Establishing Power Zones

[@Stryd]

We love seeing the power content!

[@uscfroadie]

I love seeing manufacturer reps/employees tuning in and responding to content. Ordering my Stryd as soon as I’m done typing this reply.

[@Sbzkxos]

@@fantasytraveller Stryd is a very fun and helpful device to use. Helped pace me to a sub 16 minute 5k, over a 30 second PR. Never going back to running by pace. If you don't believe it, just move on, it doesn't work for everyone's training style.

[@Sbzkxos]

@@fantasytraveller How is it not accurate? Are you talking about distance and pace because I have tested mine on the track and it is consistently far superior to gps and very spot on. Or are you saying the power isn't accurate? If so, idk if I believe that at all because the power always correlates with my perceived effort

[@Sbzkxos]

@@fantasytraveller And where is your proof for that? The power is accurate time and time again and after 3 months of training my just the power zones, I dropped my 5k pr by over 30 seconds and went sub 16 minutes.

[@fawazghali]

@@Sbzkxos You could simply use pace zones. Nothing more, nothing less. For pacing, you can use Garmin PacePro. You do notice Stryd uses paces to determine power or not?

[@paulcain1285]

I’ve been using Stryd since I was out injured. It’s been motivating as the predicted 5,10 and half marathon times are now back close to my PB’s. Spookily my weight is also 140 lbs and my CP is currently 249 and 3.96 W/kg. But I like the way it gives me evidence as to how I feel my training is progressing. Interesting video.

[@paulcain1285]

aba bab Kofuzi is a dude that runs a lot and we all enjoy discussing running 🏃‍♂️. If that’s not your thing, then great go start your own conspiracy You Tube channel and I’m sure you’ll have 50k subscribers very soon. Good luck 😉

[@wdwebb]

Love these series of videos (Pace vs. HR vs. Power). It is always something that I struggle with - what should I pay attention to for my training/runs. To me HR & Power are very similar and good for when I am training in the off season and trying to build my aerobic engine by running mostly at a low intensity. Because I tend to focus on MAF for the off season I use HR. But when I am in Marathon training with a focus on a time/pace goal I switch to mostly pace based training (Hansons) . I find the contrast between these two training approaches very motivating for me and give me something to look forward to as the seasons change.

[@Moneyalmenial]

I'm with you all the way on those. Base building mostly driven by heart rate with a few strides and transition into a daniels style pace plan for the quality days but easy running by feel and HR. I do have the latest version of the Stryd and I kind of use the power number a bit ad hoc as a fourth variable. My Garmin 235 can't program by power so that'd make it a bit of a pain. This off season I'll probably use the auto CP as a bit of a loose time trial to gauge progress.

[@tonyrabone4668]

Really clear. Good approach. On Garmin power, I set top of zone 3 as Threshold power (power at threshold pace on flat terrain). Then garmin sets 110% TP for zone 4, 90% TP for zone 3, 80% TP for zone 2 etc. On reflection I probably cherry picked an aspirational threshold power as you say so I'm probably running a bit hot.

[@harryfranks6543]

I just got my stryd based on your video of a few days ago. Just got my first critical power number (after 3 runs). Looking forward to getting more data. Keep combining MAF and power. They make a good combination.

[@kofuzi]

I think when you look at HR and power at the same time, it provides somewhat of an efficiency rating. I’m not sure how useful it is during a run, but an interesting metric to look at to track progress at a broader level

[@brunocassettari]

You only need a couple of specific runs to set your Critical Power with Stryd, or do a CP test so no need at all to wait 90days for accurate and personal CP to be identified/set. Ideally you should have a 1-3min max effort run and 20-40min max effort (also a 10-15min max helps to improve accuracy). Stryd has great video tutorials explaining these things on their youtube channel.

[@fawazghali]

Or just use pace zones :D

[@tmantony5660]

Thanks for explaining.Up until today I knew what it meant but you have cleared the air.

[@romantrochanowski6107]

Polar's 6min test is calculating your Maximum Aerobic Speed (MAS) which is not the same concept as Stryd's Critical Power, hence the different tests. Stryd's Critical Power is an approximation of your Lactate Threshold as stated by Stryd in one of their KZbin videos. When you do the Polar 6min test, your MAS is then translated to MAP (Maximum Aerobic Power) in a 1:1 ratio on Polar's scale.Your lactate threshold speed is less than your Maximum Aerobic Speed. If you look at your Stryd Power Curve, your MAP per Stry'd values will be in the range of 5-7mins on Stryd's Power Graph as MAS/MAP is a speed/power value that you can maintain for 5-7mins.

[@garysailors]

Cool thanks! Always interested in doing more by Power

[@christianschobinger1131]

I train with the grit x, so your thoughts on that are very interesting! Thx

[@steevie76]

Disclaimer: "I'm just a dude that runs alot."

[@kofuzi]

No more. No less.

