I have been obsessed with wearables and their ability to provide a better look at recovery, recovery readiness and energy systems for a little over a year now.
My obsession started with my training for Trail Fest, which was a three- day trail run through Bryce Canyon, Zion, and Horseshoe Bend, each night was spent sleeping in a tent and each day was spent navigating roughly 10-13 miles of elevation, and various terrain. Trail Fest training presented several challenges for me: how to recover in a short period of time, how to push regardless of said recovery, and doing a sport I had never done before.
First and foremost, I had never trail ran, and although I found trail running exhilarating; your brain is constantly engaged making decisions as to where to plant your next foot step as you navigate rocks, mud, and various terrain and how to navigate uphill and downhill; it was EXHAUSTING! Trying to figure out the right shoes, hydration and energy before, during and after the runs and fitting my regular weight training….was challenging.
I bought several pairs of shoes and this is a whole other blog post. Shoes are drama! Hydration - enter Hydrate and Recover by Wilderness Athlete –I slobber all over this product because it is amazing, it tastes great, has minimal sugar and a boat load of minerals, salt and BCAAs.
I struggled with recovery, I wanted to continue to lift weights but my legs, specifically my feet and calves were brutalized each run and when I would do Olympic lifts I didn’t seem to have any explosiveness and well….that’s how you do Oly lifts…with explosiveness.
I started paying more and more attention to the data my Apple Watch, which up to this point my Apple Watch let me know when someone was calling or texting me, and I could play music without having my phone on my person. I started out simply tracking the actual runs (and run is a loose term….there was a lot of walking) I was doing. Looking at the elevation, my pace, my heart rate, although at this point the only thing heart rate meant to me was the higher the better, as it showed I burned more calories during these sessions. Up to this point burning more calories meant a more fruitful training session! Ooooffff, so cringe-worthy.
Enter in a random podcast I hear about Heart Rate Variability (HRV). And a whole new plethora of information was born to me. I was obsessed with my HRV – the higher the better. And with Apple Watch, before the upgrade, you could game your HRV with the Mindfulness App. You’d do a 60 second breathing meditation and it would give you your HRV reading. While you sat there in a near state of slumber your HRV would (most of the time) climb. And this would make me feel accomplished…this would make me feel…perfect. And secretly we are all dying to be perfect and surprisingly we are all actually dying…not today, but that is how this journey ends.
I venture into HRV pandemonium…and I am not joking. If you were in my life from April, 2021 until recent you had to listen to me talk ad nausea about HRV. I am going to give you the real abbreviated version: HRV is the amount of time in between heartbeats, theoretically, higher the number the stronger your resilience. However, us being crazy biological creatures nothing is that simple. Tracking HRV is complicated to start; the best reading being first thing in the morning when you wake up, a 5-minute reading while you lay completely still.
Wearables use Optical Heart Rate Monitoring (OHRM) a method called photoplethysmography (PPG)…yikes on those big words, right?
PPG is a technical term meaning “shines light into your skin and measures the amount of light that is scattered by blood flow”. I am really watering down this process but I might have already lost you, so I’m trying to keep this simple. Theoretically when light enters the body it will scatter in a predictable patter as the blood flow dynamics change, as such with blood pulse rates and blood volume (heart rate and blood pressure). How does it work? No one really cares…so I’ll save you the pain. However, these patterns are based of metrics of population. What does THAT mean? That means all patterns – my pattern a 44 year old woman, at 5’5” weighing 132#s with body fat of 18 percent with relatively good fitness is measured against a 6’4”, 28 year old male with a body weight of 185#s and body fat percent of 12 percent and even better fitness and a 300# man who is 50 years old with a body fat of 50 percent and no fitness capacity. AND surprisingly….HRV is hardest to read in athletes and sick people….go figure.
