Running with Power: Insights from Stryd's High Performance Director
April 5, 2021

Do you need to leverage power in your run training? What are the benefits of using run power compared to pace and heart rate? On today's episode, the Director of High Performance at Stryd, Evan Schwartz, joins host Andrew Harley and coach John Mayfield to discuss running with power. Evan describes how Stryd measures metrics such as pace, elevation, vertical oscillation, ground contact time, cadence, and leg stiffness. Learn how you can analyze your run form from tracking these metrics and how to leverage running with power on race day.


Intro: This is the TriDot podcast. TriDot uses your training data and genetic profile, combined with predictive analytics and artificial intelligence to optimize your training, giving you better results in less time with fewer injuries. Our podcast is here to educate, inspire, and entertain. We’ll talk all things triathlon with expert coaches and special guests. Join the conversation and let’s improve together.

Andrew: Welcome to the show, everyone. Super fun topic today. This is an episode I’ve been eager to get to for quite some time and it’s finally here. Today we will be talking about running with power. Making this conversation even more exciting are my guests joining for today’s show. First up is Evan Schwartz, who has industry leading knowledge when it comes to run power. Evan is the director of High Performance Elite Athletes and Coaches at Stryd. He also produces and hosts the Stryd Power podcast, talking all about running with power. He’s a 2:18:00 marathoner who ran collegiately at the Ohio State University. Now, Evan, to my knowledge, you are the first Ohio State Buckeye on the show. How does that feel?

Evan: I’m surprised because it seems like the Buckeye network is so vast and wide, it surprised me. But it feels great to be talking today.

Andrew: Also joining us today is Coach John Mayfield. John is a USAT Level II and Ironman U Certified Coach who leads TriDot’s athlete services, ambassador and coaching programs. He has coached hundreds of athletes ranging from first timers to Kona qualifiers and professional triathletes. John has been using TriDot since 2010 and coaching since 2012. John, you ready to talk run power?

John: Obviously I’ve been spending too much time with our friend Jeff Raines because I think this is going to be a powerful episode.

Andrew: Boooo. That’s a terrible pun.

John: That was bad.

Andrew: Although, normally, John, with the puns on this show we have the same three or four triathlon puns that keep reoccurring, but that was our first power pun. So I guess kudos to you for that. We’ll allow it today. I’m Andrew the average triathlete, voice of the people, and captain of the middle of the pack. As always we’ll roll through our warm-up question, settle in for our main set topic of running with power, and then wind things down with our cool-down. Lots of good stuff. Let’s get to it.

Warm-up intro: Time to warm up! Let’s get moving.

Andrew: Runners and triathletes are often food lovers, as well. Deep bouts of exercising and consuming calories just naturally go hand in hand. Throughout the endurance sport community several food themed events have developed over the years. There’s the famous beer mile where participants chug a beer each lap around the track, with the beer chugging time added to your overall finish time. There’s the Twinkie run where you get one minute deducted from your finish time for every Twinkie you eat on the course. Of course there are races where you consume food at the halfway point of the race, thus running the second half of the race with a tummy fully of pizza, ice cream, bacon, or Krispy Kreme donuts. John, Evan, for our warm-up question today: If you were creating a new food or beverage-themed race, what would you make athletes consume and what kind of race would it be? Evan, we’ll go to you first on this.

Evan: I’ve been spending hours each day pondering this question…

Andrew: Good. That’s what I like to hear.

Evan: The depth and the breadth of this topic is second to none. I think I’m defaulting back to making a little bit more participant-friendly, family-friendly option. I would go with a seltzer mile or seltzer 1600 if people don’t want to mark back 9 meters on the track. I’m a big seltzer fan myself and I feel like seltzer has gotten a lot more popular. There’s people in certain camps that really like certain brands. I would probably just go with a spin-off of a beer mile and go with a seltzer mile.

John: So you actually could do both. You could have the family-friendly version or the…because now we have all the other…or the beer-type seltzer ones, as well. So you could have different categories…

Evan: For sure. There are certain…maybe you could have different flavor categories, as well, for the certain people that like certain types of flavors, as well. I would go with the seltzer mile.

Andrew: I think that’s a super fun idea. It would definitely burn a little bit going down as opposed to some other things that you could chug. That carbonation would hit you hard. But, yeah, sounds like a lot of fun. John Mayfield, what are you thinking for this?

John: I also thought long and hard. Pondered it for many days. The proud Texan I am—one thing (one of many things) Texans are very proud of is our food. One of our favorites is our Tex-Mex. There’s a joke: you can go to a Tex-Mex restaurant and there will be a hundred things on the menu, but, effectively, there will be 4 ingredients. So it’s the same ingredients packaged a different way.

Andrew: Tortillas, meat, beans…

John: Meat, cheese beans….maybe some sour cream and that’s pretty much it. Whether you roll it up in a tortilla or a crispy taco shell or a bigger tortilla to make a burrito. So I think that’s part of the race. Whatever you want, you assemble your ingredients. By the end you have your Tex-Mex feast and maybe finish line you have a nice salted margarita there waiting for you to finish.

Andrew: Long-time listeners of the podcast will know that’s the most John Mayfield of answers possible for our warm-up question. John loves his Tex-Mex food. John, living in Houston you certainly have plenty of it around you. Good for you. Taking some inspiration from cuisine you already like and turning it into a race idea. I think it’s a great thought. For me, I decided to go a little diabolical with this one. I don’t know who would sign up for this, but hear me out: what if there was a chocolate milk super sprint triathlon? I’ve said it on the podcast before—I love chocolate milk after a race. Whether it’s a 5K or a triathlon, there’s just something about a nice chilled chocolate milk that hits the spot. I thought it would be fun and a little evil to incorporate that into a super sprint triathlon. The thing with a super sprint is it’s a shorter race, so no matter who you are or how athletic you are, you’re going to…just about going as hard as you can for that entire race. So if you made athletes at the beginning of the race in T1 and T2 drink a little 6 to 8 ounce serving of chocolate milk or milk, and then proceed onto the next portion of the race. Man, people would be hurting by the end. One, you’re going all out so your muscles are burning. Your lungs are on fire. Two, you’re trying to keep that milk down without just totally tossing your cookies out there on the course. I think that would be super entertaining to watch, to participate in, and that’s my pick. I’m proposing the chocolate milk super sprint triathlon.

