Training

WHEN THINGS GO WAY WRONG

Post x-ray it was clear it was game over for the season and its not so much the injury but the 8 months work to get me to Kalmar in top shape that’s so hard to swallow.

 

It’s been a while since I posted and that’s because I have been licking my wounds. 2018 has been a real mixed bag. I took a big chunk of the year to improve my bike and bike to run and with a new coach and whole new focus on hard training. The aim for the year was Ironman Kalmar and to qualify for Kona and get my times down towards 9Hrs.

The year started off well with a best time at Outlaw Half Nottingham then a good race on the mental side at IM 70.3 Switzerland (when things don’t go to plan can you push). However, in the building up to IM Kalmar and on my last long training ride I came of my TT bike and broke my clavicle & damaged rotator cuff. That’s not to mention the usual general battering and bruises – but at least the bike was OK ha.

Figure 1. Me immediately post crash battered, bruised and collar bone snapped. Then post operation to removal of bandages and stitches.

Figure 1. Me immediately post crash battered, bruised and collar bone snapped. Then post operation to removal of bandages and stitches.

 

Post x-ray it was clear it was game over for the season and its not so much the injury but the 8 months work to get me to Kalmar in top shape that’s so hard to swallow. I was just about recovered from a van hitting me on a training ride from the year; so to be injured again on the bike was a real downer. The biggest issue is the time spent getting back to health and in shape to give it my all at Kalmar that was so hard to swallow.

I have to say I had to consider that having 2 accidents resulting in a broken back in 2017 and broken collarbone in 2018 should I continue on. While that thought spun around in my mind I jumped back on the bike a few days post injury by rigging up a harness from my TRX. I though I could train as long as I didn’t have hold the bars of my road bike and the harness around the chest allowed me to avoid putting any weight through my arm and broken clavicle. I had some great advice including some from the ever winning Lucy Gossage which gave me some confidence in keeping active despite the damage.

I only trained 3 times a week over the 1stfew weeks but after the 1stweek all sessions where short but high intensity. I figured if I could hold onto some of the gains when it came to making a decision of continuing on with Kona / sub 9HR dream then I would have some fitness as a base from some maintenance work.

 

THE DECISION

The last 3 years I have worked hard to improve my performance and in 2018 I had bumped up the weekly training to circa 15Hrs from 10Hrs the years before. The idea of giving up on that work, time away from the family, early morning and late training nights just stuck in my throat if I was just to quit.

As you guys will know family is everything when we do this crazy sport and I am very lucky to have a really supportive wife and a daughter who loves to see her dad race (It’s a free holiday so what’s not to love).

My motto has been to ‘Never Quit’ and this is painted on my pain cave wall. The other issue was if I gave up on the Ironman dream could I really just let it go without regrets?

Once I had made the decision to give it another year it was a case of getting some races booked in so that a real focus could be brought back to training. Then to go back to the coach to get a program back in place.

 

GETTING BACK TO TRAINING

After 6 weeks post operation (break pinned and plated) I had a follow up x-ray which showed it still was not fully healed but I could run but no swimming. My final follow up will be next week (1st week November) and I should then have the all clear for swimming.

Over the past 4-5 weeks I have managed to get back running up to 21km on long run at around 4.20Min/km and my bike has become the strongest to date. The latter has been as a result of getting up to 4 session in a week and all hard sessions around threshold. All threshold work, now above 4.2w/kg and feeling strong and attacking each workout.

Like everyone its end of season and time to ease up on the diet. Always tough mentally as you get use to being lean but you need to let the body and importantly the mind unwind following the strain and stressors of the season. The cut off for me should always be around 6-7% of your race weight so you can gradually easy back on the diet and up the training. Those who fall outside of this range typically end up over dieting which results in poor recovery from training session and an increased risk of illness and injury. There is also the psychological issues of cutting back the calories so hard to the point people can break and start binge eating.

