IMPROVE with Stryd

Runners are continually evolving. With every step of training we influence our performance. The intensity and duration of our runs determine the type of runner that we become. Stryd’s IMPROVE Training tools in PowerCenter identify your core running characteristics and track your training over time so that you can continue to improve and evolve into the best runner possible.


Stryd Runner Profile

Identify the key limiters in your training. Focus on your Metabolic Fitness, Muscle Endurance, and Muscle Power. Metabolic Fitness is your overall current fitness, in terms of both metabolic and aerobic performance. You can build your current fitness to its ceiling in a relatively short period of time. Moreover, it is possible to slowly raise your overall fitness ceiling with consistent training. Muscle Endurance is your ability to keep running. Your ability to run long should be improved slowly. Research recommends increasing by ~10% each week, and a single long run should not be more than 20-25% of your total weekly load. Muscle Power is your instantaneous power, and it is directly linked to running economy. Improve the strength of your muscles, the stiffness of your tendons, etc., and get the most out of each and every step.

Really interesting addition / tool, which can really help to indentify some weak spots or game changer for reaching the next running level.

Training Optimizer

Each of these characteristics can be developed with specific types of training. Identify the characteristics which present the best opportunity for improvement and highlight the types of training that will be best for developing them. For example, if your weakness for a 5k target race is Muscle Power, you should slowly begin to add hill sprints, speed work and supplemental training (such as weights, drills and/or plyometrics) to your routine.


Training Power Heatmap

Get a better understanding of how your training has influenced your current Runner Profile. A visual description of your running history in terms of both intensity (power) and duration. Bright red “hot” areas indicate combinations of power and duration that you frequently achieve in your training. Dark blue areas occur less often.

The Training Power Heatmap has two primary purposes: 1) a time-in-zone comparison and 2) the maximum power that you have sustained in your training. The simple rendering of your time in zone allows you to quickly identify how you have been spending your time while training. It helps you to quickly determine if you have been targeting the correct running intensities for your target race. Additionally, the Curve Power will always display the maximum power that you have achieved in your training for that given duration. Use this information to determine what you are able to accomplish in your next race!

Fabulous enhancements – well done, guys!

Adjust your Training

You can apply these new insights to your training today! Start by building up your limiters. First focus on the workouts that address your weaknesses. For example, if you are strong in Muscle Power, but Metabolic Fitness is relatively lower – begin to shift your focus towards intervals and threshold workouts. Keep in mind that as you focus on weaknesses, they will take a bigger toll than workouts that build upon your strengths. Slowly build the volume of these workouts over the course of several weeks, and be sure to take your recovery seriously. Find the right balance of adding workouts that focus on your weaknesses without creating a high level of fatigue, which limit adaptations.

While Running Stress Score (RSS) is not a new feature for Stryd, it is an important element to consider for your training. Too little stress will limit your ability to reach your potential, too much and you increase your risk for injury. Monitor your overall training stress so that it builds slowly and stays consistent through the meat of your training, and when it is time to taper you are fresh and honed for race day.

Stryd is the Ultimate Training and Racing Technology and is available for $199 at


Guest Blog: Believe in Power

Stryder Akhil Viz graciously lends his experience Running With Power to the Stryd Blog.

As a triathlete, running is a major component of my training. I got hooked on to triathlon towards the end of 2011 when I did my first Sprint triathlon and immediately decided I would race in an Ironman ten months later!

I was a self-coached athlete at first. I figured my way through the sport by asking other experienced triathletes for their advice and scavenging through the Internet to soak in as much information as possible. I had a basic heart rate monitor and stopwatch to record my training—no other gadgets.

I had read plenty of articles and journals regarding the benefits of training with power when it came to cycling (back in 2011 there were no power meters for running). Some of the benefits are:

  • Power provides instantaneous feedback on your output and therefore removes any guesswork on how hard you are working.
  • Power is unaffected by your cardiac health (which does affect heart rate).
  • Power enables you to track performance consistently and comparably over a period of time.

After three years into the sport I invested in a power meter! Yes, it took me that long, but let me tell you that it was one of the best investments I’ve made (alongside purchasing a foam roller :-p). I noticed improvements of over 40 seconds in my 40km cycling time trial and it was all down to the fact that I was better able to train at the right intensity every single time I rode my bike.

