If you run with a modern sports watch, you’ve probably noticed that we are living in the golden age of running data. After a solid long run, your Garmin Connect app serves up a buffet of advanced scientific metrics. But what do all those numbers actually mean for your daily training?

I’ve started to consider what this data might have meant in my faster days (late ‘90s and early ‘00s).  At the time, there were limited metrics available aside from a handful of high-end biomechanics labs. The data presently at our finger tips, coming from our wrist, on a daily basis is both pervasive and awesome (in the fear inspiring sense).

For years you’ve heard me and our other coaches stress the importance of pace recognition, Rate of Perceived Exertion which we use as Rate of Perceived Effort (RPE), progressive pacing with some input from heart rate as a % of maximum heart rate.

I’m super excited about all the new data available and believe that proper pacing with recognition along with forms of progressive pacing are still the most important for race and training outcomes.

But. . . the available data can no longer be ignored so let’s start to interpret some of it.

Today, we’re going to look at three of my favorite advanced running dynamics:

1. Stride Length

2. Vertical Oscillation

3. Vertical Ratio

I’ll explain what they are, why they matter, and how we can tweak your form/effort to become a smoother, more efficient, and injury-free runner.

Note:  Definitions from Garmin Human Performance Lab are publicly available and included below.

Stride Length

This is simply the distance you cover with each stride.  Of course, we don’t want long lopey strides or potential over striding to interfere with our focus. In fact a shorter stride length can be beneficial especially in the early parts of a race.  One practical consideration I have with stride length is to consider your drive at the end of races.  Often we observe max stride length at 75-85% of race distance.  One way to improve the stride length is a concomitant effort to swing your arms with strong force near the end.  If you watch World Class Marathon/10K/5K/1500m etc. runners at the finish their arm swing is almost always exaggerated compared to the start of the race.  When you swing your arms with force, your legs follow suit.

What is Vertical Oscillation?

In simple terms, Vertical Oscillation is your "bounce." It measures the amount of vertical movement in your torso with each step, measured in centimeters.

Ideally, as runners, we want our energy propelling us forward, not upward. However, we frequently see a point of frustration for taller runners here. Because taller runners have longer legs and naturally longer strides, their absolute vertical oscillation numbers are almost always slightly higher than shorter runners simply due to biomechanics. A tall runner might naturally sit around 7.5 to 8.6 cm, which can look high on paper but is perfectly normal for their height.

In my opinion, raw Vertical Oscillation metrics should not be over emphasized.  Stride length (especially at the end of a good effort) + Vertical Ratio are better indicators of proper form.

The Great Equalizer: Vertical Ratio

If you’re a taller runner looking at your Garmin data and feeling discouraged by your bounce, don't worry. This is where Vertical Ratio comes to the rescue.

Vertical Ratio takes your Vertical Oscillation and divides it by your Stride Length, expressing the result as a percentage. This metric essentially levels the playing field, factoring in your height and stride to give you a true picture of your running efficiency.

Instead of obsessing over raw centimeters, look at your Vertical Ratio percentage. Here is how the benchmarks break down:

• Excellent (Elite): Less than 6.5%

• Great: 6.5% – 8.3%

• Good (Average): 8.4% – 10.0%

• Needs Improvement: Greater than 10.0%

(Note: Many runners find they naturally bump up against "Excellent" or "Great" ratios during fast interval sessions, as faster running promotes better form! This is one of the reasons that here at  Runcoach we always suggest one or two quality sessions with intervals at faster paces each week.)

Why Does Your Bounce Matter?

Whether you're a middle-aged marathoner or an infrequent 5K racer, keeping your Vertical Ratio in check provides two massive benefits:

1. Energy Conservation

Think of it this way: over the course of 26.2 miles, bouncing an extra inch per step equates to climbing hundreds of extra feet of elevation. By keeping your bounce down, you are saving precious glycogen stores for the later miles when you really need them.

2. Injury Prevention

What goes up must come down. A higher vertical oscillation means a heavier landing. Reducing your bounce significantly decreases the ground reaction forces on your knees, hips, and lower back. If you want to stay healthy and injury-free through long, grueling training blocks, smoothing out your ride is key.

How to Improve Your Numbers

If your watch is consistently showing a high Vertical Ratio, you don't need to completely overhaul your stride. Usually, corrections only need to be made in millimeters. Here are 5 practical, coach-approved ways to smooth out your ride:

1. Run "Quietly": We love this mental cue. Next time you run, focus on making less noise when your feet hit the pavement. This naturally encourages a softer, lower-impact, and more forward-driving stride.

2. Slight Forward Lean: Ensure you are running with a slight, natural lean from your ankles—not bending at the waist. This helps direct your momentum forward rather than upward.

3. Consider a Low Ceiling as your Guide:  Pretend you’re running indoors and the ceiling is only a few inches/centimeters above your head.  Try to avoid hitting your head with each stride. (Note:  Take this recommendation with a grain of salt because the faster we run, the more bounce we will get from power.  The “don’t hit your head on the ceiling” practice is most ideal for long and easy runs not quality sessions).

4. Increase Your Cadence: The quickest and most effective way to reduce vertical oscillation is to increase your step rate (cadence) by 5% to 10%. Taking quicker, slightly shorter steps naturally flattens out your trajectory and prevents overstriding. (Aiming closer to 180 steps per minute is a great goal, though taller runners may naturally sit a bit lower).

5. Try a Running Economy Microcycle: Because faster running promotes quicker cadence and better form, mixing in shorter, faster intervals (like 200m repeats) is a great way to set a baseline of strong mechanics. Your body remembers that efficient form, which eventually bleeds into your easy runs. Many of you have heard this suggestion from me in between Marathons and other goal races.  If you’re interested in a running economy cycle, please reach out to your coach.

The Bottom Line

At Runcoach, we believe data is only as good as the human insight behind it. The next time you finish a run, take a peek at your Vertical Ratio in Garmin Connect. If the number is a bit high, try running "quietly" with a slightly quicker step on your next outing.  Check out your Vertical Ratio on the intervals of your quality sessions and you will see a big difference.

Want a coach to look at your smart watch and help you build a plan to improve your running economy? Our 1:1 human coaching team is always here to help you make sense of the metrics and achieve your next personal best.

Vertical Oscillation, Vertical Ratio, Stride Length Chart (Note:  this table was created with help from Gemini AI and reviewed by the coaches at Runcoach):

Available from Garmin publicly accessible information https://www.garmin.com/en-US/garmin-technology/running-science: