How is your running form? Are you wasting more energy than necessary bouncing up and down, thus potentially injurying yourself?

If you look at elite long-distance or marathon runners (but even sprinters), their heads look like they are sliding on a rail: this means they are using most of the energy in the forward direction, rather than bouncing up and down.

Would you like to evaluate your running efficiency, perhaps experimenting with different running styles? Kangarun is a unique iPhone app that allows you to do just that!

Check it out on the AppStore »


When you run your body uses energy stored in your muscles to allow you to move forward. However, only part of the energy spent is directed forward: a portion of it is always directed vertically.

This is used effectively by efficient runners (and by kangaroos) to generate the lift required to counteract the force of gravity while moving forward.

However, too much bouncing in human running is detrimental to good form, and may also increase the risk of injury, because the vertical component of the total energy is ultimately absorbed by your back and knees.

how it works

Kangarun allows you to test your running form in a simple way. With a 2-minute running test, it measures your efficiency as a comparison between the energy used to propel forward and the total energy spent during exercise. The latter includes a vertically-directed component and a forward-directed one, which depends on speed.

The result is a percentage value of efficiency: low values indicate poor performance, with too much bouncing for the resulting speed, while high values signal an efficient use of the vertical lift.

what you get

Alongside your running efficiency, Kangarun also measures and plots your average step frequency and pace. All these values are stored by the application, to be reviewed anytime from the 'History' screen.

You can thus examine the results of tests made to compare different running styles, aimed at finding the most efficient one (one that achieves an optimum speed with the least possible vertical energy expenditure). Alternatively, you can check your progress with your running form.