Running Form Test

The number at the very top of the assessment page is your overall score, which reflects your biomechanical performance and risk of injury.  A higher score reflects a better and safer overall running economy.

Running form describes the runner's general gait while running. A runner with good form can run more efficiently, with less effort required to propel them forward. The two most common forms of running are Aerial and Ground, but neither is necessarily "better" than the other, as each has different strengths and weaknesses.

Ground Runners keep up their pace while using less energy.  To do this, they utilize a stride-propulsion technique that increases ground contact time by landing with the foot further away from their center of mass. Although some energy is lost during the landing, it is less demanding for the muscles compared to Aerial Runners.

Ground Runners have shorter time spent in the air, greater leg compression, and longer ground contact times. They also tend to have a more rear-foot strike, as well as a more erect upper body and a larger arm swing. They have smaller peak ground reaction forces, and maintain a lower center of mass.  They should be aware of the following:

• Avoid overstriding (landing at an excessive angle, with your feet far in front of your center mass) to lessen the impact force on the joints.
• Reduce vertical stride ratio to Improve overall efficiency (having a slight forward lean is the most effective way to do so).
• Engage in bodyweight strength training and joint stability exercises.
• Rest and adjust your workout if you experience any joint pain or discomfort.

Ground Runners' joints are vulnerable to damage. The impact of a Ground Runner's landing (1.5–3 times their body weight) is more noticeable than that of an Aerial Runner. Repeated hits during long-distance running can result in stress fractures, meniscus tears, and other overuse injuries to the bones and joints. As a result, Ground Runners should avoid overstriding, take a break or modify their training plan when joint pain or discomfort arises, and engage in bodyweight strength training and joint stability exercises. 

In contrast, Aerial Runners tend to use their increased bounce to recycle the energy accumulated in the legs and utilize it to propel them forward. When the leg muscles are activated prior to landing, energy is fully absorbed during the landing phase and released during the takeoff phase. This method reduces energy loss during landing but requires more muscle activation.

Aerial Runners spend more time in the air, have greater center of mass displacement (bounce higher in the air), and have shorter ground contact times. They also tend to have a slightly forward upper body lean and a smaller arm swing. They have greater peak ground reaction forces and leg stiffness as well.  They should be aware of the following:

• Avoid excessive vertical stride ratios and overly bouncing movements.
• Increase leg stiffness to reduce energy loss by performing lower leg and foot arch strengthening.
• Rest and adjust your workouts if you have achilles tendon pain or discomfort.

The muscles and tendons of Aerial Runners are vulnerable to injury. Aerial Runners use their leg muscles more, absorbing energy during the centrifugal process of landing and releasing energy during the centripetal phase of launching off the ground. The load on the Achilles tendon, calf, and arch is increased, and repeated stretching can lead to Achilles tendonitis and plantar fasciitis. Engage in regular lower leg and arch of the foot strength training and make appropriate rest and training plan adjustments if you experience discomfort or pain in your muscles and tendons.

The central data points for the Running Form Test involve three criteria: Skill (ground time and stride data), Strength (leg power), and Balance (left- or right-foot dominance).  The scores that you see for each criteria are averaged from the data collected during the 5-minute period of steady running.

Skill is comprised of three data points: Ground Time, Strike Angle, and Stride Ratio.  Ground time is just what it sounds like: the amount of time each of your feet are in contact with the ground.  Strike Angle is the angle of your foot when it makes initial contact with the ground.  And Stride Ratio is determined by a formula related to stride height (how much "bounce" you have off the ground) and stride length (how far your foot travels between each step).

The second category, Strength, is made up of two data points.  Leg Stiffness measures how quickly your legs rebound after making contact with the ground.  Peak Ground Reaction Force uses a complex formula to measure how strong your legs are when pushing off the ground.

Lastly, Balance is measured by the percentage of ground contact time spent on each foot.  Running is typically a symmetrical movement, so imbalances may be caused by uneven roads, curves, or injury.

Based on the results of your test, the summary section will give you a quick recap of your results and general suggestions for how to improve your running form.  We recommend working with a coach for further insights and actionable steps to make improvements.

You can reach out to one of our COROS Coaches for more information by emailing coach@coros.com.

It is possible to change one's running form. A runner's natural running form remains stable unless their ability changes. You may progressively move from ground to aerial type as your skill and pace increase. This is due to an increase in allotted pace, which can only be achieved with an aerial-type movement strategy (this is not true for all runners however, and the optimal running form can depend on the individual and their own unique body mechanics). This can be visualized as walking with constant acceleration and then having to start running because walking is no longer able to perform movement at this pace.

If a Ground Runner feels that they are reaching a bottleneck in their skill and pace, they can attempt to modify their running form by using a progressive form and strength training parallel approach. By using techniques like high knee drills, foot landing training, and cadence training, you can gradually increase your running form score while familiarizing yourself with the Aerial type of leg movement. We recommend four weeks of strength training to strengthen the foot arches and calves prior to starting the form training. Foot arch strengthening can be achieved by rolling a towel with the toes or performing self-weighted heel lifts, in addition to other jumping exercises like jumping rope. By using the previously mentioned techniques, runners can reduce the risk of injury by gradually and safely modifying their running form and strengthening the muscles related to the adjustment from Ground to Aerial running.

In order to provide accurate results, the Running Form Test has a specific pace range and stride frequency threshold.  If a runner is unable to stay within the required pace range and/or their stride frequency varies too much over the course of the test, the algorithm will automatically filter out this unstable data.  If not enough consistent data has been collected, the runner may fail the test.

The pace range during the 5-minute steady effort should be similar to your marathon pace.  Typically, the faster you run, the better your running form becomes, since your body mechanics become more efficient to gain speed.  This is why the test requires a certain pace range for the running form analysis.  If the current pace feels too fast, consider adjusting your 10k time when the watch prompts you prior to starting the test.

At this time, the Running Form test can only be performed when your COROS watch is paired with either the COROS POD 1 / 2, and cannot be performed using any other 3rd party device.