When I heard of Stryd, I knew I had no other choice but to get my hands on one of the Stryd power meters. And, similar to my cycling performance, I’ve seen substantial improvements in my running. I’m not just saying it for the sake of it but I have data to support my statement.

I received my Stryd power meter in December 2016 and it was as if Christmas came early for me! I immediately downloaded the app and registered my profile on the Stryd Power Center. Two months later I ran my first race of the 2017 season—the Surf City Half Marathon in Huntington Beach, California. Not only did I beat my previous half marathon time by three minutes, I also set PBs for my 5km, 10km and 10 mile splits! How did I use the Stryd power meter during my training? How did I pace myself during the race?

Using The Critical Power Test Method

The Stryd Power Center has a feature called the “Critical Power Test Method.” The feature provides the options listed below to enter data from a test run to determine your Critical Power and your power zones:

  • 3-6 lap test
  • 3-9 minute test
  • 5km estimate
  • 10km estimate

Before I continue, I would like to clarify that Critical Power is the power you can sustain for a long period of time (anywhere between 30mins to two hours, and normally defined as one hour).


My advise to you is that if you are training for short distances, use either of the first three options of the Critical Power Test Method. If training for longer distances such as half or full marathons, I recommend using the 10km estimate.

This is because you are likely to run harder if you know that you are only running for a short period of time. Therefore your Critical Power and subsequent power zones will be higher than needed if training for a half or full marathon.

Set Your Power Zones

I used my previous 10km PB to determine my Critical Power and power zones (see screenshot below). Knowing my power zones, all I had to do was run within those zones. It’s as easy as that!


My winter training consisted of four runs each week (in addition to my swimming and cycling training). I did a steady run every Tuesday and Thursday evening for 70 minutes. Every Saturday I would do a short 15-20 minute run at threshold after a 3-4 hour bike ride. Sunday mornings were reserved for my long runs (2 hours). All my steady and long runs were performed at an approximate average power of 240 watts. My short run on Saturdays I tried to keep at 260 watts.

Below is a screenshot from a steady run I did on January 12th, 2017. You can see that I maintained an average power of 239.9 watts and that my power was consistent throughout most of the run (see the profile of the graph).


Consistency Is Key

Once you’re dialed in with your power zones, the next important step is to be consistent. Not only should you be consistent with the number of training sessions you perform each week but also with remaining in the power zones when you train. Even if you feel that you can run harder, you must control yourself and remain within the power zones. Don’t forget that for long distance running, the essence of the steady run is to improve aerobic capacity and develop your musculoskeletal strength. This can only be achieved at moderate intensities.

Preparing For Race Day

I’m sure you’ll get to the big day feeling very energetic, well rested and determined to record a new PB! With all those miles behind you, all you really need to do is use your Stryd power meter to monitor your power and pace during the race.

When I ran the Surf City Half Marathon, my aim was to run within my threshold pace and power. I targeted a power of 270 watts (3:50-3:55 min/km pace) based on the calculation from the Critical Power Test Method (see above). The calculations were spot on as I was able to hold that power and pace throughout the race! The screenshot below shows the data. The graph shows how I held a constant power throughout the majority of the race.


I ran my fastest half marathon and in the same race I set PBs for my 5km, 10km and 10 mile splits! I was truly empowered by Stryd!

The Proof Is In The Pudding!

This advancement in technology is phenomenal. Using a power meter can substantially improve the way in which you train and race! Please don’t get me wrong; I am not encouraging you to simply follow the numbers on your watch and forget about your running technique or how you feel during your training sessions. The message I want to get across is that the Stryd power meter is an extremely useful tool and should be used to guide you—not dictate you!

If I can improve my running performance, so can you! Be consistent, train smart and enjoy the process—the results will follow!

Buy Stryd Today

Training Peaks Run with Power Workout Export to Garmin Watch

The following article was republished with permission from Peaks Coaching Group. Written by PCG Elite Coach and Stryder, Rachel Zambrano, This tutorial will take you step by step in creating a run workout with power targets, exporting the file, then importing it to a Garmin watch for use outside, or on a treadmill.

As of the writing of this article, there are two problems that, while this is still a viable solution, make this imperfect at best. The first issue is that the Garmin does not display power from the Stryd foot pod while viewing the workout steps during the workout. It does, however, display power from the IQ field from Stryd, so while it makes it a bit challenging, it is still usable data. The second issue is that the power zones displayed on the watch itself are much wider than the actual run power zones are. The zones on the watch reflect cycling power percentages rather than run percentages, and I suspect this may be due to a limitation with the Garmin software. The workaround for this is to target the center of the zone displayed by the watch. If you can work through these two issues while we wait for Garmin to upgrade their software to handle running with power, then continue reading through the rest of the article to find out how to write a workout and get it into your Garmin watch.