Its now November and it’s the start of the next season of ‘structured’ training for me building to a half marathon in Feb. The marathon is no more than a target to keep me honest over the xmas period as I start to tidy up the diet.  The next triathlon will be Challenge Salou in April and the ‘A’ race in September. Fingers crossed no crashes or white van man this year. With 2 IM distance events booked for 2019 I am hedging my bets I make at least one in good form without injury.

So guys have a great xmas, keep safe if your out on those roads and all the best for 2019!

The Myth of Functional Threshold Power (FTP)

“If you repeat something long enough people will begin to believe it’s the truth.”

 

 

How can I set training zones based on power? Are they accurate? Are they based on evidence? These are just some of the basic questions those looking to base their training on power. One of the most widely used and accepted methods of setting up training zones are based on what is know as the “Functional Threshold Power (FTP) test”. We see it used by coaches, listed in the magazines, and now it’s proliferated into online virtual training platforms and virtual reality training platforms such as Zwift and TrainerRoad.

However, what is the scientific basis of the FTP test? Does it measure / reflect lactate threshold? What are its limitations? Are there better options? In this blog and want to take a real look into the limitations of this suggested method of setting up a training program and why I believe it’s not all its suggest to be.

*In advance there is a little bit of physiology and some discussion of studies in the following blog. This sometimes breaks up the flow of a discussion but try to stick with it as it should help explain my views on FTP.

**November 2017 BLOG UPDATE: Please see comments and clarification following the publication with Dr Coggan, regarding FTP tests. 

FTP or Critical Power

The basis of FTP and other measures of so-called ‘threshold testing’ is defining that point between energy being primarily supplied by the aerobic system (i.e. sustainable over a long time) and the anaerobic system (sustainable over a short period of time).

According to one of the main academics behind the FTP test; Dr Andrew Coggan[1] states, “FTP is the highest power that a rider can maintain in a quasi-steady state without fatiguing for approximately one hour.” In addition it is suggested that the best predictor of performance is performance itself – so a 60-minute time trial is just that a great predictor of 60 minute time trial. Because 60minutes is often very difficult (especially the relatively untrained) its suggest by Coggan that a 20minute test can be used, which is described as underestimating the 60minute test by 5%. Knowing this the 20minute test is suggested as a means of determining FTP.[2] This is interesting as a description of the test but what is the scientific basis? Why should we use it (or not) to develop training zones?

The underlying basis of the FTP test is touted as being 1. Being representative of lactate threshold (See Figure 1) and, 2. The mathematical concept of critical power (CP). So lets take a look at both of these with reference to the FTP test.

 

Figure 1

Figure 1. Here we see a test of lactate threshold with a subject working and increasing power and lactate levels rising at a relatively low rate until a threshold (LT) is reached where any additional increase in power output results in an almost exponential increase in lactate.[From Coggan AR. Training and racing using a power meter: an introduction. 2003. Accessed online at: www.ipmultisport.com/ref_lib/Coggan_Power_Meter.pdf].

 

Lactate threshold and FTP

One of the main studies cited as supportive of the 60minute FTP test as being reflective of lactate threshold and a pragmatic approach to non-lab based testing is that by Coyle et al. [3] In this study 14 male endurance athletes where used. The cycling lactate threshold test was based on testing at 5 different intensities and looked for a 1mmol (a blood measure of lactate) change on blood lactate above baseline as representing the balance between lactate production and use.

The performance test was cycling until fatigue at 88% of maximum (Vo2max). The study split the group into 2. One group (HL) that could work at a higher % of the maximum at lactate threshold (72-86%) and one at lower level (LL) (59-71%). The results in terms of time to fatigue for the LL group (working at 34% above threshold) and the HL (3% below threshold) was as follows.

Time to fatigue in the HL group was 60mins and the LL was 29mins.

Therefore, how can was state that a 60 minute FTP performance test can be related to this study and lactate threshold when the LL group did not work at lactate threshold but 34% above it. Similarly, the HL group although lasting on average 60mins, when we look at individual subjects we have one lasting 75minutes and another only 51minutes be fatigue. That’s a possible variation of 24Minutes between subjects? As such we cannot base any type of assumption that the FTP test is reflective of any type of late threshold based on the results of this study.

Given that subjects during the test where not aware of the elapsed time this perhaps speaks of the inherent variability and weakness of the FTP test i.e. how motivated are you to perform? When the real question is when does lactate threshold occur.

Therefore, I am not convinced that a 60minute test can predict accurately where the lactate threshold is or power at lactate threshold (or at least not without possible significant variability). Although there is no doubt a relationship between Lactate threshold and time to exhaustion that does not mean that time to exhaustion or max power produced over 60 minutes is an accurate value to determine training zones.

 

The concept of critical power (CP)

The critical power (CP) test was the mathematical basis of FTP in many ways but it when we look at what the CP test involves it not merely a 20 or 60minute performance test.

The relationship between power output and fatigue was initially introduced by Hill (1927).[4] However, it was Monod and Scherrer (1965)[5] that coined the term ‘Critical power’. These researchers investigated the relationship between power output and time to exhaustion during multiple bouts of exercise on specific, isolated muscle groups. They then derived a mathematical equation that defined the relationship between power output and time to fatigue. This test involved 4 -5 bouts over a time period of 2 – 24 minutes and the data then entered into the equation to define CP.

We can already see limitations to this work – as they say ‘no muscle is an island’ as such testing a single muscle group would not be reflective of the physiological stress brought about during cycling where we see modern day application of FTP. So what about looking at a more relevant studies.

One of the primary papers referenced as underpinning the suggestion that CP is representative of maximum lactate steady state (MLSS)(i.e. just below lactate threshold where there is a balance between the rate of lactate production and the rate of lactate removal primarily representing aerobic system) or just above it is that by Poole et al.[6] In this trial a cycling test was used to assess the relationship between power and MLSS. Similarly, we see other studies referenced to demonstrate a relationship.[7]

 However, although there maybe a relationship that does not mean accurate. For example I might say driving when the group is icy may result in a 60% chance of a crash but 60% although significant does not predict it will happen. In assessing the accuracy of such a relationship last year Maturana and collegues[8] demonstrate that CP (calculated in tests over 1-20mins) over-estimated MLSS by 20w (based on subjects with a threshold of about 255w). That’s an 8% overestimation and although it may not sound like much if you cycle 20w above MLSS it will result in a continual rise in blood lactate ending in subjects fatiguing before the end of the test.[9] These results have been further repeated by studies from the likes of Bull et al, which demonstrated that CP overestimates the power output that can be maintained over 60minutes. [10]

Finally, the calculation of CP is highly impacted by the mathematics employed to identify CP, as is training status of subjects and pedalling frequency (higher cadence resulting in lower CP and FTP).[11]

As such this general view amongst people that CP and FTP are representative of lactate threshold is clearly flawed and at best controversial among scientists. Therefore, care should be taken to base any type of training program on the basis that FTP or CP is an accurate representation of an athlete’s true threshold.

 

What else does FTP testing not tell us as athletes?

An important factor in developing an effective training program is to know what our physiological strengths and weakness are. As part of determining where there are weaknesses we need to look at factors such as aerobic or anaerobic capacity, or economic an athlete maybe (the oxygen cost of cycling at certain intensities). What we get from FTP testing is one value, ‘a performance measure over one hour’. We do not get a measure of oxygen cost (or oxygen cost per watt – economy), lactate threshold, or similar measures that are independent of psychological motivation to complete a test to full exhaustion. In fact in most lab-based test of aerobic capacity most can generate a value well before physical exhaustion.

Another important factor is the assessment of fuel use across a given range of exercise intensities. What I mean by this is how much fat (grams/min) and carbs (grams/min) are you burning to maintain a given effort (say 200w vs. 250w). You may ask why is this important?

Well for any event exceeding 2.5-3hours in duration it can be massively important as the results from sub-maximal and max testing can give and indication of how much carbs we would need to take on board (based on stored carbs or circa 400-500g) to get us through an event. For Ironman based events such information can be vital to effectively determine pacing and nutritional (Carb) intake requirements.