[@imp4573]

Someone should do a study comparing the power measurements from a Stryd footpod compared to the measurements from a treadmill with a force plate/ force pad and see how accurate it is

[@TheSloanlogic]

LOL. Power is more than just force..

[@ndk4]

Michael, maybe its time for your running form’s analysis video. That would be awesome! 😎

[@kofuzi]

it could be very useful. perhaps i can get my wife to video record me from a bike

[@ndk4]

kofuzi yeah it might help with your injury issues too. You will never know whats wrong until you record them, full size

[@TheSloanlogic]

Just some clarity here. Power is output. Heart rate is input. CP/FTP is relative to environmental conditions (heat/humidity/altitude). Training targets are relative to CP.. Comparing power across runners is relative to the Styrd weight setting (W/kg). *Steve Palladino.

[@seanmarshall5569]

Do you find that Stryd Power ratings help you monitor training fatigue? It seems that if your power remains but your pace slips, or vise versa, you will see that you are due for a rest day, or even foresee injury. Just curious on your thoughts here, as this seems most beneficial to me.

[@kofuzi]

I haven’t used it that way. I’m not sure. I do use HR that way though. HR is very useful for that.

[@TheSloanlogic]

100% The metrics from powercenter are better than anything out there. Your RSB (Running Stress Balance) is one of the amazing metrics you can use to see how you are doing relative to your own fitness.

[@imp4573]

Interesting that gap between Easy - Threshold from 199 - 224: what do they call that? Odd that it isn't termed

[@allencarney2918]

Have you verified consistency on pace/distance with Stryd? I have a regular simple course that's about 7.5 miles. Stryd will get usually 7.47 and once 7.1 (with no drop in connection). I've also had it jump in power for no reason on a run by 30points. This weekend on a steady flat 10mi I was at 260's watts and last 2 miles jumped to 290's with no change in effort or terrain. I've also found a consistent 10% difference running up a 1/2 steep incline and running down it. Stryd never can answer this and usually point to different shoes give different results. It's a great product for data, I just feel it's not as accurate as they claim given inconsistencies for me.

[@alessiosteccanella4441]

Hello from Italy,i like very much your Channel,i would like to know When you make a review of polar Grit x

[@kofuzi]

kzbin.info/www/bejne/eXTde2Vres-dqdk

[@amateurdeshoes902]

Do your Power with stryd on easy day reflect your HR and speed range on easy day before you start using stryd or it was different??

[@af59-photografika]

If you enter the data Zones into the Polar Grit X watch, which has been generated by the Stryd software, will that not generate ‘false’ feedback whilst you are running as the Grit X Power software has different tolerances? Or does the power shown on the watch face from the Stryd foot bypass Polar’s power algorithm until the run is saved ?

[@kofuzi]

My understanding is that, when stryd is connected, polar shows stryd data only. I think the power data field is populated directly by stryd. I’m not sure what you mean by bypassing the algorithm.

[@af59-photografika]

kofuzi - Hi, The algorithm I was referencing was the one being used by Polar. When a run is saved by Stryd and Polar, they use the run’s data differently to formulate two different Critical Power numbers, as there isn’t a universal algorithm for measuring running Power. (Garmin now have their own Power algorithm within their software also.) Stryd have created a data field app for Garmin and Apple watches, therefore only using their metrics. Stryd is unable to create one for Polar at this time. That really was my concern, If the data on the watch is directly from the pod and not being ‘Polar adjusted’, then you are getting true Stryd run info. Phew !!😀😀

[@andy1shi]

But if both devices measures power they have to give more or less the same results from a physical point of view? Becouse power is related to your velocity. Knowing your power zones may allow you to establish your pace zones in a flat surface. I know that also garmin hrm measures power and gives different power results. This is very strange? Which is correct than???

[@Moneyalmenial]

I don't think it's a "real" power number. It's consistent within it's proprietary algorithm. Almost better to call it an "energy/metabolic load" factored by incline, temp, humidity, weight, pace, height (wind resistance surface area), wind.. It all comes down to what physiological adaptations at a given intensity you're trying to illicit. FWIW, I do own one and generally believe in its validity

[@Running4Fitness]

Hi Mike...a question: Any correlation between the power zones and heart rate zones?

[@Ophio117]

Hello, I'm going to necro this old comment for the benefit of the community here and passersby. Typically, yes there is a correlation, but if training is working it should be temporary. A coach who knows what they are looking at will look at both data sets to determine various things about their athlete. For instance, if power is the same across the same workout a few weeks apart, yet the heart rate is significantly higher on the second effort, it could indicate various things about diet, lifestyle, maybe the training is too much or poorly designed, maybe it's much hotter during the second effort, maybe the athlete made some errors in hydration, sleep, or nutrition, etc. On the other hand, if power is the same and heart rate is lower, it could be an improvement in those secondary factors, but hopefully it means that more power is being produced at a lower heart rate and the training program is working. More power at the same effort (sort of measured by heart rate) is what we're going for, over time, but there can be various impediments that pop up. Heart rate vs power is a great metric for coaches to look at, and I think for the athlete, just focusing on power during the workout and ignoring heart rate is a good position to have in 2022, especially with the apple watch OS updating to produce a power number soon, there will probably be another injection of buzz around running power.

