Quick question for the Stryd users if you also use TrainingPeaks. Do you follow/ use Stryd's RSS (running stress score) or TP's TSS? I've historically ignored the Stryd RSS figure in lieu of TSS.
I did a 85-min run yesterday and for example, my RSS was 92 and my TSS for the run was 157. Given I use TP for all swim, bike, run, I can't say I'd ever concern myself with RSS.
@Jeff Phillips I use tss, but I also do not see so much difference between the two.
It seems like something is askew with your zone settings in TrainingPeaks if it gave you 157 TSS for 1:25 of running. 1 hour of running at threshold would give you 100 TSS. 157 TSS from 1:25 implies that your ran at an IF of 105%.
Check if you have run power threshold set to your Critical Power from Stryd... that should make the numbers a lot closer.
I've been following along with fascination. Thanks to everyone that's contributed so far. @Rich Stanbaugh I'm still not sure I follow the logic of not changing weight in Stryd as your weight changes. To use your example, if I ran ran the same course in the same time on two different occasions, but on the second occasion I was 2 Kg lighter, then by definition I was putting out less power the second time. If I was 2 Kg lighter the second time and I put out the same power as the first run, I would expect to run a faster time. So while the conclusion of the hypothetical example seems inconvenient (having to constantly change zones as weight changes), logically it seems correct to me. Otherwise, Stryd is assuming that you're accelerating more or less mass than you actually are.
What would be nice is if Stryd could import data from the Healthmate app (Withings scales) the same way that Zwift does. I make it a point to get on the scale 3-4 times per week, so my weight in Zwift is alway pretty accurate.
On a personal note, I ran the Santa Cruz half marathon yesterday, and decided I'd use this as an experiment in pacing solely with power and RPE. I set my Garmin 935 to have a screen with a single field: 3 sec. power. No HR, no pace, no time... nada. Focus on what I can control in the moment. Stryd Powercenter had my CP at 254 and their guidance is to pace a HM at ~95% of CP, so my goal was to run the first 6 miles at 240-245W and then see if I could bump it up slightly from there.
Miles 1 - 6 (avg. Watts): 235, 243, 245, 245, 247, 242 (mile 6 was a narrow path and I got stuck in a crowd).
Miles, 7 - 13: 254, 247, 262, 258, 263, 263, 269
Looking at the file post-race, HR stayed pretty flat through mile 9, at which point it started drifting upward to a max of 185 in the final mile. Had I looked down in mile 13 and seen an HR in the mid-180's I suspect I might have subconsciously eased up a tad. Who knows.
In the end I hit all three of my goals for the day:
(1) I established a new current CP as I transition from OS to HIM plan (new CP is now 262 Watts)
(2) I beat my time goal by several minutes (Vaporfly 4% assisted 😀)
(3) I negative split the race. Not sure it's necessarily the fastest way to run a race, as it involves intentionally holding back for 1/2 the race but it's very satisfying to be ramping up the pace as everyone around you starts to fall apart.
Great race @John Katsoudas! I paced an open half marathon last year and the run leg of a HIM solely on power due to the rolling nature of both courses. It works!
@Rich Stanbaugh Thanks for your note. I went into TP and saw I had two speed settings selected -- a pace for "Default Speed/ Pace" and also a a different value for "Run Speed/ Pace".
@John Katsoudas I understand the confusion. The bottom line is that Weight changes overnight... FTP / CP does not change over night.
We are using power meters (whether bike or Stryd) to give us guidance about our metabolism (eg FTP / VO2) to help us plan and execute training and races.
The power numbers that we see are a visible number that reflects our level of output and this number has meaning to us relative to what we understand out thresholds to be.
The confusion comes because:
Stryd doesn't measure power, it measures acceleration and then derives power, and
We are all hyper vigilant Type A personalities that believe that every number matters.
The reality is that Stryd measures acceleration and computes force from mass * acceleration (versus a bicycle power meters measure force directly based on how hard you press the pedals). In order for us to interpret the Stryd power numbers the way that we have become accustomed to with bike power numbers, we need to hold the weight constant so that we can observe changes in power that relate to changes in fitness.
From what I have read, the guidance is generally to set your weight for something in the middle of race weight / early season weight and leave it. If it is necessary to change your weight setting, this should be done prior to beginning a training block.
Changing your Stryd weight do not do anything to enhance your training, your fitness or your insights into your training / fitness.
@Rich Stanbaugh I guess I'm still not following. These two statements seem to me to be at odds with each other:
1) Stryd doesn't measure power, it measures acceleration and then derives power,
and
2) we need to hold the weight constant so that we can observe changes in power that relate to changes in fitness
If what Stryd is reporting as "power" is a derivation of mass*acceleration, and you feed it incorrect information about mass, then you will get incorrect information about derived power. You won't be able to observe changes in fitness using this data, since you won't know if the observed change in derived power is a result of changes in your body weight or your fitness (or both).
@John Katsoudas Congrats on a great race with power. Pretty interesting that you went with 3 second power only. I find that jumps around quite a bit for me, especially if I zone out for a period of time. I have the Stryd Zones Garmin Connect IQ which allows you to pick between real time, 3 second averaging, 10 second averaging, 30 second averaging, lap power, and overall power display options. I have mine showing 3 second and lap power. I tend to watch lap power most. Every mile lap then shows lap pace and lap time, which I tend to ignore.
Your strategy of negative splitting the race is probably better than mine, which is go out strong and hold on for as long as I can!
@John Katsoudas you are on the right track - just need to look at the other variable. Acceleration.
Changes in fitness, eg, ftp, correlate well with changes in the acceleration that Stryd measures. They do not correlate well with changes in weight (ie, I can lose 5# and be faster, but that doesn't relate to a change in ftp).
The underlying question here is "how do we extract meaningful information from these devices?"
Weight change is meaningful - but it is not meaningful to predict changes in ftp. Weight change is meaningful when predicting how fast we can climb a hill, but it is not meaningful when estimating changes in VO2.
If we want to estimate accurately the number of watts you produce during a run, having an accurate weight setting is meaningful. However, if we are trying to measure how much your fitness has changed over the last weeks of training, weight change does not help predict that.
This was a confusing topic for me the first time through it too. Instinctively, I am that Type A personality that things more is better.
The key is that we are using the Stryd to measure changes in fitness and to drive our training. Changing the weight setting shifts all of our existing data (CP, zones, power at certain paces, etc) so that there isn't a straight-forward way to interpret it.
A practical example of this - over the course of an IM build, I develop a feel for the watts I can run off the bike (which power I should run the first 10', what my steady run target will be, etc.) and also what HR or pace that I can expect for certain powers on flat ground. This is all helpful during a race, because it gives me context to understand / interpret what is going on at the moment.
If I changed my Stryd Weight each time I weighed myself, I wouldn't have any of that context. Last week, maybe my ROB (run off bike) power was 250w. This week I lose 5# so my ROB target is 240w. next week I am back up 2#... it goes on and on. The numbers keep changing because weight is changing - but this is creating noise. My fitness hasn't changed in concert with the number changes. The reason we are using the device is related to our fitness / ability to perform.
The general consensus on this in the Stryd forums / Palladino forum is to set the weight at a mid-plan weight and leave it. If you feel the need to change it, change it before a build or at some point in time where the auto-cp function has plenty of time (weeks of runs) to recalculate a new cp.
I love losing weight. I know it will make me faster. I keep a chart that shows me how much I have lost (and don't chart when I gain!!!). Weight chart for weight - FTP/CP chart for FTP/CP... two different things.
If you disagree - then change your weight daily... are we in the same age group?? 😁
@Rich Stanbaugh I completely agree with what you're saying about using devices (any devices) for the big-picture purpose of measuring changes in fitness. Not to belabor the point, but where I'm getting hung up is in the process of arriving at a meaningful power number that accurately represents the work being done so that we can understand if fitness is actually changing.
