Summer is the time for many runners to start gearing up for fall distance races. Whether you're training for a full or half-marathon, you'll be logging a lot of miles in the next 12 or so weeks and you may be wondering how you can increase your efficiency.

The simplest and safest answer: Increase your cadence.

Cadence is the number of steps a runner takes in a minute. Knowing this number is important because a higher cadence can reduce energy expenditure — and increase efficiency — while at the same time reducing your risk for injury.

The best way to determine your personal cadence is to go out for a run and count the number of times one of your feet — either the right or the left, it doesn't matter — strikes the ground over a 30-second period. Then multiply that number by two to get to 60 seconds, and by two again for both feet.

For optimum performance, a cadence of 180 steps a minute is typically the magic number. But you usually see this stride rate in elite athletes and Olympians, according to Ali Ladak, a physical therapist at MossRehab.

Most runners should aim for a cadence of greater than 160, though it varies for everyone, Ladak said.

If you have a cadence lower than 160, you could be at higher risk for injury. A lower cadence usually occurs in runners who are overstriders. Ladak compared the strides of these runners to that of a gazelle as it lopes across the prairie. Overstriders extend their legs out in front, causing their feet to come in contact with the ground ahead of the hips, which creates excessive force on the ankles, knees, and hips. A repetitive impact like this can lead to injuries including shin splints, IT band syndrome, Achilles tendinitis, or runner's knee.

Ladak did note that heel striking — hitting the ground with your heel instead of midfoot — isn't necessarily a problem. However, the low cadence and overstriding that heel striking can often be coupled with are what puts runners at increased risk for injury.

How to improve your cadence

If your cadence is lower than 160, your goal should be to gradually increase your current cadence by 5 percent.

But don't rush the process.

"The most important thing is that you want a minimum and gradual change, because that could increase forces on other parts of the body," Ladak said.

It can take six to eight weeks for your body to adapt to a new rhythm.

Ladak recommends the following strategies to increase your cadence:

  • Use a metronome to keep your desired pace. Metronomes are devices that can be set to produce a certain number of beats or clicks per minute. Simply set the metronome to your desired cadence and follow it on your run.
  • Wear a fitness tracker or GPS watch that will monitor your cadence for you. Some will even coach you on how to hit your goal cadence. Certain phone apps also do this.
  • If you love to listen to music while you run, download a music app that allows you to customize the beats. Apps like Rock My Run let you pick songs that help you maintain your cadence.
  • For a low-tech approach, try visualizing yourself running in a box. Confining your mind to a small space will help you reduce your overstride.