Acceleration
= Velocity/Time
m/s to km/h is m per s/1000 x 3600
km/h to m/s is km per h x 1000/3600
But who will run the faster 200m?
These models are hypothetical and to be
accurate a coach will need to insert their athlete’s times. But let us assume
for a moment that the 200m is divided in to a acceleration phase (0 – 50m), a
maximum speed phase (50 – 150m) and a deceleration phase (150 – 200m). We also
have the average speed and the total time.
Race phase
|
Actual time (s)
|
Acceleration
- 3%
|
Max speed
- 3%
|
Deceleration
- 3%
|
Acceleration (0-50m)
|
5.90
|
5.72
|
5.90
|
5.90
|
Max Speed (50-150m)
|
9.70
|
9.70
|
9.41
|
9.70
|
Deceleration (150-200m)
|
5.30
|
5.30
|
5.30
|
5.14
|
Average speed (m/s)
|
9.60
|
9.65
|
9.70
|
9.64
|
Total time (s)
|
20.90
|
20.72
|
20.61
|
20.74
|
Therefore
if we improve each factor by a 3% margin there is a more profound effect on the
average speed with the adjusted maximum speed and therefore the total time in
this example. So the answer to this question: the athlete
who improves their average speed the most will run faster and in this example
this is achieved through improving maximum speed.
In reality this does not
happen but it is a nice controlled experiment to see effect. The goal for any
coach is to maximize their athletes potential and try to not waste valuable
time and energy on inefficient gains. In this example the coach may choose to
focus their athletes time on speed endurance and less time on pure speed
training however if the distance were changed to 60m then the most likely way
to effect average speed would be to improve on the acceleration. Conversely the
400m coach may heavily focus their attention on maximum speed as an improvement
in the acceleration phase would have even less improvement than the 200m
example.