Wearables use heart rate focused technology that is generally run through several algorithms based on activity types – these are activities with known Metabolic Equivalent of Task (MET) scores that are then fine tuned with user input data (height, weight, age, maximum heart rate, etc) other sensor data (temperature, elevation) and derived user data (VO2 Max, respiration rate). Things that impede data: accurate maximum heart rate for activity (we about to get into that), body weight (make sure you keep this up-to-date in your wearable…it matters!), and sensor connections (frequent drop outs, Apple is famous for this).
MET calculations is equated to population norms – not YOUR norms. Heart rate data is extremely prone to external influence, use of stimulants (caffeine, pre-workouts) prescriptions (beta-blockers, weight loss pills, hormone therapies, etc) drugs (alcohol, THC, etc), metnal stress, sleep status can affect your readings.
Soooooooo…..is the data the wearable providing garbage? Well yes, and no. Nothing can ever be simple when it comes to us biological creatures – which is why fitness and exercise science although infantile to medicine science, should be treated exactly the same….carefully and with someone who is educated AND experienced.
I recently switched from my trusty Apple Watch that I had for four years, and was familiar with interface and had a bunch of fancy apps for sleep and HRV and Heart Rate Zones downloaded to a Polar Vantage M2 that has a completely different interface. I immediately started to notice stark contrasts in data.
First was step counting. I roughly do the same activities each day, so I know on a Monday-Wednesday I am taking about 12K steps, on Thursday I become a slug (I don’t coach) and only get about 8K steps. So when I was at 15K steps at 3pm on Monday I raised an eyebrow. Did this mean Apple was stingy with the steps or Polar was abundant? Polar tracks movement, so when I gesticulate and talk (this means I flail my hands around a lot when I talk….I’m an animated mother fawker, I have a great impression of a fruit fly….please don’t hesitate to ask to see it) I’m accumulating steps even though I’m only flailing in place….but movement is movement? I really don’t have a good answer for this.
I next noticed my heart rate didn’t get quite as high on my Polar watch as it did with Apple. Polar is a cardio based fitness watch. It has a Cardio Trimp load based application – and as best I can tell this means in the world of Polar cardio based workouts that are longer then 20 minutes are king, everything else is…well everything else.
The piece of the Polar data that had me filling out a return form, and talking to anyone who would listen to me try and work through the wickets of what I actually needed/wanted in a wearable was the readiness score. Polar was consistently telling me I was in “Maintaining” mode with my training through the week – and this would infuriate me, I train hard, I’m exhausted (like taking a nap mid-day) and can feel I am being too taxing on my energy system and this ballsy bitch on my wrist is like….MAINTAINING…..
After about three days of discussing this and researching it (I literally had to charge my phone 3 times a day I was spending so much time looking anything and everything I could find on this up)…..I’ve come to the conclusion….I don’t give a fuck what my readiness score on my Polar says or what it had said on the Apple. I’ve rocked and rolled around in this body long enough to know what is going on. With the Apple Watch I used the app Training Today; and it would tell me I was a 1 out of 10 and I would train, or not…the data didn’t impact training decisions.
Alright…what do we do to help determine recovery, readiness and use our energy system smartly? Do we throw these wearables in the trash? Save our money and never buy one? What??
I asked myself this question just last night. Did I spend $200 on this Polar watch for nothing? I’ve come up with: no. I like when I go for a run, hike or bike ride knowing how far I have gone, and my pace, so a device with GPS is needed. I like knowing my heart rate during a workout and I like having the visual graph of how my body responded to the stress. But to use the data for recovery and readiness I need to establish my own maximum heart rate.
Wait…Ange, did you just say ESTABLISH YOUR OWN MAXIMUM HEART RATE…..ooooffff..
Yea I know….ooooof is right? Well let’s take a look at WHY….and yea, I’m so sorry…this is my first blog post back at it and this is so technical and boring…..but I know the people who want to know this information will appreciate it. If you aren’t into recovery, readiness or use of your energy system this will be of little interest to you – stay tune, I will make a blog about something you do find interesting!