John: I think it also would combine the old “Can you drink a gallon of milk in an hour?” kind of thing.

Andrew: I like it. Hey, we want to hear from you guys on this. We want to hear what the TriDot podcast audience has to say here. Make sure you are a member of the I Am TriDot Facebook group. There’s thousands of TriDot and triathlon athletes on there, just talking swim, bike, and run all throughout the week. Go find the post today posing this question: If you could create a new food or beverage themed race, what would it be? What would you make athletes eat or drink? What type of race would it be? We already have the suggestions of a tex-mex race, a seltzer water race, and a chocolate milk super sprint triathlon. But what is your idea? Go to the group. Go to the post and leave your response today.

Main set: On to the main set. Going in 3, 2, 1…

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Andrew: When it comes to endurance sports technology, there are slight developments and updates to the existing tech on the market each and every year. It is not very often that a new product comes in and dramatically upgrades our ability to train and race. So, when something new comes along, it deserves to be talked about with great excitement. And the release and popularization of the Stryd Running Power Meter is huge for runners, triathletes, and coaches alike. And TriDot triathlon training now incorporates run power into the run workouts athletes receive each and every week with their training plan. So, Evan, with TriDot being data driven training, our team is always looking to stay up to date with emerging tech and ways of gathering data. So naturally, TriDot founder and CEO Jeff Booher forwarded an email to me that he received on March 4, 2015, as one of the first 100 backers of Stryd on Kickstarter. Talk to us a little bit about the history of Stryd and how the company has exploded from then to where it is today.

Evan: Yeah, so I’m actually doing a little bit of research for this. I went back and ventured and looked at the original Kickstarter page from 6 years ago. Stryd originally started 2013, 2014 in Boulder, CO. A couple people at the University doing research on human movement and performance. Eventually, they got to the point where they were kind of solidifying down to things that they were interested in. Kind of branching off the overall subject of human movement and performance. Running power was one of the first really intriguing things. Doing a lot of research there, they launched a Kickstarter in 2015 as a clip that goes on the back of your shorts. It had moved around locations a little bit. It moved from a shorts clip to a chest strap to the Stryd, that most people are familiar with, in 2016, the foot pod. When you go from tracking movement from a chest strap to the foot, you actually open a lot more doors in terms of some metrics that you can look at that are relevant to runners and some other options that become available. I started at Stryd early 2018 and I can say that time difference from runners and triathletes were probably familiar seeing something getting popular on Kickstarter that’s more athletically related versus stuff that’s normally on Kickstarter and crowd funding websites. But the difference in Stryd from 2016-2018 and 2018-present is just amazing in terms of the advancement of features focused on training and helping people understand their running more. So the sort of thought was Stryd just used to be a rock solid hardware product. But over the past few years, there’s been an extreme dedication from our side to bring that software up to par and then exceed that expectation that hardware had as well. It has definitely exploded in terms of popularity and word of mouth. But also our investment from our side in trying to make a better training experience overall is the direction we’ve gone. And I’ve been so excited over the past few months for the training features that we’ve released and then looking forward to all the great things we have in the works to make training an even better, an easier thing, no matter your ability level is the thing that we’re really focused on. And the thing that gets me excited, and everybody at Stryd is an athlete or runner themselves, and that’s the thing that we get to get excited about every day is making training better for you.

Andrew: What I love about Stryd is the mission of Stryd to educate athletes, to help athletes train smarter, is very much in line with the mission of TriDot. To educate athletes, help athletes train smarter, help them race better. And so Jeff, our CEO and founder, very much expressed we are a software company, we design triathlon training, so he always has his ear to the ground on new emerging devices, new emerging tech, new emerging hardware that will help us do that even better. And so with his pledge on the Kickstarter campaign, he received 5 Stryd devices way back then and started learning about them and using them. And that brings us to where we are now where we’re encouraging our athletes to get them and to use them and to leverage this technology in their own training. So, Evan, as we talk about running with power, go ahead and hit us with the why. Why do triathletes and runners need to be leveraging power in our run training? What is the benefit compared to just using pace and heart rate?

Evan: Yeah I think there are a few interesting directions to take this. One of the first things that I can speak to as a semi-competitive athlete myself, having trained with pace or heart rate, gotten to a certain ability level, gotten used to using a thing like pace and heart rate for years, and reaching a semi-competitive level is as runners you never have to throw out a metric that you’ve been using. So one of the things that people see with Stryd and power specifically is “oh I don’t want to switch from pace and heart rate.” That sort of mindset that I had was what can I use to personally, before I started working at Stryd, what can I use to add on top of my training. And that’s the sort of question that we try to answer too. For triathletes specifically, I think that’s a lot easier question to answer compared to runners. If you’re a triathlete and you’re listening to this podcast, chances are you have some familiarity with the concept of power and why you might use that on the bike. So even though what Stryd does for running power and what people might be familiar bike power from a mechanical power aspect, the concept of monitoring your output rather than looking at how long it took you to cover a certain distance in a certain amount of time and the rate at which you covered that. Or look at the number of times on average that your heart beat in a certain section. Stuff like that. Adding power as a metric on top of that, people are already familiar with that if they’re coming from the triathlon side. For runners, it is one of those things, it is one of my favorite experiences. People might hear about Stryd, hear about the concept of power, but until you see your power spike up as you start to increase your effort going up a hill or if you see yourself, you check down at your watch as soon as you get hit by a gust of wind, like a headwind, and then you flip and immediately turn around and run with a tailwind, the experience in run of knowing that there is a number and a metric that does reflect your perceived rate of exertion and how hard your working in real time and simplifying that down to a number is an amazing experience and is very hard to comprehend for runners that are coming from just pace or heart rate without actually being in that scenario too. One of my favorite things is in the first week, two weeks, three weeks, four weeks, those key experiences that people can relate to and make them believe that this metric or number encapsulates a different feeling that pace or heart rate doesn’t just adds on top of that experience and gives them a better understanding of the running. And that’s the main thing is we add a better understanding of your running. If you are trying to qualify for a certain race that has a time standard, then you have to cover a certain distance in a certain amount of time, so pace is totally there. If you track your heart rate in a certain way where you are doing max heart rate tests and you are tracking your recovery heart rate and stuff and you use heart rate in its own way, that’s absolutely fine. But then adding another thing to give you more information and knowledge in your running, that’s where power has a benefit and you can actually leverage it in your training.