From your Training Peaks account on a computer, open a run workout. You should see something similar to the screenshot below:

Click on “Build Workout” and it will bring up a few options for you to choose as to how you want to build your workout. Select either time or distance for your intervals, but make sure that you select “% of Threshold Power” and click “Continue.”

Start dragging and dropping from the blocks above with the blue squares to the line with the workout graphic on it. It’s best if you play with this a while and get familiar with it before you decide exactly what kind of workout you want to write.

As you can see, you can change the variables and the percentages. I use the Zambrano Run Power Training Zones for all my workouts. They are:

Z1 (recovery) < 82%

Z2 (endurance) 82% – 88%

Z3 (tempo) 89 – 95%

Z4 (threshold) 96% – 104%

Z5 (anaerobic) >104%

Keep dragging and dropping to build your workout. Here, you can see I’ve inserted two step intervals and adjusted the percentage to represent low Zone 4 repeats.


Now, I’ve given my workout a warm down.


When you’re done writing the workout, and you’re happy with the way it looks, click “Save & Close.” Then reopen the workout and you should have something similar to the screenshot below:


Immediately above the workout graphic, you can see the “Export Workout File” button. IMPORTANT – before you export the workout, make sure it has a name. In this case (and not on the screen shot), I named this workout “Drill.”


When you click the button to export your workout file, you’ll be presented with the options below:


Since we’re transferring this file to a Garmin watch, you’ll need a .FIT file. Garmin has a link here where you can get some additional help beyond the scope of this article, but once you click the .FIT button, you’ll have a file download to your computer.


Leave your screen the way it is and plug your watch into the computer. You won’t need to open Garmin Express just yet. When the watch is plugged in, open your file explorer and navigate to the following pathway within your watch (see the address bar in the picture below):


Hover your mouse over the file at the bottom of the screen on your computer, grab it and copy it into the folder you see above. If you know how, you can simply drag and drop it into the file explorer window. When the file is done being moved or copied, leave your watch plugged in and open Garmin Express.


Make sure your watch says that you’re up to date.


At this point, you can eject your watch from the computer, and you should see your watch updating:


Before you select your workout, you’ll need to select your activity. Make sure you’re in “Run” or “Run Inside” mode on the watch. Once that’s done, go to your menu and select “Training.”


Go to “My Workouts.”


Select “Running.”


Then, choose your workout, in this case, I named it “Drill.”


Then, get ready to start.


Remember, in order to make this work, you’ll need to target the center of the power zone displayed. In this case, 176 watts (if you go back and check, you’ll see that was the original power in the first step of the workout). If you want to share this file with others, and have it share the proper way to change targets so it is appropriate for other athletes’ power zones, you’ll need to share the file from within Training Peaks itself.

Want to export the workout file to another program or computer than a Garmin? Use this link to help you get there!

STRYD Power Averaging

Better Pacing With Stryd

What is one of the major keys to training with Stryd? Consistency. It is important to keep a consistent power on race day to run your best race. You know what power you need to aim for on race day. The challenge is: how do I stick to this power throughout the whole race?

We have a new tool for your Garmin watch: Power Averaging. Power averaging lets you see your average power. This means you can focus on consistent power and pacing to keep that steady power you need to have your best race yet. The shorter averages are useful for minimizing your step-by-step variation while the longer averages are used to focus on your overall goal. You can choose between:

  • 3 second average power
  • 10 second average power
  • 30 second average power
  • Lap average power
  • Overall average power

Getting Started with Power Averaging

  1. Grab your Connect IQ compatible watch and sync it up with Garmin Express on the computer
  2. Install/update Stryd Power from the Garmin App Store. Click the link and hit ‘Download’. (
  3. Sync your Garmin watch with Garmin Express on the computer to install/update Stryd Power
  4. Select ‘Manage Apps’ on Garmin Express and find Stryd Power
  5. Click on the ‘…’ option next to Stryd Power to configure the options
  6. Select the ‘Power Averaging’ option and choose one of the options.
  7. Sync your watch
  8. Customize the data screens on the run mode on your watch to see Stryd Power

Stryd Power In Your Hands

We have had early success with Power Averaging at the Stryd Headquarters. We believe this is the next step to successfully pacing your race. We want to see what you can do with Stryd Power. Share your pacing success story on the Stryd Community!