As you mentioned, Stryd measures acceleration, and then calculates power from that. Physics dictates that for an equivalent force a lighter mass will accelerate more than a heavier mass. In plain English, if your power stays constant but you lose weight, Stryd will directly measure this as an increase in acceleration. If you tell Stryd that you lost weight, it will say "aha! I see that acceleration is higher, but this is because the weight is lower, so I will normalize this out and report the same amount of power." If, on the other hand, you leave your weight in Stryd constant, it will see the higher acceleration, and incorrectly interpret that as a higher power because it believes your weight stayed constant. So, while well-intentioned, leaving your weight in Stryd constant will have the opposite effect of what's intended, and will report an inaccurate power number. Remember, the process of converting acceleration to power (f=m*a) is simply Stryd's way of trying to normalize out the effect of weight from the acceleration data it is measuring. In reality, it already "knows" your weight, or at least the combined effect of your true weight and the power you are producing, in the acceleration data is measures.
So, if I want to know if my FTP is increasing or decreasing as my weight is also changing throughout the season, the only way I can accurately do that is to tell Stryd how much I actually weigh so that when it performs its "normalization" calculations to convert acceleration to power is does so accurately.
Thanks @Tom Glynn. Looking only at 3 sec. power was definitely a bit of an experiment, and not something I wanted to attempt in a tri for the first time. My rationale was that I have a decent gauge of power when running steady-state on flat ground so if I glance at my watch every minute or so to sanity-check myself that seems to work pretty well for me. Where I run into problems is on steep ascents or descents (mostly ascents). If I use something like 30 sec. power then I'm already half way up those short but steep rollers and I've "burned a match" before I even realize it, so 3 sec. power helps me level-set effort at the start of a hill. The better solution would be to have both 3 sec. and something longer (1 min?) on the display. On the bike I have 3 sec. and 10 min. power.
The negative-split strategy was also an experiment of sorts, as I wasn't really sure of my true CP. This race was primarily a testing race to reset zones. I didn't want to go out and try to hang on to a number and end up failing spectacularly, so going out a little conservatively and then ramping up was the lower-risk way of creeping up on CP.
This is not a new topic... I was relaying the consensus from a number of other forums that I follow. Steve Palladino regularly tries to explain the topic, many times no more successfully than I have explained it to you.
If you search for "Stryd Weight" in the FB Forums for Stryd or the Paladino Power Forum, you will see the subject discussed again and again... some people never get it. The coaches do get it. The Stryd Admins get it.I am pretty Sure that Ron George and Coggqn and written on this topic too. Steve Bateman published a paper on 'weight-doping' the stryd wind** ( so that treadmill powers = outside powers).
Good luck!
** With the Stryd Wind, weight is also used as part of the algorithm to calculate wind resistance, so weight should be in the ball park.
Hey @Rich Stanbaugh thanks for the link to the paper. I've read more than one discussion on this topic but hadn't seen that paper. I agree that it's been much discussed, though I don't necessarily agree that it's universally accepted. Out of curiosity, I went to see what's discussed over in the FB group, and happened to come across this thread as the first one on the topic (not sure if the link will work):
The ensuing discussion turns into a pretty interesting debate between Palladino and a guy by the name of Paul Stidworthy. No idea who he is, but I found his perspective to be similar to mine. I won't bother rehashing or paraphrasing or any of that. Anyone curious enough can check it out, but I'll just say that my own concerns over this approach are echoed there. Perhaps we'll just have to agree to disagree on this one. All good.
@John Katsoudas Would you mind sharing two data points from your race? What was your Leg Spring Stiffness (LSS) for the first half and the second half? Did the negative split cause a huge drop or was the first half too easy?
Why I'm asking is that I read a really interesting marketing email from Stryd talking about race fatigue and how to prevent it. I've been using this technique to monitor my long runs. For the past few months I have compared LSS on the first and second halves of the run. If there was a large difference, then I was probably going too long too fast and should dial down the effort or distance.
They didn't post the article on the blog or elsewhere so I'll just cut and paste it here.
Presenting the easiest way ever to understand how to prevent race fatigue with Leg Spring Stiffness
I think we oughta rename the term that marathoners ever-so-lovingly use to refer to the difficult part late in the race from “The Wall” to the “Jello Point.”
Why the change?
A) My legs feel like a bowl of wobbly, fresh-out-the-fridge Jello at this point
B) The game plan to beat “The Wall” is as simple as the instructions to make Jello
The solution is simple because one of the most common reasons is I see for "The Wall" is the on-set of muscle fatigue.
And, the game plan to beat muscle fatigue is easy.
You need to work on your Leg Spring Stiffness.
Leg Spring Stiffness is the perfect metric to quantify muscle fatigue & can be the perfect indicator of what kind of experience you can expect on race day.
Let’s take a look at the data.
Example #1: No muscle fatigue → Good race
This marathoner has excellent Leg Spring Stiffness & a great resistance to fatigue.
Over the course of 2+ hours of running, their Leg Spring Stiffness (LSS) declined by less than 1%, which indicates that muscle fatigue did not hinder their performance at all.
How can you achieve a fatigue resistance like this?
You should monitor your LSS in your long runs. After you build up sufficient endurance to run ~17+ miles, you should watch your LSS in the second half of your runs. If you see a drop off, you know that you likely need to focus on more muscle strengthening activities such as running long more often or taking up some supplemental training. Your racing will surely improve if you can shore up weaknesses from muscle fatigue.Example #2: Muscle fatigue → Less-than-optimal race
Here is another marathoner whose performance was limited by fatigue.
While this was not a disastrous race by any stretch for this runner, the data shows that this runner can finish their next race faster & more comfortably if they improve their Leg Spring Stiffness.
They are likely to run a tad bit faster & feel a lot better at the end of the day.
So, the question is, how can you ensure that you are fatigue resistant?
You should monitor your Leg Spring Stiffness with Stryd.
Hey @Tom Glynn - sure, no problem. I've read what you posted about LSS before, but confess that I haven't really monitored LSS closely during my runs. Here's the data:
Miles 0 - 6.5: 10.8KN/m
Miles 6.5 - 13.1: 10.8KN/m
Here's the plot. Stryd Powercenter doesn't let me crop out the warmup jog I did beforehand, but that's the part that's not highlighted at the very beginning of the file, so it's not included in the data. You can see power gradually ramp up and LSS stays flat. Good news, I guess. Interestingly, it seems that LSS seemed to vary the most on the steeper rollers.
@Tom Glynn I'm curious whether you see a drop in LSS on your long runs? Part of the reason I don't really pay attention to LSS is because every time I have looked at it post-run I don't see much of a drop. The answer I'd love to believe is that I'm super-fit 😀 however this is not the likely answer. More likely, I'm either not running hard enough of far enough to elicit a drop in LSS during the course of the run. I'm curious to hear your experience with LSS and what lessons you've learned from monitoring it.
@John Katsoudas I'm not seeing a drop either. I'm always trying to figure out why I tend to slow down in IM runs. I think looking at this metric says that the work I do leading up to the race is good with long runs, etc. So maybe it's nutrition, sodium, hydration or just in my head. As I progress up the mileage to my IM, I've been looking at the 1st and 2nd half LSS stuff to see if Stryd thinks I'm pushing the mileage too hard/too soon.
I'm also trying to figure out my IM run power and I'm leaning to somewhere around 230W. I could definitely run harder, but I'm more interested in practicing IM speed, not marathon speed.
Great insight on evolving metrics here. Thanks @Tom Glynn and @Rich Stanbaugh. I have had significant ‘back-half” success using critical power, however, I have also identified muscle endurance to be an increasing limiter with age. LSS seems to be an important tool to guide my long run training as I prepare to return to the 140.6 distance.
I come from a swimming background, and have recently been using FORM goggles with real-time digital information displayed on the bottom of the pool. I am about to purchase the Polar HRM sensor, and believe that it will improve my ability to guide sub-maximal HR interval training during long swim sets. Look for a forum thread in the future.
