Running Economy
Running economy is how much energy it takes you to run. The better your economy, the faster and further you can run. Running economy is obviously determined to some extent by biomechanical efficiency. Changes in things like arm movement and the amount of "bounce" can have a direct impact on running economy. However there is some evidence that biochemical changes may have a significant impact on running economy. For instance slow twitch muscles require less oxygen for the same level of work as fast which muscles do. The two charts below show the V̇O2max and running economy of Paula Radcliffe over a 10 year period. Over that time Paula Radcliffe's race performance dramatically improved even though her V̇O2max did not. This suggests that for elite athletes at least, improvements in running economy are critical.
Measuring Running Economy
To measure running economy you need to calculate the energy used, which normally requires wearing a mask linked to a system that works out the oxygen usage. This is cumbersome and awkward, so I use a simpler approach based on the number of heart beats per mile. The Running Efficiency Calculator covers the details of the calculation. The combination of running economy and V̇O2max is VDOT, which is a useful measure of a runners ability.
