In terms of running, cadence refers to your stride frequency or the number of steps you take per minute while running.
For a number of different reasons it is generally agreed that running with a faster cadence will reduce your risk for injury and improve the overall efficiency of your performance.
This is because a quicker cadence is associated with shorter strides, lessened impact and the ability to best maintain forward momentum. However, it should be noted that these theories are based on anecdotal evidence as only a few small studies associate a slower cadence with increased risk for injury.
Most experts agree that an ideal running cadence falls somewhere around 180 steps per minute or more. This was discovered by renowned running coach and researcher Jack Daniels during the 1984 Olympics when he counted the strides of distance runners while they raced. His findings revealed that almost every single one ran at a rate of at least 180 steps per minute.
One way you can calculate your cadence is by counting your steps for 30 seconds while running and then multiplying that number by two. Another technique described by Dave Munger, author of Science Based Running, involves calculating the time it takes for your right foot to take 30 steps while running and then dividing 3,600 by that number. For example, if it took your right foot 20 seconds to take 30 steps, your cadence would be 180.
Munger notes that the cadence of most beginner runners usually falls somewhere around 160, which is why many are encouraged to implement training techniques that will help increase their steps per minute and as a result, potentially reduce the risk for injury, increase speed and improve the overall efficiency of their running.
To practice your running cadence you can work with a metronome in order to match your steps to the beat. You can also use music as a gauge for your pace using an app like Cruise Control that will help you find songs with beats that will match your desired pace. (See: Can Music Make You Run Faster?)