@John Culberson Interesting comment on muscle endurance being an increasing limiter with age. I consider myself a pretty good runner for my age and sport (tri versus marathon) and yet my LSS appears to be pretty poor. Steve Palladino wrote an interesting piece on the Stryd metrics. Here is his take on LSS:
==============
Leg Spring Stiffness (LSS)
Leg spring stiffness may be related to physical properties of tendons (such as the Achilles tendon), ligaments and fascia structures (such as the plantar fascia), and myofascial elements. It has been proposed that on loading, during contact through midstance phase of running, these structures store elastic energy. Following midstance, through propulsion, these structures provide some elastic recoil. Hence, these structures may account for some or all of the “spring” effect captured by the metric LSS. The relationship of elastic recoil to LSS, in turn, is likely explanatory of observations that LSS correlates positively with Running Economy.
To compare LSS across runners, it is important to normalize the value to weight, hence LSS/kg. Powercenter does not report LSS/kg - only raw LSS values. However, it is easy to normalize the value using Stryd weight. LSS/kg = LSS divided by Stryd weight in kg. Based on data that I have evaluated, LSS/kg stratification may fit as follows (Table 4).
Table 4. Interpretation / stratification of LSS/kg.
95th percentile 0.173
Above average 0.158
Average 0.143
Below average 0.128
5th percentile 0.113
Comparison Across Runners
Rather than use raw leg spring stiffness, it is better to use LSS/kg at similar intensity when comparing across runners.
Tracking Leg Spring Stiffness
Real-time tracking of leg spring stiffness is not typically available. Instead, leg spring stiffness is tracked in post-hoc analysis, either as a tracing of leg spring stiffness, or as average for leg spring stiffness over the entire run or segments of the run (or laps).
Leg Spring Stiffness Sensitivity to Speed / Relative Intensity
Leg spring stiffness is somewhat sensitive to intensity or speed. It is best to compare your leg spring stiffness across similar intensities and over similar terrain..
Leg Spring Stiffness and Fatigue
Leg spring stiffness may decrease with progressing fatigue.
Interdependence
GCT may interact with leg spring stiffness. Higher leg spring stiffness may be associated with lower GCT.
Manipulating Leg Spring Stiffness
Leg spring stiffness may be improved with plyometrics, skipping drills / jump rope, weight training, and hill running.
===============================================
I rank in the below average bucket. I've been wondering if that is an age thing where there is just a loss of muscle mass over time. Maybe I'm just too heavy and comparing a 165 pound triathlete to a 140 marathoner will never turn out well. How much can I improve LSS by doing other things?
As to your Form swim googles thoughts - I bought mine when they first came out and have been a super fan since day one. Great product and great company. I bought the HR monitor but found it of limited used, just like the HR I use for running or biking. I just don't get a huge variation in my HR when training so I swim along at 120 bpm at 1:30 pace or 2:00 pace.
@Tom Glynn Just wanted to say thanks for all of the great information in this thread. I only started running with Stryd in January so it has been very helpful for me.
@Tom Glynn: Muscles and tendons naturally become less flexible with age. Interesting that my LSS/kg puts me closer to average. I am a large athlete with a swim and bike background and have run consistently for over 40 years within a 10-25 mpw range. I have not had a lot of injury problems... although I have never stretched, nor done much strength work. Perhaps, my relatively slow running speed and steady vs tempo focused gait has preserved some spring? I know that you run quite-a-bit faster than I do, so its an interesting phenomenon. I suspect that ankle strength and flexibility is something that is overlooked as a significant driver of run speed. Plyometrics would likely place more of a focus in that area than standard strength and flexibility programs. Jeff Cuddleback swore-by a device to improve ankle strength (born2run.com). I bought one... but haven’t used it.
@John Culberson Thanks for the thoughts! It's funny you bring up the age thing. I don't think I'm that unusual in that, as a 58 year old, I don't see myself as old. Like most of us here, if you've done a 70.3 or longer, you are fitter than 98% of the people in the world. I'm with you in that I do very little, if any stretching. I warm up, both on the bike and treadmill for 10-15 minutes, but that's about it.
We should have a 20, 30, 40, 50,60 year old all go out and run an all out 5 or 10K and report back on LSS. Think the 20 year old would win?
I just took a look at the device you linked to. We actually have that device! My wife had some foot issues years ago and the PT recommended it. I'm going to pull it out of storage and give it a go.
@Tom Glynn Glad I’m in such good company re: stretching. My warm-ups are getting longer each year. I suspect that improving leg spring is not as important as maintaining it through the distance. I believe your advice to include a second moderately long hilly run each week is sound.
After a longish “Steady” Zn2-3 ride this am, my legs felt “springy” starting my 4mi run this pm. I was forefoot striking fot the first 2.5mi, then dropped back to a typical long distance heel strike. My LSS descended by .5 each of the 4 miles. I was surprised that subjectively, when I felt my best (springy), my leg stiffness was highest (worse) and when I was banging my 190lbs down on my heels, I had a lower (better) LSS. I was certainly pleased that my score descended through the run as my power and pace increased. Anyone experimented with LSS and forefoot/heel strike? Not sure how to interpret this.
Yes - higher LSS is better. LSS should - generally - be worse at the end of a long run than at the start of a run because the tendons have become more elastic.
LSS needs to be looked at on a per kg basis at a minimum. There is a school of thought that LSS should also be normalized by height (LSS/kg/m) - the reason being that longer limbs have longer tendons and will be more elastic.
I watch mine all of the time - it fascinated me for awhile - but haven't figured out what to do with it because it is a modeled number that changes with effort. For example, when I do intervals, the LSS is higher on the hard efforts than the easy efforts... so this makes it more confusing to me to interpret. Chart below shows this. Even Laps were (300m, 300m, 900m) x3, odd laps were (300m, 300m, 600m) x3 jogs. You can see that pace has an impact on LSS. My Stryd weight is 165 and I weigh 152... so the numbers may look different to those of you with different settings.
I have considered trying to improve it through, for example, skipping rope, (small) box jumps, hopping drills, etc. Dr. Keith Baar has done a bunch of original research on tendon/sinew strength/health and shows that it can be improved and should lead to lower injuries. The two big takeaways that I got form his research are:
Tendon strength / resilience is only improved during about the first 8-10 minutes of exercise. He advocates about 3 sessions per day of 8-10 minutes jumping rope, sessions separated by ≈6hrs as an optimal recipe for strengthening lower leg sinews.
Supplements may help - he advocates vitamin c enriched collagen right before sessions to strengthen sinews have been shown to improve outcomes.
Having said all of that - I still am not certain that comparing LSS between individuals is meaningful except in general terms. If my LSS was becoming higher over time - I would view that as positive and confirmation that my leg fitness was improving and that my efficiency may be improving.
More thoughts on Stryd Data. I've always found it rather confusing as to where all the data actually comes from. Is it from your watch, Stryd, somewhere else? If there are multiple sources, which takes precedent? For example my Garmin 935 watch has been showing bad elevation data for a while and it took a while to figure out the problem is with Garmin, not Stryd. Here is an interesting article I came across a year or so ago that walks through some of the issues
Garmin Watches - Pace/Distance/Cadence from Stryd vs. GPS
In order to understand when you are getting pace readings, distance readings, cadence readings from Stryd (and when you are getting them from GPS) on Garmin watches the below notes may help, as I was very confused when I first started. Most of this information is from others, but I wanted to compile it due to my own confusion, so correct me if I am mistaken (credit: @kun, @angus,fellrnr.com1 and garmin support).
Summary
-In order to get distance from a footpod (Stryd) you need to disable GPS either in the app settings or on your watch (not sure if this is possible for any watch) or set the distance to always in the footpod setup (only available on some watches) (see ‘Distance Order of Operation’ for full logic of how Stryd IQ and Run apps record distance).
