Using Video Analysis and Garmin Run Dynamics to Run Faster

What makes you run fast?
 
It’s widely understood that technique plays a huge part in swimming speed.  Swimmers constantly practice drills to optimize their position and movement in the water.  Yet running form and technique is also critical yet rarely analyzed or optimized. 
 
In this blog I will share some great running insights that I’ve learned by combining video analysis with Garmin’s powerful Run Dynamics
 
To record Run Dynamics, you need to use wear a Garmin HRM heart rate strap and use the correct Garmin watch.  Sensors in the strap measure the following KPI’s (key performance indicators):

• Cadence: Steps per minute.
• Vertical Oscillation:  How high up you bounce when running.
• Vertical Ratio:  How far forward you move vs up (Vertical Oscillation divided by Stride Length).  Lower number is better.
• Stride Length
• Ground Contact Time:  How long your feet touch the ground, shorter is better.
• Left to Right Balance: Comparing left to right contact time.
• Run Power:  How much energy you are using when running (this requires a seperate app and works only on certain Garmin watches.

 
Athlete Testing
 
Like any study you need to collect data before you can see trends and draw conclusions.  I had our group of six athletes run a series of tests while wearing the HRM strap and Garmin watch.  The group contained a good cross-section of athletes, 2 women, 4 men, beginner to elite, ages 35-62.
 
Everyone first ran at endurance easy pace.  We the ran two half mile repeats at the athlete’s 5K pace.  And finally, a quarter mile fast at their mile pace.  I entered the data into a spreadsheet and some clear patterns emerged.  Not only can you common patterns of when each runner ran at a faster pace but you could also see how the metrics were different between the athletes. 
 
Common denominators to Running Faster:  When each athlete stepped up their speed the following metrics changed…

• Cadence Increased
• Vertical Oscillation Decreased
• Vertical Ratio Improved
• Ground Contact Time Decreased

 
What Metrics did the Fastest Runner Have?

• Cadence (2nd highest) at 203
• Longest Stride 1.50 meters.
• Lower Vertical Oscillation 7.01 cm.
• Lowest Vertical Ratio 4.1
• Shortest Ground Contact 1.69 ms.
• 50/50 Left to Right Balance

 
 
Examples
 
Left to Right Imbalance:  A year ago I used slow motion video to show an athlete that his right foot pronated excessively with ground contact.  But Run Dynamics measured his run balance at 54 Left – 46 right, which was much more than I suspected.  Research has shown that only a 1% imbalance can have a 4% decrease in run efficiency.  You can clearly see the variability in the runner’s stride and contact time in the graph in the photo gallery. This athlete is starting treatment with a physical therapist to correct the imbalance.
 
This is a great example of how both Run Dynamics and Video Analysis work together to understand the problem.  The Run Dynamics clearly point out the severity of the problem but not the cause.  The video show that excessive pronation of the right foot is the cause.
 
Vertical Oscillation Example:  There is a direct correlation between slower speed and high vertical bounce or oscillation.  This was clear when every athlete ran faster in our test series.  One athlete has a background in gymnastics and pole vaulting is used to springing up when she runs.  Run dynamics confirmed that she had the highest vertical oscillation.  This knowledge is huge!  Just by working on decreasing this metric she will become a faster and more efficient runner.
 
Ground Contact Time Example:  There is also a direct correlation of faster speed with a short ground contact time.  This is measured in milliseconds and it’s amazing that Garmin’s Run Dynamics can capture this.  When I look at the slow-motion video of the runner with the longest ground contact, I can see that her foot strike starts with the heel and is slightly in front of her knee.  This robs rebound energy and increases ground contact time.  We are working on more forward hang time, not rushing her stride and landing mid-foot under her knee.
 
Conclusion
 
For over 20 years I’ve used Dartfish motion capture software to analyze and optimize a cyclist’s position during bike fitting.  I’ve also used this technology to help athletes see and understand their run mechanics.  But Garmin’s Run Dynamics raises the bar to a whole new level!  The data enables you to measure key metrics and also track them every workout to see if you are making progress.
 
Run power is the next frontier, stay tuned a will be covering that in my next blog!