Andrew: Yeah and that’s great. Evan, our whole staff has been using these for a little while now, so we’ve gotten pretty familiar with running with power as opposed to just pace and heart rate. And I’ve found personally I just love when you’re on a run and you’ve got a certain interval where you’re supposed to run a certain pace for a certain amount of time and you come up to a hill and instead of really forcing myself to work too hard by holding that pace going up that hill, I know what my power range is and instead of worrying about pace, I just look at my power and the same power I was holding on the flat is the same power I’m supposed to be using going up the hill. And sure my pace is going to dip a little, but the intent of the interval, how hard I should be working, remains intact, rather than working too hard. And I’ll tell you Evan, where you talked about the wind, I very vividly remember my first time running with the Stryd power meter. On my watch, I could see my power output, I was running on a flat surface, and I took a left hand turn straight into a gnarly headwind. And I remember looking down at the watch and my RPE went up, I felt like I was working harder, and sure enough I was not going uphill, I was on the same flat level terrain, and looking down at that watch, my power, the amount of watts I was pushing, went up. And it was very, very easy to accommodate that wind and help me as an athlete run the correct pace, run the correct effort rather, by referencing power and the wind rather than just pace. So, super cool stuff. Excited to learn more about it in our conversation. John, as TriDot athletes, we’re used to using heart rate and pace to execute TriDot run sessions and now we’re throwing power into the mix. Tell us, which runs should still be guided by power and which should be guided by pace?

John: So, first, I really appreciate what Evan said there that these new emerging technologies…

Andrew: He’s a smart guy, Evan Schwartz.

John: They’re not a replacement. They’re an addition. It’s another arrow in the quiver. The more of those arrows we have in the quiver, the better off we are. Especially as Evan alluded to, when you’re using these properly and together and even this question is a great example of that. So, it’s not that it replaces pace and heart rate. It’s an additional improvement on that. It’s a relatively common misconception with triathletes. Power does not remove the need to track heart rate. It’s still a very viable metric that’s telling you how your body is responding to that power you’re producing. So it is certainly relevant, and in this case as well. So we have the ability to really have three powerful metrics. Power is subjective in cycling. But it is more objective in running because it’s not subjective to all the things that can interfere with it on the bike. Now we have three powerful metrics in pace, heart rate, and power that provides for a better overall training experience. So a great answer is every session is labeled, whether it should be done off pace, heart rate, or power. And it really comes down to what is the intent of the session. So, mini sessions are about building stamina or building functional threshold. Others have a focus of recovery or cardiac efficiency. So you achieve those different training adaptations by training in different ways. So those recovery sessions, those sessions where we’re looking to build cardiac efficiency are zone 2 sessions where we’re looking to achieve all those benefits of zone 2 training. So things like mitochondrial density and all those things that go along with zone 2 training, they have to be done at zone 2 heart rate. If you cross over, you exceed the threshold of zone 2, you get a training benefit, but you’re not getting the benefit of those other things. And those sessions are prescribed so those benefits can be achieved. And again these are cardiac efficiency, mitochondrial density, there’s a whole list of things that are best achieved by training at a low heart rate. That’s where things like, we’ve always said pace is not particularly relevant for that. It’s still a good idea to keep an eye on pace and now we’ve got the arrow of power on that. And as we improve these training adaptations, the proof in the pudding is now you’ll be able to hold a faster pace or higher wattage for that given heart rate. And that’s the proof that this work that you’re doing is beneficial. Oftentimes athletes really question it, they challenge it, they don’t like it, because they’re used to running a pace that’s x and now I can only run 60, 70, 80% of that. I don't like that. I want to run faster. I don’t want to run slower.

Answer: It’s gotta look good on Strava, John. It’s gotta look good.

John: So you need a little disclaimer on some of those like, hey I’m trying to improve my heart rate on this session, so don’t judge. Or do. Either way, underestimate me on race day. So it really boils down to what is the intent of the sessions and we use those metrics to guide the session accordingly.

Andrew: So the Stryd footpod itself weighs an incredibly light 8 grams. You don’t even remotely notice this thing on while you’re running.. Talk to me about what the unit is doing while we run. We don’t need a deep, engineer level breakdown or anything. But to a point where a curious athlete may want to know, how does a Stryd athlete actually work?

Evan: Yeah I think there’s a thing with the Coca-Cola recipe where the people who know the recipe are not allowed to fly on the same plane. So I’m not on the paygrade to know what all the sensors are. But essentially it is a 3D motion tracking device from a hardware side. And it has been that way since it’s been the footpod, using a combination of different sensors to track different things about your motion through 3D space. The latest thing with our update, which we call the windpod, the device that has the upgrade, to monitor your motion through air resistance is the newest, more specific thing rather than the sensors we had previously. That’s my favorite thing is learning about all of this stuff too. I had no idea when I started a couple years ago that I would be semi-versed or start to understand fluid dynamics as a non-engineer. Learning that was really, really cool. But what Stryd does is track your motion through 3D space based off of hardware and then using fantastic software algorithms relates that to showing power output, monitoring pace, great metrics like ground contact time, leg spring stiffness, vertical oscillation, measuring the grade that you’re running at. A lot of great metrics added on on top of just power.