[@franklehouillier8865]

How does the stryd figure out the threshold range without access to your heart rate or other cardiopulmonary metric?

[@brunocassettari]

There are several studies that proof a direct correlation of running power and VO2max and all related cardio/aerobic variables. Check Palladino Power Project group on FB, which has a lot if great materials and discussions in this topic. I’ve been using Stryd now for almost a year and can only recommend it, but you gotta dive into the data analysis it provides to extract the most benefit it has to offer. I hope that helps. Let me know if I can help with any other questions.

[@franklehouillier8865]

@@brunocassettari I can see that max power (or average power at some point) during a lab protocol might correspond to VO2max but unless stryd is actually making sure that you go through some sort of protocol I don't see how there is any way for it to "learn" what that might be. I could easily run for 90 days without getting anywhere near my VO2max and my neighbor might be hitting it consistently every day. I guess that is true of heart rate too but at least with heart rate there are something like protocols (like the hill thing Ko was talking about last time) to actually get close to approximating Max HR. I'm very dubious of the watches that are claiming to learn VO2max from HR data as well. The claim about "all related cardio/aerobic variables" is particularly weak since there isn't even a good correlation between Max HR and V02max.

[@brunocassettari]

Frank LeHouillier you are absolutely correct. Sorry that I misunderstood your first question. I actually just posted to Kofuzi that the 90days is not needed and indeed if you don’t do max efforts Stryd won’t give you the right CP and threfore zones. There is a few protocols that can be used. For the automated Stryd calculation the recommend 1-3min max effort and 20-40min max. That will guve data fir a curve that they use algorithms on to extrapolate your CP and max. Also a true 5-6min max effort should give you a Power at VO2max and you can manually calculate other zones based on that. But indeed there are some protocols. 90days assumes that most runners will do some sort of max effort trainings enough to populate the curve.

[@brunocassettari]

Frank LeHouillier and by the way temperature/humidity/altitude will also interfere on the result, same as HR or VO2max. You need to keep the max efforts relevant to the training conditions, otherwise they the zones will not be properly set.

[@kofuzi]

Stryd creates a power duration curve after sampling from a variety of types of runs that you do. And it prefers that you do a variety of intensities on a regular basis (which I usually don’t do) for a more accurate curve. These activities plot out a power duration curve, with certain areas underneath corresponding to different types of aerobic vs an aerobic activity. There is, in theory, an inflection point at a certain point in the graph that corresponds to your threshold. I think that’s how it finds that critical power (or threshold) number. That all being said, my stryd is able to pull gps and Hr data from my watch and hr monitor. But I am not aware of how much the HR data goes into the calculation.

[@omarsalgado461]

Kofuzi, have been running with low HR for about 6 months and appreciate your info on Stryd/power. Currently run with Apple Watch, earbuds and external HR monitor. My Dilemma is trying to add Stryd with only two Bluetooth connections available. Lol.

[@edgar1105]

Omar Salgado , I run using AW S3 + HRM TickrX+ Aftershocks+Stryd. 3 connections on AW Bluetooth. Hope that helps

[@trevorcross7751]

Thanks

[@lania3717]

Hi. I have a stryd foot pod, been using it for 4 months. I'm training for a marathon. In it's beta race predictor, stryd say I should be able to run my marathon in zone 3 threshold low side of the range. Compared to you, yours would be 224. I don't think that's achievable with my abilities. I'm guessing stryd predicts everyone should be able to run their marathon at zone 3 threshold lower side of the range. Do you think the race predictor is accurate? I thought threshold zone was for 10k or half marathon races. Do you think you could run at 224 watts for a marathon?

[@JustinWarren1980]

So the power number does depend on the your body weight. So 224 for you is going to be different for others. There is some good info on the stryd KZbin channel as well

[@lania3717]

@@JustinWarren1980 I understand that power is personalized to each person. Kofuzi's threshold power range is 224-249. Mine is different. Without giving out my numbers, Stryd's beta race predictor say I could run a marathon in X time using Y watts, Y being the low end of my threshold zone 3. Running a marathon at threshold seems really hard since threshold is supposed to be a pace someone can run only about an hour at most. No one has run a marathon in an hour. My question to kofuzi is does he think he can run a marathon in 224 watts (Stryd's low end threshold zone 3), the number kofuzi displayed in his video. I'm questioning the accuracy of Stryd's race predictor.

[@JustinWarren1980]

Lani A oh, I see. Sorry about that. Just checked mine. My says high end of zone 2, or 87% of CP.

[@lania3717]

@@JustinWarren1980 ok. High end of zone 2 or 87% of CP makes more sense to me. Thank you for responding.

[@mitchellatkins9701]

Nah, not interested in power, too much info as it is with just heartbeat and pace. How's your knee?

[@fawazghali]

Or just use pace zones :D