For the past 18 months, I have been wearing a WHOOP fitness tracker. It’s been a very cool device which I’ve enjoyed wearing. This past weekend, I turned it off. In this post I’m giving the three reasons why – hopefully you will learn something from my experience.
Reason #1: It wasn’t impacting my decisions
Data is only as useful as what we do with it. You can track how many calories you burned at your fitness class, how high your heart rate was, and how much sleep you got – but if you don’t ever change your actions, all of that data is doing nothing but getting these companies multi-billion dollar valuations.
I found that after the first year of wearing the device, I could almost guess my recovery down to the percentage within five or ten minutes of waking up. I knew that if I went to bed thirty minutes later than usual, had two glasses of alcohol, or ate very poorly the day before, my recovery would be low. I also found that if I drank more than two drinks I was always in the red. I learned to plan for these things, and noticed in the last four weeks I stopped checking my recovery all together. I already knew the answer.
Your Takeaway: if you are willing to let a fitness tracker tell you when or if to workout, then using it for recovery purposes can be very beneficial. Additionally, you can hack the system by starting to learn your body’s response to a variety of stimuluses. Start to learn how much sleep you need in order to be in the green zone, what workouts always put you into yellow, and what lifestyle choices get you red. Once you know that, you can move on from your wearable.
Reason #2: Fitness trackers don’t understand resistance training (aka weights)
This isn’t their fault. At this point in time, all fitness trackers are based on heart rate. The technology doesn’t have the ability to read how many micro-tears in your muscle fibers you made during your morning squat session – it only knows how high your heart rate was during your workout.
I was always frustrated by the response from my fitness tracker (WHOOP) after a hard resistance training workout. At Summit, we have a really fun weight lifting class on Saturday mornings, and I love to do that class either during the hour or before, if I am coaching that morning. I would spend 60 minutes lifting heavy weights, and then be told that I basically did nothing. While I recognize that it doesn’t have the ability to understand weight lifting exercises as the same strain level as a cardio-focused workout, this is a really near-sighted view of fitness.
Even many people on the WHOOP podcast, including the guy behind Hugh Jackman and Ryan Reynold’s physiques, recognize that resistance training is a key component of fitness. It is in fact the best way to increase health as we age – yet the fitness tracker was telling me I had essentially done a very low-level workout. While I knew better, it was always frustrating to me.
Your takeaway: If you like hitting the iron more than you like hitting the treadmill, a fitness tracker is essentially worthless. If you have a specific goal like understanding your sleep better, sign up for a six month WHOOP contract and really get into the nitty gritty of how to give yourself a restful night’s sleep. But don’t expect it to tell you anything about the difficulty level of your workout. You will still need to do that yourself.
Reason #3: Fitness trackers are wildly inaccurate
It is so, so tempting to look at my calorie count as the true determinant of how much food I should eat in a given day. Here’s the issue: my calorie counts were always extremely far off. It only got worse the more I wore it, as well, as WHOOP continued to update algorithms. This essentially goes back to my last statement about the inherent bias toward cardio focused exercise. With WHOOP’s latest algorithm update, my heart rate had to be elevated for a specific amount of time before it would indicate an activity had been performed, and then it also gave significantly less calorie-burn credit to different heart rate percentages. This leads to lower strain and therefore, higher recovery. Below, I’ve put two screen grabs – one from July 2019 (before the update) and one from November 2019 (after the update):
As you can see, the strain score across each month is down almost 3 points, and my recovery is up almost 30%. Strain is done on an exponential scale – so that 3 points is significant. I’ll also be totally transparent. I drank and eat significantly more “fun” food than I did in the summer. I trained just as hard. In fact, I’d say our program here at Summit only got more challenging since the summer.
All of this is to say that fitness trackers are wildly inaccurate. Even the good ones, like WHOOP. In fact, according to the current calorie expectation and the amount of food I am eating, I should be gaining approximately four pounds per week. Instead I am losing weight or maintaining weight from week to week. I am not a physical anomaly. I’m eating at or under my calorie expenditure. The fitness tracker is extremely inaccurate in this sense. Again, that is not just WHOOP; that is all of them.
Your Takeaway: Don’t let the fitness tracker tell you how hard you’ve worked, nor how much you should eat. Your coach should be working with you to determine your nutrition plan, and a good coach at this point in time does not come from a piece of technology or a screen. It comes from a human.
Should you buy a fitness tracker?
Like most questions, this is a solid it depends question. I got a fitness tracker because I felt stuck. I was sore a lot, didn’t feel like I was progressing very well, and inherently knew that I was not recovery between my workouts. Functional fitness is a tough exercise plan and I was feeling it. I got the WHOOP strap to teach me about my recovery habits. Now, I’ve figured those out, and while they need some fine tuning, I’ve stopped learning anything from the technology.
This is the way I encourage you to think about your fitness tracker: what problem am I trying to solve? If you cannot identify that, and you just want to have a cool piece of technology on your wrist, go with an Apple Watch. It’s not as accurate nor specific as the WHOOP, but it also does a lot more for less money in the long run.