Andrew: So, TriDot uses an athletes FTP to guide their pacing for training sessions with an athlete completing a 400 meter swim, a 20 minute bike power test, and a 5k run time trial every 4-6 weeks to update their thresholds. Stryd works really well with TriDot to determine an athlete's critical power zones for the run. Evan, can you explain critical power to us?

Evan: So when I had, I’ll take a tiny step back to explain it. When I had graduated college, I wasn’t involved in the exercise physiology side, wasn’t involved in the engineering at all. But I had a passion for learning about exercise physiology. I never thought for a job I’d be talking about critical power and threshold, but it’s so fun to learn that stuff. Critical power from a runner’s point of view, with no familiarity of power, the word power maybe scares people or seems intimidating because it’s not a term that normally gets used. When you add an engaging word “critical” right before power, it seems even more intimidating. And so I usually try and explain it in a way that people can understand or relate it to something they’re familiar with. So from our side, the definition of critical power is the point at which the dominant type of fatigue your body is experiencing changes. And so people in the running world throw out the word “tempo” or “threshold” or “LT” or “cruise intervals”. Stuff like that. There’s a lot of different words for riding a threshold and finding that point. For Stryd specifically, we expand a little bit more on the concept of critical power. You can have an FTP (functional threshold power) that’s usually time bound and people think of it as usually one hour power in work examples, typically with prescription. And that's something you can test via different methods. With critical power, you can say critical power 30 or CP 30, which is your 30 minute power. CP 45, you can use that term. For Stryd, critical power, we have done a little bit more work on our end to establish an auto calculated critical power model. Which blends 3 different types of physiological models. We have great support articles on pretty much anything on our side where we explain the full physiology, the full math behind it, the rationale and the reasoning. The auto calculated critical power model looks at all of your runs on the Stryd side and then generates that number that’s personal to you. Auto CP is what we call it. So, auto calculated critical power. It’s not a scary thing. It’s just a number that you can take certain percentages of and relate certain things off of that. So that’s what I would say critical power is.

Andrew: And once again, the cool thing here is, for an athlete, this is being done for you. Stryd is doing this in the background for you. You pull up on TriDot, TriDot is showing you what your power zone should be. You don’t have to break out a calculator and do some math to figure out what your zones should be. Just trust the training, trust the system, and trust the ranges that are given to you. So, once we know our critical power and our power zones are established, how can we use that to train properly, regardless of whether we’re at the track, a flat path, rolling hills, or challenging trail terrain?

Evan: Yeah, I think this is a super interesting question and I put one slight qualifier on it, for the Stryd side. The only thing I have good experience and can talk about is we have some default zones that are set, basic run numbers around your critical power. So your easy runs are typically up to 80% of your critical power. That moderate zone 2, like John was talking about, again zone 2 can be different depending on what training system you’re in. Between 80-90%. Threshold is 90-100%. Zone 4 100-115% and Zone 5 is 115+. For zones, I would say that the day to day stuff, whatever training system you’re using and you have confidence in in terms of zone breakdown, listen to that. Stick in that system, especially if it’s the TriDot platform and coaches giving you that advice. Use that specific thing. What you do based off of a critical power or functional threshold power, it really matters that you’re consistent with it. But the thing I would say about power in these situations, besides just power zones, is the number that you have, let’s say that my wattage for today is 240, the portability of power is the important thing. So if I want to go run (cause I’m in Boulder, CO) up to 8,000 feet, I would be going super slow, but I’d still be going 240 watts. And then if I’m coming back downhill, I might need to run a little bit faster to get 240 watts. If I’m going to the track and I have a specific pace that I’m trying to hit on the track and I know what my portability is from doing marathon sessions on the dirt roads and I’m trying to hit 320 watts, I can take that and find that on the track and be able to find my pace per km/per mile. So it’s not about the number but it’s the portability of the number that you’re able to work in from your training, or whatever your coach prescribes. That’s the important thing to be able to use power, understanding that no matter what your environment is, you don’t have to stick to a certain pace running up a very, very steep hill. You can look at that stimulus from the power side and be able to relate that in your training. And I think that’s the most important concept that people get with power and it ends up clicking after a little bit. But on the surface it seems like, well from my trail runs or my uphill runs, what power should I run?

Andrew: Yeah because power is power. 280 watts is 280 watts.

John: I like those comments of portability. I think that really speaks to it. And that’s sometimes a concept that is lost. Where athletes have a tendency to get fixed on a number, or even distance or elevation gain. But all those things, the body doesn’t perceive any of those. The body doesn’t know how fast it’s moving. It doesn’t know how far it’s gone. It doesn’t know elevation gain. All it knows is that intensity level, and that’s where that portability comes in. You mentioned your watts are your watts. Regardless of if you’re running uphill on a trail that’s really slow or running downhill on a smooth surface that’s easy to run on, if you’re training your body, you’re making adaptations through your training, what matters is the effort level that you're holding. And that’s the huge benefit of power, it’s the great, objective, portable measurement and quantification of that effort level.

Andrew: I think the most wild moment for me on any run using my Stryd Power Meter is that moment when you’re in a zone 4 interval, maybe even a zone 5 interval, and you’re running up hill at that power wattage and crest the top of the hill and start going downhill in the same interval and man, you’ve really got to get the legs spinning sometimes to keep the same power level while going downhill. It really highlights for you how much easier it is on the body to run downhill as opposed to uphill. It’s just totally wild. So, just transitioning a little bit, like it or not, most athletes will at some point find themselves knocking out a workout on a treadmill indoors. Do we connect our Stryd to our watch and run by power, just like we would outside? Or do treadmill runs kind of change the way we need to use power in that session?