So what about the practicalities of getting testing carried out in a lab (no I don’t do such testing)? A submax (check of bodies response to aerobic up to threshold work), max (anaerobic capacity and maximum oxygen uptake), and LT test carried out for cycling and running may cost in the region of £300-400 in the UK. For cyclists only needed a bike test or runners needing a run test its going to be half this cost. When you think about the money spent on a new wheel, helmet or the latest watch such costs spread over the course of a year should not break the bank for most. The data from such testing should not be under estimated and can be massively important in tracking fitness but more importantly identifying how a training program should be structured and how much time dedicated to base, build and comp specific periods.

 

Conclusions

So whilst testing FTP are great as a performance measure and I do believe performance is the best measure of performance its limited as a tool for accurately setting up training zones. However, few of us compete in only 20minute time trials or even 60-minute time trial. As such I would rather base my performance on a performance trial that is closer to what I would experience in a race. The problem is I do Ironman and other than jumping into a half Ironman I don’t thing any performance test would be appropriate.

FTP repeated over time can help be a measure of improvement in fitness/ performance once any learning effects are overcome (i.e. the first time you do an FTP test you may go out to hard and burn out, the next time you will pace better, spreading the effort over the 20mins). However, what I am discussing in the blog is the data in the scientific literature. Maybe tomorrow a new study will find some other reason why the FTP 20 Min test is accurate as a measure of threshold, however, until I see that evidence I can only base my views of what I have read so far.

For setting training zones I want to know how my body is reacting internally – so how much oxygen, carbs, fat am I using at given intensity (heart rate, power, or velocity) and how much lactate I am producing. Psychologically, I cannot significantly control my lactate response of the amount of oxygen my muscle consume for a given power, yet I can control how hard I feel I am pushing for the FTP test.

I am sure many coaches would swear that FTP is a great way to monitor athletes and set up training zones but is this because they don’t have access to other forms of testing? Is it because FTP is quick and easy, needing limited equipment? Have they actually looked at the other options? The bro-science response well my athlete did x or qualified for Y using FTP is not a response to the limitations discussed above. Maybe if they used other ways to set up training their athletes would have achieved their goals earlier, or perhaps many of their athletes don’t achieve but they just pull out those that have as a defence.

In conclusion FTP has its limitations and if it works for you as a coach or athlete and you improving year on year then keep on using it. However, don’t do it blindly, always consider why you are doing something what are the limitations? Is it based on real evidence? I will in later blogs look at the other measure I mention above such as lactate threshold, Vo2max etc but for now I hope you find this blog useful.

Keep training and best of luck for 2017!

Ps. I asked some of the key authors behind the FTP test for comment on what I feel are the limitation before writing this blog but received no response.

 

References

  1. Hunter A, Coggan A. (2006) Training and racing with a power meter. VeloPress, Colorado USA.
  2. Ibid, pg.51
  3. Coyle EF, Coggan AR, Hopper MK, Walters TJ. Determinants of endurance in well-trained cyclists. J. Appl. Physiol. 64:2622-2630, 1988.
  4. Hill AV (1927). Speed and energy requirement. In Muscular Movement in Man, pp. 41–44. McGraw-Hill, New York.
  5. Monod H & Scherrer J (1965). The work capacity of a synergic muscular group. Ergonomics 8, 329–338.
  6. Poole DC, Ward SA, Whipp BJ. The effects of training on the metabolic and respiratory profile of high-intensity cycle ergometer exercise. Eur J Appl Physiol. 1990;59:421–9.
  7. Pringle JSM, Jones AM. Maximal lactate steady state, critical power and EMG during cycling. Eur J Appl Physiol. 2002;88:214–26.
  8. Maturana FM, Keir DA, McLay KM, Maurias JM. Can measures of critical power precisely estimate the maximal metabolic steady-state? Appl Physiol Nutr Metab. 2016; 41: 1197–1203
  9. Ibid n8, pg 218, 222
  10. Bull AJ, Housh TJ, Johnson GO, Perry SR. Effect of mathematical modeling on the estimation of critical power. Med Sci Sport & Ex. 2000; 32 (2), 526–530
  11. Barker T, Poole DC, Nobel ML, Barstow TJ. Human critical power – oxygen uptake relationship at different pedaling frequencies. Exp Physiol 91 (3), 621-632.

