Today, wearables have become synonymous with fitness. Sporting an Apple Watch or Garmin or other such seems to suggest that the wearer is heavily invested in their fitness and keeps a very close eye on aspects of wellness like sleep, steps, heart-rate and calorie burn. 

The question we raise in this article and as well as in the corresponding podcast is: are wearables essential to maintaining a healthy lifestyle or are their uses merely perceived?

The main driver behind this question is - how much does sleep, steps and calorie burn actually affect a fat loss or weight loss journey? Is the data that the tech gathers useful to the wearer so they can optimise their training?

To understand this better, check out Episode 212 on RNT Fitness Radio where the RNT Team have a conversation to take a closer look at advantages and disadvantages of using this technology 

In the podcast we talk about the three main uses of any of the wearables that are in the market and how they can both positively and negatively impact training. 

1. Sleep

There is a common misconception that suggests poor sleep automatically results in more fat gain over the long term. Mechanistically, the only way a lack of sleep can lead to more fat gain is if you cannot manage the hormonal cascade that follows suit (poor blood glucose regulation, higher stress hormones, less sex hormones) and you end up overeating as a result. 

On top of that, studies have shown that if your quality of sleep is consistently poor, your weight might stay the same but it does result in a poorer body composition, leading to more muscle being burnt in comparison to fat for the same energy deficit. This is one of the reasons why sleep or the lack of it may not have a direct consequence on fat or weight loss but it does affect your weightloss journey indirectly.  

Another very important reason to consider is that when we are tired after a bad night or two of poor sleep our ability to make better decisions suffers. We feel tired so we feel we need to eat more food, we crave for satiety and nothing satisfies that need like a sweet treat, that sudden sugar rush makes us feel energised but only for a few moments, which is why after a few hours we end up feeling worse and now need another pick-me-up: the vicious cycle continues.  

When RNTers start off on their transformation journeys, the wholesome and nutritious food combined with the increase in water intake does result in more frequent trips to the loo at night. This eventuality worries a few members as they find themselves waking up a couple of times at night to pee. But it is not a problem as long as you go straight back to sleep, it becomes a concern if after every trip to the toilet you are lying awake in bed for an hour - then something needs to be done about it. 

How does this all tie into wearable tech? 

The answer is simple - when we use our wearables to track our sleep it gives you data on your REM (Rapid Eye Movement) sleep, light sleep,  deep sleep and time awake. For REM and deep sleep, these can be wildly inaccurate which is why trusting this information can be very tricky. This is because your wearables can register you as sleeping, even if you are just lying still and not moving and then compares this to your heart-rate. When in fact the only way to gauge quality of sleep is by tracking brain waves and monitoring your eye movements during sleep, which your tech isn’t designed to do; not yet at any rate!  

It also calculates Heart Rate Variability (HRV) the fluctuations of time between each heart beat. The higher the variability the better your recovery and the lower your variability the lesser your recovery. Since your tech can’t calculate this accurately it gives you a rough estimate and then tells you if your body has recovered and if you should head to the gym that day or if you should rest. 

The data is so compelling that it often over-rides our own instinct - we may wake up feeling fine but then when our watch or ring tells us we haven’t slept, we trust the tech more than our own body’s signals. If the reading says don’t train we find ourselves looking back over the previous night thinking we haven’t really slept all that well and then decide to take a rest day. Which is detrimental to our fitness journey. 

This is how Ivan, Ed and Akash use training if they aren’t feeling rested:

Ivan: How many times have we headed to the gym, feeling like mud and left with a new PR? 

Akash: Heading to the gym and training when you are feeling tired is actually the best thing you can do as it gives you a boost of energy that can carry you through the day. 

Ed: Training when you feel tired will leave you feeling way more energised than a sugary snack and will keep you on track with your fitness goals. 

Can the data be useful for anything? Yes - it can be! 

Your wearable can tell you how many hours you have slept at night and if it tells you that you have slept for only 5 hours, it gives you the opportunity to look over your routine the previous night. What did you do before you went to bed? Were you working late? Did you eat your dinner a bit too late? What behaviours didn’t benefit you that you can avoid the next time. 

This works brilliantly in the opposite scenario as well. If you had a solid 7-8 hours of sleep and you feel really rested. What practices enabled you to do that? Did you turn off screens an hour before bed? Did you drink enough water during the day? Did you listen to some relaxing music? Whatever you did the previous night can be replicated to ensure you get a good night’s sleep regularly. 

Top Tip 1 

Before you look at the sleep data in the morning, give it your own score and then compare it to the score you see on the device. 

In a very interesting study, 164 undergraduate students were fooled into believing the scientists could actually calculate how much REM (rapid eye movement) each person got. Students were told whether or not they had less than average sleep or better than average sleep based on these sham scores and were then asked to perform a battery of cognitive tests.

Regardless of how each student slept, the scientists found that the students who did the worst were the ones who were told they had a poor night’s sleep. This just goes to show the power of placebo and if your watch has given you a “bad score”, you can easily fall into the same trap as the students in the study.

Top Tip 2 

Never use a sleep tracker to tell you if you are going to train that day. Instead use it to analyse your behaviours and how you can optimise them. 

2) Heart Rate and Calorie Burn 

Another popular use of wearable tech is to track your heart rate while you are active as well as while you are resting. 

Looking at the heart rate readings during exercise can be beneficial if it fuels your excitement and engagement. 

Ed: I started looking at my heart rate monitor and this has actually made me more excited about my cardio. Looking at the graph enables me to work harder in my cardio sessions. 

If the data has this type of positive effect on your training and makes training more enjoyable then it is definitely worth it. 

Where the heart rate sensor can throw you off course is in its energy expenditure predictions. Your wearable calculates the amount of calories you burn using the accelerometer along with the heart rate monitor. The heart rate is monitored by the strobe-like green light that flashes against your skin. Our blood actually absorbs this green light and it measures the pulse based on the feedback it receives: again this isn’t an exact measure.  

The wearable analyses your movement along with your heart-rate and gives you a calorie burn estimate. The trouble is that if you are relatively fit your endurance levels are higher and you may be able to sustain a higher level of activity without it affecting your heart rate. But if you are less fit your heart-rate can go up even with a small amount of exercise. 

Ed: If I compare myself to a professional athlete whilst cycling. I may be cycling at 20km/h while the athlete is cycling at 40 km/h. Both our heart rate readings will be the same, for example 150bpm. But the amount of energy expended by the athlete will be way more than the amount of energy expended by me. 

3) Steps 

Of course the most common use of the wearable is in counting steps. This is a great feature as it keeps you motivated and can result in some friendly competition to see who can total up more steps in a day. 

But of course there are less expensive ways to track steps, most smart phones come with this handy feature. So you probably don’t need an expensive device to tell you how many steps you’ve taken throughout the day. 

Bottom Line 

If you are on a body transformation journey then the data that is presented to you doesn’t have a lot of value. In fact the data can overwhelm and leave you drowning in data that you can’t really use. 

However, If you are doing everything and you are really looking for the small bits to see how you can improve and optimise your routine it can be useful. 

Ivan - So if you have a wearable and you enjoy it, see how you can use the data to guide you in the direction you want to go without leading you down a track that is not based on proper scientific evidence. 

Akash - Just remember what you are doing it for and make sure it’s working for you and you aren’t reading too much into the details. 

Ep. 212 - Should You Use Wearable Tech?

Ep. 212 - Should You Use Wearable Tech?