Evan: Yeah, this is super interesting. We actually recorded a podcast on this last year because seasonally, typically in the northern hemisphere, people will run indoors on the treadmill more this time of the year. And we wanted to provide a little bit more information. There’s a great article by Coach Steve Palladino. He has the Palladino Power Project, which is his own coaching and training service. He writes a lot of helpful articles. One specific one is how to translate your training with power indoors to the treadmill. There are few conceptually different things. Especially after we introduced adding air resistance into the equation. When you are outdoors, you are running through space and you are overcoming air resistance in a certain way. You’re not always overcoming a head wind. If it is still air, you are overcoming the air resistance equal to the rate of speed that you are moving forward through space. If you have a tailwind, sometimes that evens out and you don’t have an extra contribution from the air resistance that you have to move through. When you go indoors on the treadmill and you’re running in place, you no longer have to overcome air resistance.

Andrew: I mean the fan blowing on your face at best.

Evan: Exactly. And there are actually, and I’m super glad you brought that up too, because there are key points to translating how you’re normally used to traveling through air resistance outside and what that power looks like. And then if you’ve typically been training outside, I can look at my Stryd app and we have this cool insights feature that will show me training temperature over the last 90 days, so I can look and see that here in Boulder, my average training temperature over the last 90 days is 36 degrees, because we had a couple zero degree days that I was outside. But I can all of a sudden go to the treadmill and it’s 70-75 degrees inside and I don’t have a fan, I need to understand how to change my power prescription. I may need to lower my power wattage a little to have an equivalent for what I have been used to. Otherwise, I’m going to suddenly be using a lot more energy to try and dissipate heat from my body if I don’t have a great fan on me. I picked up Zwifting last year and I learned quickly how hard it is to cycle indoors for 20 minutes without a fan and I went out and bought a fan after my 5th day indoors because I was just dripping everywhere.

Andrew: I’m surprised it took you 5 days.

Evan: Yeah, I mean I was an idiot. I was like, “Why can’t I push harder? I should be able to push a lot harder.”

Andrew: Like, “I’m dying. Why am I dying?”

Evan: Exactly. But the treadmill is a great training tool. It is the most equivalent thing that you can do to outside running. We have a fantastic treadmill in the Stryd office, where in normal times we would test people. We have great fans set up. But there are a few key things, understanding that you have to adjust your targets based on the fact that you’re no longer overcoming air resistance. So you may have to bump up the speed a little bit to get the right wattage. So if you’ve been used to running a certain 5k speed, you may have to run a little bit faster to have an equivalent wattage. You may have to lower that wattage if you don’t have great ventilation or lower temperature. And specifically recording, we encourage people to use the Stryd mobile app or Garmin app in indoor mode or Apple watch indoor mode. If you don’t there’s actually some really interesting things because Stryd has a barometer and if you have forced air or HVAC, the pressure changes will tell Stryd you’re going up and down mini hills.

Andrew: Wow.

Evan: It’s that sensitive to those tiny little pressure changes that we encourage people to use Stryd indoor mode. On the Apple watch app, we have a specific feature in there that says, “Hey, I’m indoors,” so your data can be as rock solid and as clear as possible.

John: That’s super cool. I was not aware of that, so I am definitely glad to know that. And those things make sense. For me, it revolutionized my treadmill running, so that’s been great. I was always a fan of training indoors. I’m probably the opposite of a lot of those northern hemisphere people. A lot of people train indoors in the winter because it’s too cold. There’s a certain point in the Texas Gulf Coast summer where it’s just too hot outside. I’m a weenie both ways. I’m indoor in the winter and in the summer.

Andrew: Yeah, John. Those days where it’s just 6 am and it’s already 97 degrees outside here in Texas, I’m sorry on those days I’m not going to get outside and do an effective training session. I’m just not.

John: Exactly.

Andrew: Well, Evan, would you believe we actually had some 0 degree weather days here recently in Texas ourselves?

Evan: I would believe it. I’ve got friends all across Texas and I was like wow, you’re getting a taste of what we normally deal with. But it seems wild with the normal times of I love running outside in Texas in February and March.

Andrew: Yep...I personally love the high 30’s, 40’s, low 50’s temperature range for running. Anything lower than the low 30’s, high 20’s, sorry it’s a no go for me. I’m in on the treadmill. Anyways, in addition to power, Stryd measures plenty of other metrics as well: pace, elevation, vertical oscillation, ground contact time, cadence, and leg stiffness being the primary metrics. For anyone new to those terms, what are they and why is it important to look at them in addition to power?

Evan: Like I had mentioned originally, Stryd was based around the waist as a shorts clip. And then it went to a chest strap and moved to the foot. Once you move to the foot, you can understand a little bit more about how the body is reacting as you’re running. So naturally when you move to the foot, you can do fairly simple things like cadence. You can say, “Oh my watch wrist accelerometer does cadence”. Sure, to a point. But when you go to the foot, that metric gets more accurate as you’re tracking from the foot.

Andrew: Yeah, that makes sense.