Why you don’t want to use the standard maximum heart rate formula. The standard maximum heart rate formula is 220 minus your age (IE. Mine would be: 220-44=176) . This is a SIMPLE formula and it was established in the early 80’s…I think 1982, but don’t hold me to that, and it is based off of a population wide meta-analysis – which means people of all sizes, ages, races, fitness capacities, prescription taking, medication using people – the ENTIRE groups median was taken to establish a “good guideline” for maximum heart rate.
68 percent of the people in the median fell within this standard range of 200-age, BUT……plus or minus 10 bpm!!! And the other 32 percent fell completely out of the range.
You don’t have to be a scientist to know that 32 percent inefficiency means…trash data.
Age and fitness status matter. Younger athletes with a greater fitness capacity can have lower maximum heart rates, and older athletes can have a higher maximum heart rate, and both are normal. But if you go with a 20 year old, there maximum heart rate could be 200 bpm, but that same 20 year old could be an endurance athlete and there actual maximum heart rate is 170. You can have a very fit 45 year old and the 220-45=175bpm maximum heart rate, but this athlete can easily see 195bpm without distress. Facts matter.
And a plus or minus 10bpm is a BIG DEAL! If you have ever done zone training you know 10 bpm can easily determine an entirely different zone. Which let’s be honest, if you don’t train in Zone 3 as the program prescribes will you die? No..at least not for non-compliance of the programming (let’s re-establish we are all going to die…the last two years have reminded me I need to remind everyone they are going to die…there is no bulletproofing yourself from death, you CAN ensure the ride is a little less….hospital spent to a large degree..but you’re going to die.)
Let’s be real honest here – we don’t need to know, we like to know. Because again recovery, readiness and using our energy systems wisely MATTERS….a lot.
So we determine our OWN heart rate maximums. But again….we biological creatures can’t be simple. We actually have to determine our maximum heart rate zones for different modalities. Le sigh….I know…I know. I felt the same way…but then I also got excited because….data.
I highly recommend you do your own maximum heart rate test for each modality (running, weight training, cross training, cycling, etc). My heart rate differs drastically when I run to when I lift weights, it is on the higher end, in my typical Zone 4 for running and when I lift weights I stay in Zone 1, even when pushing heavier weight loads.
Keep track of these numbers and you can change them manually in your device. This will help you create accurate reports of your activity, ranging from more accurate calorie numbers, and workload. And you can track calories consumed in a separate app – I still do this and I can tell you the macros of just about any food. It’s just good “math” to add up how much you are consuming – we live in a plethora and it is easy – especially if you train a lot in zone 4 to over eat.
Nowhere (yet) can a wearable measure the load weight training puts on your body. Weight Training does not have a fixed load like running (where every repetition (step) is essentially the same) and heart rate is a poor proxy for output on weight training. Wearables, to date, cannot accumulate Central Nervous System (CNS) fatigue. What is CNS fatigue? It is loosely defined as the brain’s inability to actually send sufficient signals to allow for full (or nearly full) activation of the motor neurons. If the signal for motor neurons is reduced or the motor neurons themselves becomes less responsive this is considered CNS fatigue. In layman’s terms the athlete has an inability or reduced capability to create maximum tension, and a reduced ability to perform explosive/high skill movements. This is why sometimes you can pick weight up effortlessly and sometimes it is glued to the floor.
How do you predict CNS fatigue? Unfortunately, you don’t, it is generally one of those things where you start lifting and everything feels heavy. And your emotional feelings have nothing to do with your CNS. There have been many days I haven’t felt like training – felt fatigued and drained – and was able to push big loads. CNS fatigue is very different to peripheral fatigue.
EEEP….this was so long. I’m going to end this….If you have questions!! Please ask! I’m passionate about helping everyone workout in ways they love, and find stimulating….without killing them faster, or making them a useless person in their real life. Energy systems matter! Exercise enhances life – it isn’t life, unless you are a professional athlete.
Until the next time….keep moving, and eat your veggies.
