Acceleration vs Max Speed

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.