Evan: Other stuff, like ground contact time, you can get reasonably close if you’re going from a chest strap, a shorts clip. But when you move to the foot, you are measuring that and tracking that from the foot, you can get a little more accurate. Things like vertical oscillation. Leg spring stiffness gets a little more complicated. Essentially what leg spring stiffness does is look at the leg as a spring and measure and calculate how much force it is taking to bend the leg as a spring. The units are kilonewtons per meter. And so what that typically serves is looking at trends over time. And we’ve done that. In our mobile apps, there’s a specific analysis section where you can set different filters. Like I was talking about wanting to go to the track and take that marathon wattage and see how I’m performing at my goal marathon wattage. I can then apply a filter and say for runs that are between 320 and 330 watts, how is my leg spring stiffness trending? And I can look at that metric and understand those changes. I can also apply different factors, like if I’m running at sea level, if I’m running at altitude, what the temperature is, what shoes I’m wearing, what my actual speed is at this wattage, as well. So having these metrics and focusing super hard in on it is not the goal of what we want to provide these metrics for. We want to give a more complete understanding of your running. So, looking at more trends over time with these metrics specifically. I mentioned Coach Steve Palladino earlier. He’s got a great case study on running ground contact time, vertical oscillation, and leg spring stiffness in response to adding specific plyometrics three times a week in high school athletes. He’s got a great case study where he applied a specific set of plyometrics, was tracking these runners’ metrics after adding in the plyometrics, and then seeing how those runners responded. And so using metrics in that way might give a more complete understanding of how training stimulus is being responded to from an individual athlete. It’s not great, anytime just open up one run and go, “My ground contact time was this.” You have to apply a couple other things and understand. So if you have a typical loop that you do and you want to see at that specific distant what you’re running and see how that vertical oscillation, ground contact time (advanced metrics) how they’re trending, that’s what we encourage a bit more than just focusing super hard in on one metric for one run. Or what your leg spring stiffness was from minute 41:00-41:30 of a specific run that you can’t compare against anything else.

Andrew: So heading into this conversation, I listened to a few episodes of the Stryd Power Podcast. And, Evan, one of the ones that I listened to, you referenced that Steve Palladino study that you just mentioned and I thought it was super fascinating. I want to make sure our listeners understand this because in TriDot run sessions, athletes are prescribed plyometrics in order to warm up for that specific session. In that Steve Palladino study, he found (using run power and plyometrics) that the athletes who were using plyometric exercises were seeing improvements in their run form, in their run performance, and when they stopped doing them, those improvements began to dissipate. Wasn’t that kind of the gist of that study?

Evan: Yeah, and then the interesting thing too is part of that case study was once these high school athletes went back to their normal track practice and weren’t doing plyometrics, those metrics fell all of a sudden. Because you weren’t applying that stimulus, the body says I’m going to go back to equilibrium. And once he started applying the plyometrics again, those metrics went back to where they were. Super interesting case study and I wish we had a couple more people at Stryd to dive into the data analysis section and look at the cool trends that happen. But this should be a megaphone to any TriDot users. If you have specific plyometrics that are being prescribed…

Andrew: Do them.

Evan: Get that jump rope out and do your hops and your single leg hops.

Andrew: So, Evan, we’ve done all the training. We’ve let power be our guide for all the intervals that prepare us for race day. We’ve used the additional metrics to refine our technique. And we’re lining up for that 5k, 10k, marathon, or maybe we’re exiting T2 with Stryd on our foot at a local triathlon. Whatever finish line we’re seeking, how can we leverage running with power on race day?

Evan: This is a fantastic question because my go-to answer, and the way I feel confident about this, is that using Stryd, but also just the concept of power, race day is typically that day where you think about every single training session. So, I’m not a triathlete myself, but I do swim, bike, and run. And I can remember staring at the black line at the bottom of the pool, or dripping sweat riding a trainer, stuff like that. I can remember vividly a lot more running sessions than the other 2 disciplines, but for triathlon, specifically, the way I think power can be leveraged on race day is having complete confidence in the number that you’re going out to hit. You’ve trained at a certain percentage of your FTP or critical power, you’ve worked with a great coach, a great platform to give you great training, and you don’t have to guess when it comes to exiting T2 and you’re getting ready for that run. You don’t have to say how am I feeling? Am I going too fast? Am I going too slow? Should I pass this person? You don’t have to guess at all and that removes so many complications. As a runner who had trained for many, many years without Stryd, the feeling of standing on a starting line and being like am I sure I’m ready to go out 5:10 this first mile? Am I really ready to run that fast? This removes that guess. It’s not just the concept of Stryd. The concept of training and racing with power in general removes that guess and feeling of being unsure about your actual target. So leveraging power on race day gives you full confidence in yourself. You as an athlete are the most important thing. It’s not about a number, it’s about you. But giving you confidence is the best way you can leverage power on race day.

John: So power is actually a huge component of the race execution software app as well. Both in predicting what those splits are going to be. That is the primary metric to tell us what an athlete of a certain biometric make up running on a course of a certain elevation, distance, environment, that critical piece, solving for x, is what is the power? And when we’re able to establish that power number and say that this athlete, running on this course, holding this power, now has the algebraic equation to know what that predicted split is going to be. And then, in turn, that athlete can now go out and execute that power on that course on that day. It takes the guesswork out of what intensity I need to be running it. But also, here’s a hill. How do I adjust for this? We understand and acknowledge that it’s harder to go up that hill and easier to go down, but by how much? That’s really powerful. And especially the more undulation a course has, the more impact that’s going to have on the athlete. The longer the course, the more correlation potential. Same thing with wind, which is huge. How do you adjust for those things? It really takes the guesswork out. That’s a phrase we’ve used for years is TriDot takes the guesswork out of race day. But having power is a critical component to be able to remove the guesswork and know exactly what intensity you should be holding on race day.

Andrew: So, when I came on to TriDot as an athlete, I very clearly remember the lightbulb going off in those early training sessions and thinking to myself, “How in the world did I train for triathlon without TriDot?” The training just made that much of a difference for me that early on. So, Evan, for you, take me back to your first days, weeks, months, or maybe that first training cycle and that first race you had using Stryd. What was your impression and what difference did Stryd make for you as an athlete?