Stryd® – Running with power!

There is great potential for power as a running metric but a number of issues to consider before applying it in everyday training.

 

Price: $199 (circa £159.90)

Purpose: Power monitor for running

Website: www.stryd.com [Stry Gen II ‘FOOT POD’]

Summary –      Pros:    Accurate, repeatable, syncs with training peaks /    Cons:  Lack of ability to select specific metrics in IQ stryd watch app / No effective integration of run-power into WKO4

The use of power as a metric for measuring the impact of training and as a tool for optimising performance has revolutionised cycling. However, beyond real time GPS little has changed beyond measuring heart rate from the late 70s and early 80s. This may just have changed with the introduction of power measurement for runners. One version of power meters for running making the headlines has been ‘Stryd®’. I have being playing about with the Stryd over the past few weeks and thought I would share a few findings thus far.

Screen Shot 2017-02-09 at 13.53.20

Figure 1. Photos of the Stryd. Super small & light-weight!

 

Benefits of power for running

Many of you will already be using power for cycling but the application to running has some significant differences –  for example in cycling the more power you put through the pedals the faster you go. However, in running you could theoretically have increases in power but no increase in speed, but why? The simple reason is you’re locked into a certain position on a bike and the measurement of power simply represents what goes into the power meter via the pedals. This is very different during running as we use power ideally fwd motion, but as you know when we run we move up and down and side to side. All of this non forward movement could result in a loss of forward propulsion from our power production. The take-home not all power results in fwd movement.

Therefore, the Stryd could be a great tool in  assessing the point at which power peaks in faster running and at what point any additional power does not further increase speed.

 

This type of data can provide guidance in technique development by helping modify our form so that any wasted power (excessive up and down and side to side) can be corrected to result in better fwds movement.

So from a personal point of view I have used cadence on Garmin’s to be more economical in my running. However,  I did not know how to ‘effectively’ apply form changes to impact other metrics such as ground contact time (GCT), vertical oscillation (VO), stride length (SL), vertical ratio (VR) that then show up as faster running or faster running for less effort (thats the goal right!).

Sometime to much information can be damaging if you cannot find a practical home for it. I am all about practical application rather than just measuring something because we can. To that end lets have a look at the Stryd and how we can use it at a practical level.

 

How Stryd Works?

In essence the Stryd works using 3-dimensional accelerometer and some clever algorithms to estimate power production. According to the Stryd team the product and its data has then been then validated against force plate embedded treadmill in a lab (gold standard of directly measuring force/power).

As such Stryd can measure force production in 3 dimensions (up and down, sided to side and forwards and backwards). This is at a theoretical level is superb as with the right software to extract the data you could not only look at the metrics we see currently on the likes of Garmin 920xt but also some other metrics such as ‘breaking’ during running (something you get if you’re a heal toe runner). Therefore, the Stryd could be an affordable micro-biomechanics lab that could be used not only to measure power (next section) but also to monitor and manipulate in real time, running economy and form (#Free Speed).

 

Power measurement and running

I have to say this blog has been a bit delayed because I have had in my possession the Stryd for a few months. However, I wanted to have a play about with the stryd in multiple conditions and paces (Intervals vs long runs etc etc) to see what it can and cannot do. Being from a wet and windy part of the UK this has made for a challenge when it comes to finding a dry and non-windy day.

There are a few metrics that are a must have for me when running – pace, heart rate, distance and time. As a new bonus power is now a possible ‘new’ metric to add to that list.