Stryd is Most Accurate Device Tested by fellrnr!

GPS_Accuracy.pngGreat news to report! fellrnr of (a widely trusted source on evaluating running technology accuracy) ranked Stryd as the most accurate distance reporting device that they have tested to date. See the full report and supporting data here. Stryd is not only now ranked at the top of the industry, but Stryd’s first placing comes with quite a large margin over the rest.

Stryd’s precision (even when uncalibrated) particularly outshines the field. While maintaining high performance without calibration, Stryd has elevated the state-of-art in the run-tracking industry to a new standard. Both uncalibrated and calibrated, Stryd shows higher precision than any other device tested by fellrnr, showing consistent accuracy across day-by-day variations such as pace, run form, surface density, and others.

Mysterious Treadmill Pace?


You may have noticed that running on a treadmill feels differently when compared to running outdoors. Understanding the root cause of this difference, it turns out, may actually help improve our run training.

We’ve tested Stryd on multiple runners and across multiple treadmills, and after all our data collection and analysis we think we know why. The root cause is that your treadmill’s belt speed isn’t actually constant. More specifically, when your foot strikes the belt, the motor is loaded and the belt slows temporarily. Conversely, when your body is in the air, the motor applies an extra speed to the belt to recover from the previous loading. This extra speed is recorded by the treadmill, but it isn’t applied to you as the runner.


Notice from the figure above, that

  • the belt speed (in blue) reduces at each foot strike, and to compensate,
  • the treadmill motor temporarily over speeds the belt when the runner is in the air.

The extra distance traveled by the belt (shaded in red) while freely moving underneath the runner does not cause any extra effort or metabolic cost to the runner. Our study shows that, on commercial grade treadmills with good calibration, the “free distance” recorded by the treadmill accounts for about 2% of the overall. (Note: some laboratory grade treadmills with specially designed flywheels are more resilient to such effects, while older and less powerful treadmills are more susceptible).

Let’s ALL Be More Accurate!

Further, when performing our study, we found many treadmills which had poor calibration. This means that the treadmill displayed a speed which was not accurate compared to the measured average belt speed (notice the red line in the plot above is ~6.9, while the treadmill was set to 7.0). The good news is that all treadmills can be calibrated to an accurate speed without a professional’s help, including to compensate for the overestimated 2%. Here’s how you can do it by yourself, without any specialized tools, and in only a few minutes time.

See the entire process step-by-step, in only 50 seconds of video


Youtube Playlist: How to Calibrate your Treadmill

Measure true belt length

(Using a roll of sticky tape and a tape measure) Manually rotate the belt and place three pieces of tape at points evenly distributed across the belt. Measure the distance between the three and add them together to get true belt length.

Measure true belt speed

(Using a friend with a stopwatch app) Keep one piece of tape on the treadmill belt, and set the speed you wish to calibrate to. Have your friend watch you run, counting tape (belt) revolutions as they measure time. Stop the timer when you reach 100 revolutions.

True Belt Speed = Revolutions * True Belt Length / Time

Running Stress Score

After each day’s workout, we all wonder — how was my workout today? Have I done enough? Did I push too hard? Indeed, consistent training with the correct load and variety spurs the best physiological improvement; the secret sauce to how top runners build fitness quickly, to run faster.

This is why we designed Running Stress Score (RSS), a single number to help runners understand their day-by-day training. It quantifies how much you’ve trained and the variety of intensity in your training.

The primary input to RSS is running power, the direct measure of running intensity, along with the time spent at different training intensity levels, as follows.

RSS = 100 x training duration x (Power/CP)^K

● Critical power (CP): your maximal average sustainable power over one hour of running, also referred to as “lactate threshold” power; this is used as your performance baseline.

RSS quantifies your day-by-day running intensity relative to your critical power. This makes RSS comparable, enabling self-comparison throughout a training season, training load comparison between different workout types, as well as comparison between athletes with different abilities.

The coefficient K accounts for the fact that different intensity levels spur different physiological adaptations. In order to achieve your best potential, it is important to have the right training variety across all intensity levels, while allowing the proper recovery time for each.