Evan: I love this question because I have a very vivid memory of my first race with Stryd. I made a mistake that I feel like I could educate other people on and I will never race without looking at power again. In late 2017, I ran a marathon called the California International Marathon. It has a lot of great performances. It’s a very nice course in Sacramento, CA. So I ran pretty quick there in 2017. Later that year, or in 2018, moved to Boulder, started working for Stryd, did my first training at altitude, went back to CIM in 2018 for the first race with Stryd on my foot. I decided I wanted to go off of intrinsic feel and look at the power data after. I had done all my training based on power, but I wanted to see how my perceived exertion was on an actual race course. And I get through mile 16, mile 18 the wheels fall off. I ended up finishing a couple minutes slower than I did the year before because I went out a bit aggressive. I didn’t know how aggressive it was until I looked at the data afterwards. CIM is a net downhill, about 300 feet drop over the course of 26 miles. Well within the amount of allowable drop. But what they don’t tell you is even though it’s a net downhill, there are a bunch of tiny little roll ups. So we’ve talked about maintaining that power when you’re running uphill, but it’s so easy to let that power spike. I was sticking with a pack that was running a certain pace and I looked at my data afterward and I had so many spikes above my critical power. And again, critical power is the power at which the dominant type of fatigue changes. Even if I was just looking at my FTP, I had minute long spikes, 20-30 seconds of running up these hills running 5k power in the early stages of a marathon. And because I was going off of intrinsic feel, trying to keep up with other athletes in the pack trying to run a certain goal time, I threw out my power plan I had been training with for months and ruined my race. I hit the wall at mile 18 and had to slog in the last 8 miles of a marathon, as I’m sure a lot of people listening have probably experienced before. But my first race memory with Stryd is I didn’t stick to the power plan I had trained off of, I went out way too hard, hit the hills way too hard, all because I tried to stick with a predetermined pace. That ended up biting me in the butt and I had a not as good performance. And that gave me the confidence to stick with racing with power, even if the other people in the pack are surging up a hill to maintain pace. Or if their heart rate hasn't hit that hill yet and then they crest the hill and their heart rate shoots up to 190 beats per minute and they have to basically walk down the downhill to get their heart rate to go back down. But the first experience I had was I raced poorly because I didn’t stick to my power plan. So a negative experience is definitely the most positive going forward for me. I highly encourage people to actually listen to their coach, a great training platform, and stick to that power goal on race day, which is the most important day of the cycle. You run hundreds of miles during a training cycle…

Andrew: Just for race day.

Evan: Just to have a couple miles of mistakes to ruin that experience, you never want to have that. So let my tale be a cautionary tale to actually run by power.

John: It illustrates the importance of run execution or race day execution. So many times you work for months and you have that one opportunity on race day. A few bad decisions or a few miscues and it can cost you. It’s like you said, your time that day was not representative of your ability on that day. Your time was a reflection of the execution. So there’s something to sticking with those packs, especially when you’re racing up there in the front. But backing off and catching them a mile or two later when they’re making those recovery efforts, you’re right there with them because you held that steady power.

Andrew: Evan, I’ve never run a marathon. I’ve never had the desire to run a marathon. I think marathoners are crazy. Evan, kindly, I think you are crazy.

Evan: I think so too.

Andrew: It’s just a long distance. It’s a long race. I haven’t personally wanted to do one. But my first marathon will be when I finally get to race Ironman Texas. I’m just going to go for a casual swim and bike first. I’ve heard so many stories about hitting the wall between miles 18-23. I’ve heard marathoners talking about it. I know I’m going to enter that first marathon with fear and trembling and that will cause me to stick to the plan and hit my target power and not overdo anything. Between that sense of fear and trembling and you sharing that experience, thank you for reinforcing that strategy to stick to the plan and doing what TriDot tells me and holding my power.

John: I had that thought when he said mile 18 I hit the wall and then I had to run 8 more miles. I was like, “Man, you already ran 18 and you’ve got 8 more? 8 miles is a long way to run!”

Andrew: Yeah

Evan: 8 miles at the end feels a lot longer than any 8 mile run that you’ve ever done in your life.

John: Right. Marathons, they’re interesting. You hit the wall at 18, you’re toast, you’re done. And then you still have to do another 8 miles. Another long run on top of your long run.

Andrew: Yeah, you overcook the early stages of a 5k, you just have to limp through the last half mile at the end. It’s a little bit different when you’re doing a marathon. John, for you, you’ve been using Stryd now for your own run sessions and many of your athletes now have a Stryd foot pod on during their training. What difference have you seen for you and your athletes?

John: It’s a little different for everyone given their training environments, their training equipment. For me, I live on the Texas Gulf Coast. So adjusting for inclines and declines isn’t really an issue I have to deal with. I know you live in a relatively hilly area. So this is something that impacts you on every single run session that you do outdoors. In that regard, we use it in a different way. Now, one of my favorite features is the addition of the wind feature, which is relatively new to the newer models of the Stryd pod. Again, I’m on the coast and the wind can actually impact my effort levels. It’s generally a pretty good wind. Your 2-3 mile an hour wind isn’t really going to do anything to you. But there are some days with a 10, 15, 18 mile an hour wind and you’re trying to hold a threshold pace. One way on the track is a hell of a lot easier than the other way. It’s almost that same experience we mentioned earlier. My body doesn’t know what pace I’m working. It doesn’t know if I have a head wind or a tail wind. My body just knows how hard I’m working. Same thing with you. When you’re going up and down those hills around your neighborhood, your body doesn’t know you’re going up and down. It just knows you’re working harder or easier depending on what the grade of the road is. Then another huge thing for me was the treadmill accuracy. Whereas I always had confidence in those zone 2 sessions where I was using heart rate, I didn't really care what number mile per hour the treadmill said. It was irrelevant. I was watching my heart rate. But it became a real challenge to quantify my intensity level for higher intensity stuff. When heart rate is a delayed response...I’m halfway into an interval before I really have any confirmation. Did I overcook? Did I undercook? You may not even know until you’re halfway or more through the interval set. So, the ability to come in and really have high quality metrics to use for those higher intensity sessions have been a game changer for me. And I have seen a tight correlation both from what I see on the road, as far as my power number, pace, and heart rate. I have a high level of confidence in that because I see my heart rate, power, and pace all correlate. Because I can now get that metric from Stryd. I run in a gym, so the treadmill has probably never been calibrated since the day it was new. There’s no telling how many hours that thing logs every week. So, it’s not fair to rely on that to be...it’s not in a lab where it’s being taken care of and calibrated. It’s in a gym. But for me personally, that’s probably my favorite aspect of having the Stryd is now I can Zwift on the bike and on the run.