-In order to get pace from the footpod (Stryd) you need to either disable GPS (in app or on the watch), or if this option is available for your watch set the speed (pace) to always from footpod (in sensor settings when you pair it, not available on all watches).
-In order to get cadence from the footpod (Stryd), pair Stryd as footpod, it should come by default if a footpod is paired, as footpods take precedence over the internal accelerometer when present.
Distance Order of Operation (Where Distance Comes From in Garmin Watches)
Garmin watches (in default run app, and Stryd IQ app) will get distance first from GPS if available and not turned off, unless your watch allows you to set the distance to always in the footpod setup under settings. If a GPS path is recorded when you sync, then distance is coming from GPS not Stryd, unless you have a watch that allows you to set the distance to always in the footpod setup.
If GPS is unavailable (or disabled) or the footpod distance is set to always, then the watch will get distance from the footpod if present.
If GPS is unavailable (or disabled), and a footpod is unavailable, then distance will come from the internal accelerometer. The internal accelerometer is auto calibrated from GPS running.
Pace Order of Operation (Where Pace Comes From in Garmin Watches)
Garmin watches (in default run app, and Stryd IQ app) will get speed (pace) first from GPS if available (and not turned off), unless your watch has the option (in sensor settings when you pair it) to get the pace from the footpod as ‘always’ then pace will always come from Stryd instead of GPS.
If GPS is unavailable (or disabled), or footpod pace is set to ‘always’ (in sensor settings) then pace will come from footpod.
If GPS is unavailable (or disabled), and a footpod is unavailable, then pace will come from the internal accelerometer. The internal accelerometer is auto calibrated from GPS running.
Cadence Order of Operation (Where Cadence Comes From in Garmin Watches)
If a footpod is present then pace will come from footpod (Stryd).
If a footpod is unavailable, then pace will come from the internal accelerometer. If cadence comes from the internal accelerometer then your arms must be moving in rhythm with your feet to get correct cadence, so the internal accelerometer is not measuring foot cadence like a Stryd does but rather arm cadence.
Note: If it is available (not all watches have these options), auto calibrate should be off, calibration factor should be 100 (unless you do a better track calibration session), speed (pace) should always come from the footpod, and distance should always come from the footpod.
By default this app gets the pace/distance from GPS, in order to get all data from Stryd you need to disable GPS on your watch, or set the distance to come from the footpod (setting not available on all watches). Thus if you see a path in your synced data you are not getting distance from Stryd (unless you can set your distance to always in the foot pod sensor settings area in your Garmin Watch, see ‘Distance Order of Operation’), and possibly pace (unless you can set your pace to always in the foot pod sensor settings area in your Garmin watch, see ‘Pace Order of Operation’). See the ‘Distance Order of Operation’ and ‘Pace Order of Operation’ to understand when you are getting distance and pace from Stryd and when you are getting distance and pace from GPS. This app does not have any settings that allow you to totally disable GPS, thus you cannot get distance values using this app from Stryd unless you watch allows you to set distance to always under the footpod sensor setup, and you cannot get pace unless your watch supports the pace from footpod always option (see ‘Pace Order of Operation’).
This data field must be added to Garmin’s default Run or Run Indoor app as a data field, to allow the recording of advanced Stryd data such as power, VO… This data field allows users to see power in the default run applications, and allows all Stryd metrics to be saved with your run, so you should definitely add it.
Garmin Run or Run Indoor App (Default installed Run and Run Indoor apps)
In the app settings there is an option to disable GPS, if GPS is disabled then pace & distance & cadence will all come from Stryd if paired (See the ‘Distance Order of Operation’ and ‘Pace Order of Operation’ to determine when you can get distance and pace from Stryd vs. GPS). If you add the Stryd Power Data Field (above) as one of the data fields for this app, data such as power/VO… will be recorded alongside other data (so if you have a Stryd you should always add this as a field even if it is on a screen you don’t look at much).
Note: With GPS disabled these 2 apps are the same functionally, but you can have different fields setup if you prefer to see different things in indoor vs outdoor running modes.
Settings - if you want pace, distance, and cadence from Stryd (GPS enabled) (only certain watches that support distance=always, and speed=always under footpod setup)
I want to see all my data (pace, distance, cadence) from the more accurate Stryd sensor, and I have a watch that allows me to get set distance=always, speed=always in the footpod, thus below are my recommendations for setup:
Download the Stryd IQ app, use this app when running. Alternatively you can install the Stryd Power Connect IQ Data Field, and use the default run app on the watch - make sure you add the Stryd Power Connect IQ Data Field as one of the data fields on your run app under its’ settings to get all the Stryd data when you sync.
Sync data with Garmin Connect app on your phone, ensure Stryd PowerCenter is setup to import data from Garmin to see your data in Stryd PowerCenter.
Settings - if you want pace, distance, and cadence from Stryd (GPS disabled)
I want to see all my data (pace, distance, cadence) from the more accurate Stryd sensor, thus below are my recommendations for setup:
Use the default ‘Run Indoor’ app from Garmin (GPS is disabled in this app since it is an indoor app). Ensure GPS is turned off in the app settings to ensure distance & pace come from Stryd not GPS.
Sync data with Garmin Connect app on your phone, ensure Stryd PowerCenter is setup to import data from Garmin to see your data in Stryd PowerCenter.
Settings - if you want pace, and cadence from Stryd, but distance from GPS (not available on all watches)
With some Garmin watches it is possible to get pace, and cadence from Stryd while retaining GPS map of where you ran. However with this you are getting the total distance from GPS not from Stryd. This is possible if you watch has the setting avialable under settings --> sensor (when you pair Stryd to your watch), that says something like ‘get pace (speed) from footpod’ --> set this to ‘always’, to allow the footpod pace to overrule the GPS for pace. If you have a watch that gives you the option to get distance from the footpod when you set it up, select always, and look at the first settings section above since you do not have to disable GPS to get everything from Stryd.
Use the default ‘Run’ app from Garmin. Ensure GPS is turned on in the app settings to allow GPS data to be logged, this will get distance from GPS but pace from footpod (as long as pace from footpod is set to always).
Sync data with Garmin Connect app on your phone, ensure Stryd PowerCenter is setup to import data from Garmin to see your data in Stryd PowerCenter.
Documentation of Sources of Information
Chat with Garmin Support (3/23/2018):
jctosu:
I have a vivoactive HR, I would like to get pace & distance & cadence from my foot pod (Stryd). This foot pod is paired as a footpod in settings–>sensors. If I disable GPS in run mode, and the foot pod is connected, then does pace & distance & cadence come from the foot pod as the 1st choice?
Inder:
Yes, That is correct. Once the GPS is disabled all information will come from the Footpod.
Vivoactive HR User Manual:
Foot Pod
Your device is compatible with the foot pod. You can use the foot pod to record pace and distance instead of using GPS when you are training indoors or when your GPS signal is weak. The foot pod is on standby and ready to send data (like the heart rate monitor).
After 30 minutes of inactivity, the foot pod powers off to conserve the battery. When the battery is low, a message appears on your device. Approximately five hours of battery life remain.
Information on How to Pair Several Watches with Stryd:
How to Determine What Features Your Watch (or pre-purchase has)
If you are trying to figure out how to setup your watch properly or determine if a watch has the features you want, find the user manual online by search ‘vivoactive HR user manual’, and look for the ANT+ Sensors --> Footpod section, under this section the user manual will go over what features are available. In the examples below you can see the vivoactive HR does not support speed nor distance from footpod, but in the Fenix 5X user manual there is a section of the user manual that goes over setting speed and distance options for the footpod so you can see that you can always get speed (pace) and distance from the footpod instead of GPS if you set those options correctly.
Comments
Quick question for the Stryd users if you also use TrainingPeaks. Do you follow/ use Stryd's RSS (running stress score) or TP's TSS? I've historically ignored the Stryd RSS figure in lieu of TSS.
