Everything you need to know about running faster you learned as a child. Remember that scooter you had? Or that skateboard? Think about using the scooter: you can either push with big powerful pushes, but that will make your leg tired or you can take small frequent strides to maintain your speed. When you think about running, the same strategy applies: there are two ways to go faster, one way is to move your feet quicker and another way is to take bigger strides. It is much easier to take small, frequent, rapid steps than it is to push harder. We can think about power output as a function of how quickly you turn over your feet and how much you push yourself forward. Pushing yourself forward gets tiring after a while, however increasing your foot turnover or run Cadence makes it easier to go faster.
Even if you have to think about this while you’re reading this, this is something that we automatically do. When we start off walking our Cadence might be 100 foot strikes per minute, however as we go faster and faster our Cadence increases. Eventually we can’t turn over our feet quickly enough so we have to start pushing harder with our legs. Once that starts in the muscles start to work hard, they start to accumulate lactic acid, and you start to get tired.
As lactic acid accumulates, fatigue starts to set in and further increases in speed or distance becomes limited. Therefore, it is important to know the Cadence at which you will start to fatigue.
If you have a Cadence function on your running watch this can be useful to help you set your pace. I think Cadence is more useful than heart rate because you can maintain your Cadence and adjust stride length whether you’re going uphill or staying on a flat surface. Also, the Cadence measurements from a watch seem to happen in real time. If you’re using heart rate for training your heart rate might not elevate until a minute or a minute and a half into a harder effort. By the time you realize that your heart rate is too high, you are already heading to fatigue.
So, how can we figure out what the Cadence is that you should be using for different events?
You can either look at your average Cadence for a 1-hour run, or you can test yourself on a treadmill. To test yourself on a treadmill, turn on your run indoor function on your watch and start walking at 3 miles an hour. Turn up the treadmill speed by 1/2 mile an hour every minute. Keep going until you can no longer keep up with the treadmill. When you’re done use a spreadsheet program such as Excel or Numbers to plot your cadence every minute. When you look at the graph, there should be a point at which the Cadence curve stops going up and reaches a plateau. If you look at the Graph in this article, you can see that Cadence increases until the point where it starts to level out. In this case, I inserted a black line at the plateau. The point where the change happens corresponds to the onset of lactic acid or your maximal aerobic pace. Below this Cadence you should be able to run for a while and above this cadence, you will start to get tired.
Now that you know your Cadence, you can set a metronome to that number and try to run to that beat, or you can search for electronic music that has that number of beats per minute.
When we do exercise testing in the lab, we use Cadence to determine multiple zones that correspond to the different racing and training zones you will use to prepare for the season.
The nice thing about using Cadence is that a Cadence of 170 is still 170 whether you are running on a track, a treadmill, or going uphill. The big difference is the stride length will be different on different gradients.
Set your running watch to the cadence function and use it to stay within your racing zones.
Michael Ross, MD is a sports medicine physician who has been treating endurance athletes for over a decade. He has been a team physician for numerous professional cycling teams. He also runs the Rothman Institute Performance Lab, a medical and scientific exercise testing and training facility in Bryn Mawr, Pennsylvania. He has written two books on training and sports medicine for endurance athletes as well as multiple scientific papers. He has been an invited speaker at USA cycling and consulted for several bicycle companies to provide the optimum fit. He is an avid triathlete himself who has qualified for short course triathlon nationals several times. When he is not at work or spending time with his family he can be found on the trails and the roads around Philadelphia. www.rothmaninstitute.com/physicians/michael-j-ross-md