 

The Stryd App

At present there are 2 apps available for Stryd when using watches such as Garmins 920xt or similar. These can be accessed by the IQ connect and include:

  • Stryd IQ (official app)
  • Stryd 10s power (non-official / unsupported app)

Then we have additional ways to see the data when using and for post analysis:

  • The stryd app for your phone (during running on a treadmill)
  • The stryd online power centre (post run data analysis)

I have had a play with all of these and the phone is nice if you want to see a big screen whilst in the gym, but on the road is not practical. So I will focus on those ‘other’ apps and the data given from the watch displays and via Stryd’s own website ‘the power centre’.

Before that I want to just give a quick overview of some metrics you can get from the Stryd outside of those typically available with a Garmin such as cadence, hr, vertical oscillation, ground contact time etc.

  • Power: The stryd records real-time (instantaneous power) however, there is a workaround app to give 10s average as discussed below.
  • Leg Spring Stiffness: Based on variance in ground contact times (typically less ground contact means running faster and to a point more economically). In general we see swimmers having very flexible ankle (not stiff) and as such transitioning from swimmer to runner is harder.
  • Form Power: This is the power to raise one’s centre of mass against gravity with each step and is independent of speed and gradient. The application of this is when your form (body position etc) is altered to decrease this number is associated with improved economy and reduced vertical oscillation.

 

My testing of the Stryd

To look at the way the Sytrd works I wanted to check out a few different types of sessions that are typical for most runner and triathlete training sessions. These are the long run (outside) and intervals (treadmill). These are a nice mix of sessions on different surfaces and should be able to highlight the pros and cons from using the Stryd and its related software.

Before we start using the Styd we need to find out our training zones. For me these are carried out during a lactate threshold test (see previous blog on BSx). From that test set training zones are based on Hr, Pace and Power.

 

The Power Centre: Analysis (Pro’s and Cons)

The 1st session was intervals (warm up, then 3 x 11Min reps at 3.45/3.45 min/km or 6.15min/mile if you like imperial). As you can see below (Figure 2) we get some nice square wave power level shapes (orange line) for each fo the 3 intervals. When doing bike intervals and using a power meter these shapes are very similar, and like using power on a bike we can see a lag in the heart rate (purple line) getting up to 160bpm (the goal pace for mid to upper Level 3 work).

pc 1

Figure 2: Stryd’s online power centre – Data analysis from Interval training on a treadmill.

 

The lag in Heart Rate for me was about 5-6 mins before hitting what would be level-3, therefore power allows us to instantly work in the right zone rather than consistently upping or lowering pace until you hit the right the heart rate. However, it could be said why not just set our training zones off pace as that’s a way to cut out the delay (lag) in heart rate rising to the hight level?

Well again we have external issues than can increase or decrease the physiological demand (effort) of maintaining a specific pace. Pace does not take into consideration the effort it might take to get up or down a hill or running into a head wind. What’s great is that (theoretically) using power would make issues as weather (wind) and terrain (hills) irrelevant to a large degree – resulting in consistently hitting the right training zone in every session.

pc 2

Figure 2: Stryd’s online power centre – Data analysis from easy long run!

 

The figure above shows some metrics from a very easy zone 2 run and from it you can see the blue line showing pace (min/km) and its nice and steady and tracks closely with orange line (power) below.

At present what I don’t like from using the Stryd is the variability. The power measurement (see the orange line above) is taken in real time. As such its readings of power jumps quite often (unlike the trace we get on a treadmill – see orange line on Figure x) as power can fluctuate from second to second. The result is constantly checking your watch to try and stay in the right power zone. This is not great and a distraction when it comes to pacing a workout on the road.

The solution to this would be to have the ability to see and average of power measurements over say 5-10 seconds as we can do with power as measured using a Garmin on our bikes or like average pace on a watch. The averaging effect would smooth the values (variability) you see on your watch, making running at a constant power more achievable and less stressful. I will discuss the possibility of a workaround for this in the ‘Watch App’ section below.

PC3

Figure 3: Stryd’s power centre – Lots of metrics available on the power centre for data freaks.

 

When you use the power centre there are a whole host of data fields that can be looked at (See Figure 3 above). But for my own view there are only a few that seem of interest at this time. ‘Form power’ (see the ‘Stryd app’ section above for what this metric means) and ‘cadence’ are the main 2 beyond power.