I did a 85-min run yesterday and for example, my RSS was 92 and my TSS for the run was 157. Given I use TP for all swim, bike, run, I can't say I'd ever concern myself with RSS.
Is there something I'm perhaps missing?
@Jeff Phillips I use tss, but I also do not see so much difference between the two.
It seems like something is askew with your zone settings in TrainingPeaks if it gave you 157 TSS for 1:25 of running. 1 hour of running at threshold would give you 100 TSS. 157 TSS from 1:25 implies that your ran at an IF of 105%.
Check if you have run power threshold set to your Critical Power from Stryd... that should make the numbers a lot closer.
@Jeff Phillips, my RSS is usually a bit lower but still comparable to TSS. Yesterday's 1h20 min easy long run at 80% of CP gave me 67 RSS and 84 TSS.
Last Tuesday hard 3 x 1 mile came very close at 89 TSS / 87 RSS.
I've been following along with fascination. Thanks to everyone that's contributed so far. @Rich Stanbaugh I'm still not sure I follow the logic of not changing weight in Stryd as your weight changes. To use your example, if I ran ran the same course in the same time on two different occasions, but on the second occasion I was 2 Kg lighter, then by definition I was putting out less power the second time. If I was 2 Kg lighter the second time and I put out the same power as the first run, I would expect to run a faster time. So while the conclusion of the hypothetical example seems inconvenient (having to constantly change zones as weight changes), logically it seems correct to me. Otherwise, Stryd is assuming that you're accelerating more or less mass than you actually are.
What would be nice is if Stryd could import data from the Healthmate app (Withings scales) the same way that Zwift does. I make it a point to get on the scale 3-4 times per week, so my weight in Zwift is alway pretty accurate.
On a personal note, I ran the Santa Cruz half marathon yesterday, and decided I'd use this as an experiment in pacing solely with power and RPE. I set my Garmin 935 to have a screen with a single field: 3 sec. power. No HR, no pace, no time... nada. Focus on what I can control in the moment. Stryd Powercenter had my CP at 254 and their guidance is to pace a HM at ~95% of CP, so my goal was to run the first 6 miles at 240-245W and then see if I could bump it up slightly from there.
Miles 1 - 6 (avg. Watts): 235, 243, 245, 245, 247, 242 (mile 6 was a narrow path and I got stuck in a crowd).
Miles, 7 - 13: 254, 247, 262, 258, 263, 263, 269
Looking at the file post-race, HR stayed pretty flat through mile 9, at which point it started drifting upward to a max of 185 in the final mile. Had I looked down in mile 13 and seen an HR in the mid-180's I suspect I might have subconsciously eased up a tad. Who knows.
In the end I hit all three of my goals for the day:
(1) I established a new current CP as I transition from OS to HIM plan (new CP is now 262 Watts)
(2) I beat my time goal by several minutes (Vaporfly 4% assisted 😀)
(3) I negative split the race. Not sure it's necessarily the fastest way to run a race, as it involves intentionally holding back for 1/2 the race but it's very satisfying to be ramping up the pace as everyone around you starts to fall apart.
Great race @John Katsoudas! I paced an open half marathon last year and the run leg of a HIM solely on power due to the rolling nature of both courses. It works!
@Rich Stanbaugh Thanks for your note. I went into TP and saw I had two speed settings selected -- a pace for "Default Speed/ Pace" and also a a different value for "Run Speed/ Pace".
Which do you all use in TP?
@John Katsoudas I understand the confusion. The bottom line is that Weight changes overnight... FTP / CP does not change over night.
We are using power meters (whether bike or Stryd) to give us guidance about our metabolism (eg FTP / VO2) to help us plan and execute training and races.
The power numbers that we see are a visible number that reflects our level of output and this number has meaning to us relative to what we understand out thresholds to be.
The confusion comes because:
The reality is that Stryd measures acceleration and computes force from mass * acceleration (versus a bicycle power meters measure force directly based on how hard you press the pedals). In order for us to interpret the Stryd power numbers the way that we have become accustomed to with bike power numbers, we need to hold the weight constant so that we can observe changes in power that relate to changes in fitness.
From what I have read, the guidance is generally to set your weight for something in the middle of race weight / early season weight and leave it. If it is necessary to change your weight setting, this should be done prior to beginning a training block.
Changing your Stryd weight do not do anything to enhance your training, your fitness or your insights into your training / fitness.
@Rich Stanbaugh I guess I'm still not following. These two statements seem to me to be at odds with each other:
1) Stryd doesn't measure power, it measures acceleration and then derives power,
and
2) we need to hold the weight constant so that we can observe changes in power that relate to changes in fitness
If what Stryd is reporting as "power" is a derivation of mass*acceleration, and you feed it incorrect information about mass, then you will get incorrect information about derived power. You won't be able to observe changes in fitness using this data, since you won't know if the observed change in derived power is a result of changes in your body weight or your fitness (or both).
@John Katsoudas Congrats on a great race with power. Pretty interesting that you went with 3 second power only. I find that jumps around quite a bit for me, especially if I zone out for a period of time. I have the Stryd Zones Garmin Connect IQ which allows you to pick between real time, 3 second averaging, 10 second averaging, 30 second averaging, lap power, and overall power display options. I have mine showing 3 second and lap power. I tend to watch lap power most. Every mile lap then shows lap pace and lap time, which I tend to ignore.
Your strategy of negative splitting the race is probably better than mine, which is go out strong and hold on for as long as I can!
Stryd will tell you that even splitting is the way to go: https://blog.stryd.com/2020/01/23/every-world-record-from-1500m-to-marathon-was-set-via-even-pacing/
Tom
@John Katsoudas you are on the right track - just need to look at the other variable. Acceleration.
Changes in fitness, eg, ftp, correlate well with changes in the acceleration that Stryd measures. They do not correlate well with changes in weight (ie, I can lose 5# and be faster, but that doesn't relate to a change in ftp).
The underlying question here is "how do we extract meaningful information from these devices?"
Weight change is meaningful - but it is not meaningful to predict changes in ftp. Weight change is meaningful when predicting how fast we can climb a hill, but it is not meaningful when estimating changes in VO2.
If we want to estimate accurately the number of watts you produce during a run, having an accurate weight setting is meaningful. However, if we are trying to measure how much your fitness has changed over the last weeks of training, weight change does not help predict that.
This was a confusing topic for me the first time through it too. Instinctively, I am that Type A personality that things more is better.
The key is that we are using the Stryd to measure changes in fitness and to drive our training. Changing the weight setting shifts all of our existing data (CP, zones, power at certain paces, etc) so that there isn't a straight-forward way to interpret it.
A practical example of this - over the course of an IM build, I develop a feel for the watts I can run off the bike (which power I should run the first 10', what my steady run target will be, etc.) and also what HR or pace that I can expect for certain powers on flat ground. This is all helpful during a race, because it gives me context to understand / interpret what is going on at the moment.
If I changed my Stryd Weight each time I weighed myself, I wouldn't have any of that context. Last week, maybe my ROB (run off bike) power was 250w. This week I lose 5# so my ROB target is 240w. next week I am back up 2#... it goes on and on. The numbers keep changing because weight is changing - but this is creating noise. My fitness hasn't changed in concert with the number changes. The reason we are using the device is related to our fitness / ability to perform.
The general consensus on this in the Stryd forums / Palladino forum is to set the weight at a mid-plan weight and leave it. If you feel the need to change it, change it before a build or at some point in time where the auto-cp function has plenty of time (weeks of runs) to recalculate a new cp.
I love losing weight. I know it will make me faster. I keep a chart that shows me how much I have lost (and don't chart when I gain!!!). Weight chart for weight - FTP/CP chart for FTP/CP... two different things.
