A Survey on the Effect of Lane Assignment in Sprinting the Curve Portion of a 400m

[rainy.here]

@Sevastocrator

Lane assignments have always been of prime importance to sprinters in events involving a curve. The curve produces a biomechanical disadvantage due to centrifugal force – the force caused by changing direction from a straight line to a curved path. The centrifugal force causes the runners to expand extra energy in thrusting outward to get around a curve.

An equal amount of centripetal force (an inward pulling by the runner) is necessary to resist the outward pull. Otherwise, the force would topple the runner or force him to run in a straight line.

The outward pulling force may be reduced by the banked curves used in indoor facilities. Outdoor (flat) tracks require the runner to overcome centrifugal force by leaning on the curve, shortening his stride, and/or reducing his speed.

One may conclude that the outer lanes of the track would require less centrifugal force, since the runner has less of a curve to negotiate. Yet you find sprinters disliking the outer lanes. They believe they are the “slow” lanes.

For the number of professors in this article, I’m surprised they messed up this concept: there is no such thing as centrifugal force. It only feels like it. The centripetal force (towards the centre of the curve) is the only horizontal force acting on the runner.

Also, since centripetal force is proportional to velocity squared, using runners that take 12.35 to negotiate the curve means we can’t apply the results to someone who takes 10.35 seconds on the curve, since the faster runner must apply about 50% more horizontal force (to stay on the curve).