When you run (On a treadmill) is easier to keep a check on ‘form power’ during the session. My view is that keeping form power low is typically due to leg turnover (cadence) and also how you toe-off when running. It provides some pretty quick feedback and typically as form power drops you will also see the power to maintain a set speed falls (more efficient?).

What I cannot say is how this metric is useful across a range of abilities. For myself whilst I don’t have a very high VO2max, my running economy is very good as is my cadence. Therefore, I do not see a huge benefit for an economic runner. However, in others I see run cadence a major issue in them becoming more economic. Many can achieve high (>180) cadence figures when running at 5-10k pace but this drops of significantly as the distance increases and pace drops. I believe that truly economic runners with good form will hold a cadence of circa 180 almost irrespective of run pace (recovery vs. marathon).

As such I see some nice options from the metrics but outside of ‘form powder’ and ‘cadence’ I think they are just nice metrics to perhaps compare overtime (something you can do in the power centre i.e. compare metrics from one workout against the same workout a few weeks later).

 

 The watch app

The biggest downfall of the Stryd is the watch app. The primary App is available from the GARMIN connect store (Stryd IQ). The app allows you to download the data post run to the power centre and also to training peaks. the issue is that there is no ability to decide what metrics you can see on each data field. You simply have to accept the data fields the app allows you to see with power.

watch app

Figure 4: Watch metrics – well at least the useful ones!

 

You also cannot alter the sampling rate for power i.e. per 3, 10, 30 Seconds etc. As above this causes some issues. There is a workaround for those wanting average power and that’s in the form of an app from the Garmin Connect IQ store called ‘Avg Power 10s’. This is the metric I now use on my runs but unfortunately it does not record the power data from that session – so although you can see the data field during the run (average 10s power) and your other chosen metrics such as heart rate and pace etc its not downloadable. It’s also not supported by Stryd.

https://apps.garmin.com/en-IE/apps/ae28e863-89d6-408c-b4a6-94a1683aec7e;jsessionid=A8BF8154DDBF09E083FF08EEB10F970A

 

Is it fit for purpose: Future proofing?

There is great potential for using power for run training and racing but there are still some significant issues to be resolved. I live in the north of the UK and we can get some real windy days and the effort to run in side winds are not fully transferred into the Stryds power measurements in my experience. As such to measure physiological effort in such conditions you need to fall back to heart rate.

However, in days where wind is below 10mph the Styrd is spot on in its accuracy and reproducibility. You can set you training zones using the stryd but take care on what surface. You will get different readings depending on the surface you run on. In my own testing the harder the surface the higher the power recorded. From one treadmill to another despite the same gradient and speed there is circa a 10w difference. Therefore, you will need to build in this when considering your training zones and perhaps power to use if for a race on the road vs. off-road / x-county.

The app needs a major makeover – its very ridged and at this time its not very intuitive in setting it up. What you want is the ability to connect to Stryd as you would a heart rate monitor and for your Garmin to know that and then you have in the field data options all the potential metrics available. Metrics such as those in the power centre plus and ability to look at average power for laps, 5, 10, 30 seconds etc. This will no doubt require more co-operation between Stryd and Garmin and other watch makers.

 

Downloading Data

The final issues relate to training peaks. The only data that gets downloaded is power but no ‘form power’ or ‘LSS’ or similar metrics seen in the Stryd power centre. The other major issue for me personally is the data that shows up as power on training peaks does not sync with WKO4. As such when you want to do some in-depth analysis your cannot use power i.e. the whole point of using the Stryd.

There is also I am sure some other great metrics that you could get from the Stryd but just not accessible ‘yet’. Because it measures 3d power with the right software we could get values related to heal striking (breaking). This would be a valuable metric for helping alter run form and from what I hear from Stryd its something possible for the future.

I know from following the Stryd forums and asking staff about the issues of setting up the app etc that they are trying to resolve these early adopter issues. Similarly, the WKO4 team are working on an update for Stryd but as of yet not timelines have been released.