If you disagree - then change your weight daily... are we in the same age group?? 😁
@Rich Stanbaugh I completely agree with what you're saying about using devices (any devices) for the big-picture purpose of measuring changes in fitness. Not to belabor the point, but where I'm getting hung up is in the process of arriving at a meaningful power number that accurately represents the work being done so that we can understand if fitness is actually changing.
As you mentioned, Stryd measures acceleration, and then calculates power from that. Physics dictates that for an equivalent force a lighter mass will accelerate more than a heavier mass. In plain English, if your power stays constant but you lose weight, Stryd will directly measure this as an increase in acceleration. If you tell Stryd that you lost weight, it will say "aha! I see that acceleration is higher, but this is because the weight is lower, so I will normalize this out and report the same amount of power." If, on the other hand, you leave your weight in Stryd constant, it will see the higher acceleration, and incorrectly interpret that as a higher power because it believes your weight stayed constant. So, while well-intentioned, leaving your weight in Stryd constant will have the opposite effect of what's intended, and will report an inaccurate power number. Remember, the process of converting acceleration to power (f=m*a) is simply Stryd's way of trying to normalize out the effect of weight from the acceleration data it is measuring. In reality, it already "knows" your weight, or at least the combined effect of your true weight and the power you are producing, in the acceleration data is measures.
So, if I want to know if my FTP is increasing or decreasing as my weight is also changing throughout the season, the only way I can accurately do that is to tell Stryd how much I actually weigh so that when it performs its "normalization" calculations to convert acceleration to power is does so accurately.
Edit: Here's what Stryd has to say on the subject. https://support.stryd.com/hc/en-us/articles/360007602474-If-my-weight-is-different-than-what-is-programmed-on-Stryd-how-does-that-affect-power-reading-
Thanks @Tom Glynn. Looking only at 3 sec. power was definitely a bit of an experiment, and not something I wanted to attempt in a tri for the first time. My rationale was that I have a decent gauge of power when running steady-state on flat ground so if I glance at my watch every minute or so to sanity-check myself that seems to work pretty well for me. Where I run into problems is on steep ascents or descents (mostly ascents). If I use something like 30 sec. power then I'm already half way up those short but steep rollers and I've "burned a match" before I even realize it, so 3 sec. power helps me level-set effort at the start of a hill. The better solution would be to have both 3 sec. and something longer (1 min?) on the display. On the bike I have 3 sec. and 10 min. power.
The negative-split strategy was also an experiment of sorts, as I wasn't really sure of my true CP. This race was primarily a testing race to reset zones. I didn't want to go out and try to hang on to a number and end up failing spectacularly, so going out a little conservatively and then ramping up was the lower-risk way of creeping up on CP.
@John Katsoudas
This is not a new topic... I was relaying the consensus from a number of other forums that I follow. Steve Palladino regularly tries to explain the topic, many times no more successfully than I have explained it to you.
Here is a paper that he wrote on the subject.
If you search for "Stryd Weight" in the FB Forums for Stryd or the Paladino Power Forum, you will see the subject discussed again and again... some people never get it. The coaches do get it. The Stryd Admins get it.I am pretty Sure that Ron George and Coggqn and written on this topic too. Steve Bateman published a paper on 'weight-doping' the stryd wind** ( so that treadmill powers = outside powers).
Good luck!
** With the Stryd Wind, weight is also used as part of the algorithm to calculate wind resistance, so weight should be in the ball park.
Hey @Rich Stanbaugh thanks for the link to the paper. I've read more than one discussion on this topic but hadn't seen that paper. I agree that it's been much discussed, though I don't necessarily agree that it's universally accepted. Out of curiosity, I went to see what's discussed over in the FB group, and happened to come across this thread as the first one on the topic (not sure if the link will work):
The ensuing discussion turns into a pretty interesting debate between Palladino and a guy by the name of Paul Stidworthy. No idea who he is, but I found his perspective to be similar to mine. I won't bother rehashing or paraphrasing or any of that. Anyone curious enough can check it out, but I'll just say that my own concerns over this approach are echoed there. Perhaps we'll just have to agree to disagree on this one. All good.
-John
@John Katsoudas Would you mind sharing two data points from your race? What was your Leg Spring Stiffness (LSS) for the first half and the second half? Did the negative split cause a huge drop or was the first half too easy?
Why I'm asking is that I read a really interesting marketing email from Stryd talking about race fatigue and how to prevent it. I've been using this technique to monitor my long runs. For the past few months I have compared LSS on the first and second halves of the run. If there was a large difference, then I was probably going too long too fast and should dial down the effort or distance.
They didn't post the article on the blog or elsewhere so I'll just cut and paste it here.
=============================================================================
Presenting the easiest way ever to understand how to prevent race fatigue with Leg Spring Stiffness
I think we oughta rename the term that marathoners ever-so-lovingly use to refer to the difficult part late in the race from “The Wall” to the “Jello Point.”
Why the change?
A) My legs feel like a bowl of wobbly, fresh-out-the-fridge Jello at this point
B) The game plan to beat “The Wall” is as simple as the instructions to make Jello
The solution is simple because one of the most common reasons is I see for "The Wall" is the on-set of muscle fatigue.
And, the game plan to beat muscle fatigue is easy.
You need to work on your Leg Spring Stiffness.
Leg Spring Stiffness is the perfect metric to quantify muscle fatigue & can be the perfect indicator of what kind of experience you can expect on race day.
Let’s take a look at the data.
Example #1: No muscle fatigue → Good race
This marathoner has excellent Leg Spring Stiffness & a great resistance to fatigue.
Over the course of 2+ hours of running, their Leg Spring Stiffness (LSS) declined by less than 1%, which indicates that muscle fatigue did not hinder their performance at all.
How can you achieve a fatigue resistance like this?
You should monitor your LSS in your long runs. After you build up sufficient endurance to run ~17+ miles, you should watch your LSS in the second half of your runs. If you see a drop off, you know that you likely need to focus on more muscle strengthening activities such as running long more often or taking up some supplemental training. Your racing will surely improve if you can shore up weaknesses from muscle fatigue.Example #2: Muscle fatigue → Less-than-optimal race
Here is another marathoner whose performance was limited by fatigue.
While this was not a disastrous race by any stretch for this runner, the data shows that this runner can finish their next race faster & more comfortably if they improve their Leg Spring Stiffness.
They are likely to run a tad bit faster & feel a lot better at the end of the day.
So, the question is, how can you ensure that you are fatigue resistant?
You should monitor your Leg Spring Stiffness with Stryd.
Hey @Tom Glynn - sure, no problem. I've read what you posted about LSS before, but confess that I haven't really monitored LSS closely during my runs. Here's the data:
Miles 0 - 6.5: 10.8KN/m
Miles 6.5 - 13.1: 10.8KN/m
Here's the plot. Stryd Powercenter doesn't let me crop out the warmup jog I did beforehand, but that's the part that's not highlighted at the very beginning of the file, so it's not included in the data. You can see power gradually ramp up and LSS stays flat. Good news, I guess. Interestingly, it seems that LSS seemed to vary the most on the steeper rollers.
@Tom Glynn I'm curious whether you see a drop in LSS on your long runs? Part of the reason I don't really pay attention to LSS is because every time I have looked at it post-run I don't see much of a drop. The answer I'd love to believe is that I'm super-fit 😀 however this is not the likely answer. More likely, I'm either not running hard enough of far enough to elicit a drop in LSS during the course of the run. I'm curious to hear your experience with LSS and what lessons you've learned from monitoring it.
@John Katsoudas I'm not seeing a drop either. I'm always trying to figure out why I tend to slow down in IM runs. I think looking at this metric says that the work I do leading up to the race is good with long runs, etc. So maybe it's nutrition, sodium, hydration or just in my head. As I progress up the mileage to my IM, I've been looking at the 1st and 2nd half LSS stuff to see if Stryd thinks I'm pushing the mileage too hard/too soon.