Note that, RSS shares a similar form as the Training Stress Score (TSS) used in cycling. Yet, cycling and running are fundamentally different sports. In particular, run training is often constrained by mechanical stress. Increasing running intensity results in higher stress on our body than comparable increases in cycling. Indeed, the coefficient K for running RSS is significantly higher than that of cycling TSS, reflecting the higher stressing effect of intensive run workouts.

Simply put, RSS is a point system, awarding a certain number of points to each of your workouts, based on how intensely and how long you train. RSS is designed around a reference benchmark score, such that if you run for exactly one hour at your critical power, you will earn 100 RSS points. The following two tables show the RSS score for one-minute of running at different intensity zones (levels), as well as the typical RSS found in a set of common workouts and races.


Table 1. RSS per minute at different intensity zones (levels).


Table 2. Typical RSS of exemplary workouts and races (provided by Hans van Dijk and Ron van Megen).

Using RSS to better understand your training plan

Our day-by-day run workout is structured in the form of a multi-week/month training plan. RSS can help you establish a quantitative view of the training plan, understand the underlying training philosophies and strategies, as well as the specific objectives of different training phases. Such knowledge will help you improve training specificity, gain better training results, and thereby do better on race day. Next, we will provide a few examples to elaborate on the details.

How does workload progress throughout a training season? The following plot shows the weekly RSS of four widely used Marathon training plans developed by four world-known coaches. It is interesting to see that, even though the four training plans were developed by coaches with different training philosophies, they exhibit similar workload progression throughout a training season. Specifically, for all four plans, workload ramps up over the base phase with an approximate 5-10% week-by-week increase. Workload peaks about two-thirds into the training season, and the volumes all decrease sharply during the tapering phase. In addition, the training intensity zone breakdowns all follow similar patterns across all four training plans. For instance, high-intensity run training is rare during the base phase across all four training plans. Clearly, there is common consensus in terms of the basic training principles.



How do different training philosophies influence training practices? The following plot compares two of the Marathon plans developed by two world-known coaches. Hansons’ plan consists of a sequence of micro-training cycles, e.g., a three-week intensive training with one-week recovery. On the other hand, the weekly long runs in Pfitzinger’s plan are significantly longer than that of Hanson’s plan, with less volume reduction during the tapering phase. These observations show how RSS can be used to concisely describe each particular training philosophy.


How to plan a weekly workout? All four training plans also follow similar weekly workout compositions during the quality training phase, e.g., intervals and hill repeats, recovery runs, and weekend long runs. The following plot shows an exemplary weekly workout, which consists of three high-quality workouts, spread across the week, and separated by recovery runs and a resting day. All high-quality workouts show similar training workload, i.e., RSS score, but with distinct intensity composition. Again, how much you train (overall workload) and how you train (variety) are the key factors to effective training.


How does a specific type of workout progress throughout a training season? The following figure shows how the weekend long run progresses throughout a training season. During the base phase of the training season, gradually ramping up long run helps build up enough mileage to prepare your body ready for the quality training phase. During the quality training phase, long runs are essential to educate your body to burn fat, and improve your leg strength and resistance to fatigue. During the tapering phase, race-pace training helps improve your running economy while at race pace, and reducing long run mileage helps accelerate recovery, so you will feel refreshed on race day.


Analyzing your daily workout on Stryd PowerCenter

Stryd PowerCenter uses RSS to help you obtain quantitative understanding of your run training, from your day-by-day workout to seasonal training.

After each day’s workout, when you log onto Stryd PowerCenter, you will see the overall RSS score from your daily workout (top left), the training intensity zone breakdown (pie chart), along with other key workout metrics, such as pace and duration. You can compare it with your training plan to see if you’ve achieved your daily goal in terms of compliance to the workout and its intensity levels. RSS is supported by the training plans released by Stryd, including distances from 5K to Marathon.


The PowerCenter provides detailed workout analysis, showing how your RSS progresses within your daily workout. For instance, considering an interval workout, using the lap breakdown feature you can clearly quantify how your training stress accumulated session by session.


The PowerCenter also supports workout comparison. Comparing two similar workouts, e.g., two interval sessions from different weeks, can help you understand how your training and fitness level progresses.


The PowerCenter further provides a chart showing your daily, weekly and monthly RSS summaries, helping you understand how your training progresses throughout the training season.


In summary, it is our hope that RSS can shine light on and into your workouts, enabling you to customize your training workload and training variety, and therefore helping you train effectively, and ultimately, run faster.