Andrew: Yeah and we will have to be sure to go follow Evan on Zwift so that we can cheer him on, whether he’s biking or running on there.

Evan: Don’t look at my Zwift power though. I haven’t been racing a lot this year. But I’m looking forward to getting back at it.

Andrew: Evan, plenty of TriDot athletes already have a Stryd and are using it in their training. I know from our I AM TriDot Facebook group that Stryd was one of the top Christmas wishlist items for many of our athletes. For any of our athletes wanting to know more about running with power, what other resources would you point them to?

Evan: There are a few different types of resources. From the technical side, support@Stryd.com or Stryd.com/support has a ton of articles, no matter your curiosity. Whether you want to know about physiological modeling, what battery life is like, what operating temperature is like. There’s endless support articles. Our YouTube channel has a lot of great webinars, talking about different coaches and different people incorporating Stryd into their training. That’s great, if that’s your preferred method of consumption. Like you mentioned previously, we have a podcast. If you want to listen to some different types of media formats, we have a podcast or our Stryd community on Facebook has 17,000 people in it. That is there mainly for people to ask questions and share training and race experiences too. I would probably point people toward Stryd.com, which has all of those resources in different locations. And if you have any specific questions, support@Stryd.com is our fantastic customer service team. I love our customer service team so much. They answer any specific questions that you might not find anywhere else.

Cool down theme: Great set everyone! Let’s cool down.

Andrew: Evan, you have provided so much information today and really coached us on why to run with power and how to run with power. And after dropping all that knowledge from your head, I feel like we would be missing out if we didn’t hear a little bit from your heart. Cheesy line, but I mean it. To cool down our main set and wrap up our set for the day, I’d like you to take a moment to share from your successful and speedy race career, what are one or two of your favorite race day stories to tell?

Evan: Sure. I have two that come to my mind for two different reasons. The first one is probably my best race performance ever. It was at that 2017 California International Marathon. I had averaged 120 miles per week for 2 years, gotten up to blocks of 140-150 miles per week, done really long training efforts, like 20 mile efforts at 5:28/mile pace. Done a lot of crazy marathon training. And I went out with, pre Stryd, the Olympic Trials Qualifying pack that was trying to run under 2:19. I ran 2:18:19 in my second marathon ever. I had improved from my 2:31 a couple years before after training very hard…

Andrew: Yeah that’s a huge jump from 2:31-2:18. That’s great.

Evan: Pretty big jump. I think it was the fact that I just didn’t hit the wall until mile 22. So I didn’t have to suffer as long and run that last 8 miles really in a grueling situation. But that’s the most meaningful just because that’s an accomplishment that a lot of people, specifically in the distance running world, point towards. And if you qualify for the Olympic Trials, you’re probably in the top 100-250 runners in the U.S., which is a big deal for a lot of people that continue their craziness post-collegiately. So that was probably my most meaningful. The race I’m most proud of is there’s a really small, local 5 miler in northeast Ohio called the Johnnycake Jog. It is a very fast race, because there are a lot of people who come from Pennsylvania, Ohio, Michigan, Indiana, Illinois to race this because the course is pretty good. I had run it the year previous and finished 3rd. I ran, I want to say, 24:50 for 5 miles, which was a PR at the time. But then I came back, 2017 as well, and I had been racing a couple people in the local race series. I threw off my watch, and I wasn’t looking at anything rather than just racing. I stuck with two Kenyan athletes who were training in Ohio at the time. I had ever beaten them in a race before. I had always gotten walloped super hard in any race I had gone up against them with. But I just decided I was going to run with them the whole time. So, we ended up getting to mile 4, I find myself inching into the lead, and I just put my head down and ran the hardest I possibly could for the last mile. And I ran 24:11 for 5 miles, which is around 4:50/mile, which was a 40 second PR over 5 miles. It was not looking at time or anything like that. Literally just sticking your nose and hoping you don’t falter on that day. So I am most proud of that race for a different mindset. That was a couple months before qualifying for the Olympic Trials and that was the big change of going for something and believing in yourself on race day. And then I just had a good performance because I believed in myself and believed in the training I had done. That’s definitely my most meaningful and my proudest race moments.

Andrew: John, what would you do if you ran one mile at a 4:50 pace?

John: I never have. It’s been a long, long time, probably like junior high, since I actually ran a one mile time trial. But I don’t want to find out.

Evan: Sounds like that’s something you could put on the calendar.

John: Maybe.

Andrew: Well, that’s it for today. I want to thank Evan Schwartz from Stryd and TriDot Coach John Mayfield for talking to us about running with power. Head to Stryd.com for more information on run power and to get a Stryd power meter on your foot to get all this fresh data into your training. Enjoying the podcast? Have any questions or topics you want to hear us talk about? Head to TriDot.com/podcast and click on “Submit Feedback” to let us know what you’re thinking. We’ll have a new show coming your way soon. Until then, happy training.

Outro: Thanks for joining us. Make sure to subscribe and share the TriDot podcast with your triathlon crew. For more great tri content and community, connect with us on Facebook, YouTube, and Instagram. Ready to optimize your training? Head to TriDot.com and start your free trial today! TriDot – the obvious and automatic choice for triathlon training.

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