I'm also trying to figure out my IM run power and I'm leaning to somewhere around 230W. I could definitely run harder, but I'm more interested in practicing IM speed, not marathon speed.
Long run info:
1/19 16 miles, 252 watts 9.2 / 9.1
1/26 18 miles, 226 watts 9.1 / 9.2
2/2 16 miles, 230 watts 9.2 / 9.2
2/9 16 miles, 230 watts 9.2 / 9.2
2/16 16 miles, 232 watts 9.3 / 9.1
2/23 18 miles, 231 watts 9.1 / 9.0
Tom
Great insight on evolving metrics here. Thanks @Tom Glynn and @Rich Stanbaugh. I have had significant ‘back-half” success using critical power, however, I have also identified muscle endurance to be an increasing limiter with age. LSS seems to be an important tool to guide my long run training as I prepare to return to the 140.6 distance.
I come from a swimming background, and have recently been using FORM goggles with real-time digital information displayed on the bottom of the pool. I am about to purchase the Polar HRM sensor, and believe that it will improve my ability to guide sub-maximal HR interval training during long swim sets. Look for a forum thread in the future.
@John Culberson Interesting comment on muscle endurance being an increasing limiter with age. I consider myself a pretty good runner for my age and sport (tri versus marathon) and yet my LSS appears to be pretty poor. Steve Palladino wrote an interesting piece on the Stryd metrics. Here is his take on LSS:
==============
Leg Spring Stiffness (LSS)
Leg spring stiffness may be related to physical properties of tendons (such as the Achilles tendon), ligaments and fascia structures (such as the plantar fascia), and myofascial elements. It has been proposed that on loading, during contact through midstance phase of running, these structures store elastic energy. Following midstance, through propulsion, these structures provide some elastic recoil. Hence, these structures may account for some or all of the “spring” effect captured by the metric LSS. The relationship of elastic recoil to LSS, in turn, is likely explanatory of observations that LSS correlates positively with Running Economy.
To compare LSS across runners, it is important to normalize the value to weight, hence LSS/kg. Powercenter does not report LSS/kg - only raw LSS values. However, it is easy to normalize the value using Stryd weight. LSS/kg = LSS divided by Stryd weight in kg. Based on data that I have evaluated, LSS/kg stratification may fit as follows (Table 4).
Table 4. Interpretation / stratification of LSS/kg.
95th percentile 0.173
Above average 0.158
Average 0.143
Below average 0.128
5th percentile 0.113
Comparison Across Runners
Rather than use raw leg spring stiffness, it is better to use LSS/kg at similar intensity when comparing across runners.
Tracking Leg Spring Stiffness
Real-time tracking of leg spring stiffness is not typically available. Instead, leg spring stiffness is tracked in post-hoc analysis, either as a tracing of leg spring stiffness, or as average for leg spring stiffness over the entire run or segments of the run (or laps).
Leg Spring Stiffness Sensitivity to Speed / Relative Intensity
Leg spring stiffness is somewhat sensitive to intensity or speed. It is best to compare your leg spring stiffness across similar intensities and over similar terrain..
Leg Spring Stiffness and Fatigue
Leg spring stiffness may decrease with progressing fatigue.
Interdependence
GCT may interact with leg spring stiffness. Higher leg spring stiffness may be associated with lower GCT.
Manipulating Leg Spring Stiffness
Leg spring stiffness may be improved with plyometrics, skipping drills / jump rope, weight training, and hill running.
===============================================
I rank in the below average bucket. I've been wondering if that is an age thing where there is just a loss of muscle mass over time. Maybe I'm just too heavy and comparing a 165 pound triathlete to a 140 marathoner will never turn out well. How much can I improve LSS by doing other things?
As to your Form swim googles thoughts - I bought mine when they first came out and have been a super fan since day one. Great product and great company. I bought the HR monitor but found it of limited used, just like the HR I use for running or biking. I just don't get a huge variation in my HR when training so I swim along at 120 bpm at 1:30 pace or 2:00 pace.
One of the great things about power meters, both cycling and running is that they allow prescriptive rather than descriptive workout planning.
@Tom Glynn Just wanted to say thanks for all of the great information in this thread. I only started running with Stryd in January so it has been very helpful for me.
@Tom Glynn: Muscles and tendons naturally become less flexible with age. Interesting that my LSS/kg puts me closer to average. I am a large athlete with a swim and bike background and have run consistently for over 40 years within a 10-25 mpw range. I have not had a lot of injury problems... although I have never stretched, nor done much strength work. Perhaps, my relatively slow running speed and steady vs tempo focused gait has preserved some spring? I know that you run quite-a-bit faster than I do, so its an interesting phenomenon. I suspect that ankle strength and flexibility is something that is overlooked as a significant driver of run speed. Plyometrics would likely place more of a focus in that area than standard strength and flexibility programs. Jeff Cuddleback swore-by a device to improve ankle strength (born2run.com). I bought one... but haven’t used it.
@John Culberson Thanks for the thoughts! It's funny you bring up the age thing. I don't think I'm that unusual in that, as a 58 year old, I don't see myself as old. Like most of us here, if you've done a 70.3 or longer, you are fitter than 98% of the people in the world. I'm with you in that I do very little, if any stretching. I warm up, both on the bike and treadmill for 10-15 minutes, but that's about it.
We should have a 20, 30, 40, 50,60 year old all go out and run an all out 5 or 10K and report back on LSS. Think the 20 year old would win?
I just took a look at the device you linked to. We actually have that device! My wife had some foot issues years ago and the PT recommended it. I'm going to pull it out of storage and give it a go.
Tom
@Tom Glynn Glad I’m in such good company re: stretching. My warm-ups are getting longer each year. I suspect that improving leg spring is not as important as maintaining it through the distance. I believe your advice to include a second moderately long hilly run each week is sound.
After a longish “Steady” Zn2-3 ride this am, my legs felt “springy” starting my 4mi run this pm. I was forefoot striking fot the first 2.5mi, then dropped back to a typical long distance heel strike. My LSS descended by .5 each of the 4 miles. I was surprised that subjectively, when I felt my best (springy), my leg stiffness was highest (worse) and when I was banging my 190lbs down on my heels, I had a lower (better) LSS. I was certainly pleased that my score descended through the run as my power and pace increased. Anyone experimented with LSS and forefoot/heel strike? Not sure how to interpret this.
Isn't higher LSS "better"?
@John Culberson
@Tom Glynn
Yes - higher LSS is better. LSS should - generally - be worse at the end of a long run than at the start of a run because the tendons have become more elastic.
LSS needs to be looked at on a per kg basis at a minimum. There is a school of thought that LSS should also be normalized by height (LSS/kg/m) - the reason being that longer limbs have longer tendons and will be more elastic.
I watch mine all of the time - it fascinated me for awhile - but haven't figured out what to do with it because it is a modeled number that changes with effort. For example, when I do intervals, the LSS is higher on the hard efforts than the easy efforts... so this makes it more confusing to me to interpret. Chart below shows this. Even Laps were (300m, 300m, 900m) x3, odd laps were (300m, 300m, 600m) x3 jogs. You can see that pace has an impact on LSS. My Stryd weight is 165 and I weigh 152... so the numbers may look different to those of you with different settings.
I have considered trying to improve it through, for example, skipping rope, (small) box jumps, hopping drills, etc. Dr. Keith Baar has done a bunch of original research on tendon/sinew strength/health and shows that it can be improved and should lead to lower injuries. The two big takeaways that I got form his research are:
Having said all of that - I still am not certain that comparing LSS between individuals is meaningful except in general terms. If my LSS was becoming higher over time - I would view that as positive and confirmation that my leg fitness was improving and that my efficiency may be improving.
Thanks @Rich Stanbaugh! Sorry @Robert Sabo, Higher LSS is better... I was not thinking clearly 😩
More thoughts on Stryd Data. I've always found it rather confusing as to where all the data actually comes from. Is it from your watch, Stryd, somewhere else? If there are multiple sources, which takes precedent? For example my Garmin 935 watch has been showing bad elevation data for a while and it took a while to figure out the problem is with Garmin, not Stryd. Here is an interesting article I came across a year or so ago that walks through some of the issues
Garmin Watches - Pace/Distance/Cadence from Stryd vs. GPS
blob:https://endurancenation.vanillacommunities.com/b3a671ab-13e5-4024-a1c9-120133deaa5dRobijn Hage 1 minute ago·Updated
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In order to understand when you are getting pace readings, distance readings, cadence readings from Stryd (and when you are getting them from GPS) on Garmin watches the below notes may help, as I was very confused when I first started. Most of this information is from others, but I wanted to compile it due to my own confusion, so correct me if I am mistaken (credit: @kun, @angus,fellrnr.com1 and garmin support).
Summary
-In order to get distance from a footpod (Stryd) you need to disable GPS either in the app settings or on your watch (not sure if this is possible for any watch) or set the distance to always in the footpod setup (only available on some watches) (see ‘Distance Order of Operation’ for full logic of how Stryd IQ and Run apps record distance).
-In order to get pace from the footpod (Stryd) you need to either disable GPS (in app or on the watch), or if this option is available for your watch set the speed (pace) to always from footpod (in sensor settings when you pair it, not available on all watches).
-In order to get cadence from the footpod (Stryd), pair Stryd as footpod, it should come by default if a footpod is paired, as footpods take precedence over the internal accelerometer when present.
Distance Order of Operation (Where Distance Comes From in Garmin Watches)
Pace Order of Operation (Where Pace Comes From in Garmin Watches)
Cadence Order of Operation (Where Cadence Comes From in Garmin Watches)
How to Pair Stryd with Your Garmin Watch [see articles: https://support.stryd.com/hc/en-us/sections/360000206994-Step-3-Connect-with-your-Garmin-Watch]
Note: If it is available (not all watches have these options), auto calibrate should be off, calibration factor should be 100 (unless you do a better track calibration session), speed (pace) should always come from the footpod, and distance should always come from the footpod.
Stryd IQ Connect IQ App
(https://apps.garmin.com/en-US/apps/14cc7713-eff0-4136-a643-ac88baf99d02)
By default this app gets the pace/distance from GPS, in order to get all data from Stryd you need to disable GPS on your watch, or set the distance to come from the footpod (setting not available on all watches). Thus if you see a path in your synced data you are not getting distance from Stryd (unless you can set your distance to always in the foot pod sensor settings area in your Garmin Watch, see ‘Distance Order of Operation’), and possibly pace (unless you can set your pace to always in the foot pod sensor settings area in your Garmin watch, see ‘Pace Order of Operation’). See the ‘Distance Order of Operation’ and ‘Pace Order of Operation’ to understand when you are getting distance and pace from Stryd and when you are getting distance and pace from GPS. This app does not have any settings that allow you to totally disable GPS, thus you cannot get distance values using this app from Stryd unless you watch allows you to set distance to always under the footpod sensor setup, and you cannot get pace unless your watch supports the pace from footpod always option (see ‘Pace Order of Operation’).
Stryd Power Connect IQ Data Field
(https://apps.garmin.com/en-US/apps/660a581e-5301-460c-8f2f-034c8b6dc90f1)
This data field must be added to Garmin’s default Run or Run Indoor app as a data field, to allow the recording of advanced Stryd data such as power, VO… This data field allows users to see power in the default run applications, and allows all Stryd metrics to be saved with your run, so you should definitely add it.
Garmin Run or Run Indoor App (Default installed Run and Run Indoor apps)
In the app settings there is an option to disable GPS, if GPS is disabled then pace & distance & cadence will all come from Stryd if paired (See the ‘Distance Order of Operation’ and ‘Pace Order of Operation’ to determine when you can get distance and pace from Stryd vs. GPS). If you add the Stryd Power Data Field (above) as one of the data fields for this app, data such as power/VO… will be recorded alongside other data (so if you have a Stryd you should always add this as a field even if it is on a screen you don’t look at much).
Note: With GPS disabled these 2 apps are the same functionally, but you can have different fields setup if you prefer to see different things in indoor vs outdoor running modes.
Settings - if you want pace, distance, and cadence from Stryd (GPS enabled) (only certain watches that support distance=always, and speed=always under footpod setup)
I want to see all my data (pace, distance, cadence) from the more accurate Stryd sensor, and I have a watch that allows me to get set distance=always, speed=always in the footpod, thus below are my recommendations for setup:
Settings - if you want pace, distance, and cadence from Stryd (GPS disabled)
I want to see all my data (pace, distance, cadence) from the more accurate Stryd sensor, thus below are my recommendations for setup:
Settings - if you want pace, and cadence from Stryd, but distance from GPS (not available on all watches)
With some Garmin watches it is possible to get pace, and cadence from Stryd while retaining GPS map of where you ran. However with this you are getting the total distance from GPS not from Stryd. This is possible if you watch has the setting avialable under settings --> sensor (when you pair Stryd to your watch), that says something like ‘get pace (speed) from footpod’ --> set this to ‘always’, to allow the footpod pace to overrule the GPS for pace. If you have a watch that gives you the option to get distance from the footpod when you set it up, select always, and look at the first settings section above since you do not have to disable GPS to get everything from Stryd.
Documentation of Sources of Information
Chat with Garmin Support (3/23/2018):
jctosu:
I have a vivoactive HR, I would like to get pace & distance & cadence from my foot pod (Stryd). This foot pod is paired as a footpod in settings–>sensors. If I disable GPS in run mode, and the foot pod is connected, then does pace & distance & cadence come from the foot pod as the 1st choice?
Inder:
Yes, That is correct. Once the GPS is disabled all information will come from the Footpod.
Vivoactive HR User Manual:
Foot Pod
Your device is compatible with the foot pod. You can use the foot pod to record pace and distance instead of using GPS when you are training indoors or when your GPS signal is weak. The foot pod is on standby and ready to send data (like the heart rate monitor).
After 30 minutes of inactivity, the foot pod powers off to conserve the battery. When the battery is low, a message appears on your device. Approximately five hours of battery life remain.
Information on How to Pair Several Watches with Stryd:
http://fellrnr.com/wiki/Stryd
Stryd’s explanation on when GPS/footpod/accelerometer is choosen:
https://club.stryd.com/t/stryd-foot-pod-does-it-need-a-calibration-factor/3517/971
Stryd’s How to Pair for Garmin Watches:
https://support.stryd.com/hc/en-us/sections/360000206994-Step-3-Connect-with-your-Garmin-Watch
How to Determine What Features Your Watch (or pre-purchase has)
If you are trying to figure out how to setup your watch properly or determine if a watch has the features you want, find the user manual online by search ‘vivoactive HR user manual’, and look for the ANT+ Sensors --> Footpod section, under this section the user manual will go over what features are available. In the examples below you can see the vivoactive HR does not support speed nor distance from footpod, but in the Fenix 5X user manual there is a section of the user manual that goes over setting speed and distance options for the footpod so you can see that you can always get speed (pace) and distance from the footpod instead of GPS if you set those options correctly.
vivoactive HR (does not have auto calibration, nor speed from footpod, nor distance from footpod):https://www8.garmin.com/manuals/webhelp/vivoactivehr/EN-US/GUID-5B7E3136-E4DC-47ED-89EB-60794DCF1408.html
Fenix 5X (does have auto calibration, speed from footpod, and distance from footpod):https://www8.garmin.com/manuals/webhelp/fenix5x/EN-US/GUID-ECD3DF02-17CF-48E7-9B93-FCED901BBB22.html
Other Option: fellrnr.com1 has a list of some current Garmin watches (and others) that shows what data you can and can’t get with a specific watch paired with Stryd:http://fellrnr.com/wiki/Stryd#Using_Stryd_With_Your_Watch1