Why wearables won't kill off the personal trainer...yet

We discover what wearables need to replace drop-and-give-me-twenty trainers
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I wake up 6.30am in the morning thanks to the Jawbone app that's nudged me out of my slumber at the optimum moment in my sleep cycle so I can start the day as fresh as possible.

I pop in some Jabra headphones and the partner Sport Life app checks my heart rate while I watch the BBC News on the iPlayer app on my phone. Fifteen minutes later and I know whether last night's ten mile run has left me too tired to train today.

The orthostatic test I've just done, without leaving the warmth of my bed, tells me my resting heart rate is twelve beats per minute above the average. That's high enough to suggest that I'm at risk of overtraining. A glance at the Polar V800 sports watch on my wrist confirms this. The Recovery Status feature crunches my recent workout heart rate data to estimate that I'll be ready to train again by 5pm that night.


Right now, the best thing I can do is stay under my comfy duvet, not only for another hour's kip, but in doing so I'll also avoid an increased risk of injury. Technology has helped me skip what would otherwise have been wasted time and effort, forcing myself to do an inefficient workout.

But that's just the start of how wearable tech can now act as my personal coach.

Before I've left the house I step onto the Withings Smart Body Analyzer to find that last night's run has helped me drop weight and burned body fat.

I check my food log on my MyFitnessPal to see how yesterday's eating influenced not only the weight the scales are showing me this morning, but also how I felt on the run home and whether I ate sufficient amounts of the right food to aid my recovery.

Then, to help ease the stiffness in my sore calves I strap on some Firefly recovery pads and their electric pulses help flush the lactic acid out of my legs while I eat breakfast. When 5pm arrives, I'll be in better shape to get more out of my training session.

The level of insight wearable and connected technology now provides into how our bodies are performing is increasing at a rapid pace. We're on the cusp of a revolution in the way we get fit and stay healthy. We're starting to have access to tools that give us the power to make decisions about our training that would have been reserved for elite athletes just a few years ago.

Becoming your own personal trainer


So are we all going to become our own coaches? Is this the death of the personal trainer? Can we really tear up our gym memberships and rely on tech to guide us to the perfect body or a personal best?

Technology is certainly moving in that direction. Ever more powerful smartphones, improved low-energy Bluetooth and smaller sensors are increasing the amount of data we can capture but much of the technology we're now seeing is still in its infancy. Accelerometers and stop counting is one thing but we're only just starting to see products emerge that provide a more complete picture.

“I think we're only at the tip of the iceberg," argued Andy Baker, CEO of smart garment manufacturers SmartLife whose innovative sensor technology, built into everyday fashion and sports clothes, will start to capture more of the body's vital signs from breathing rate to body temperature.

“One of the issues is that we haven't got enough data over a long enough period of time. We might currently do a 24-hour heart rate trace every three years. Soon we're going to be able to start doing 365 days a year tracing so you'll be able to see what impact your summer two week break has had on your health and fitness," he added.

“From putting on two units, one on the top half of your body, one on the lower half, we'll be able to look at your heart rate, ECG, respiratory rate and how it impacts on your heart rate. We can also do all the fitness band-style tracking. From your shorts, we can see your muscle twitches, cadence, stride length among other things. So just by connecting your t-shirts and your shorts, we can give you an overall 360 view of your sporting body, in activity or at rest."

Where we might once have sought the advice of a running coach or a personal trainer for these insights, we can now punch in a few details and get a plan that is, at least on the surface, fairly well tailored to our fitness aspirations.

It's here that you could argue personal trainers might have the most to fear but before you ditch you gym membership there's a lot more to consider. Accuracy for a start.

Can we rely on what our tech is telling us?


“Technology is a great tool for monitoring activity whilst it is being done, or analysing data after one has finished," said Giuseppe Minetti, founder of Paleogym, a company that combines sports science and technology with personalised functional fitness and nutrition.

“However, data can be at best within an inaccurate range, or at worst, a guesstimate."

With many of the products on the market using basic information like height, weight and age to estimate things like calorie burn, you can't quite believe everything you read on the screen of the latest fitness band.

A study by researchers from Iowa State University that looked into the accuracy of eight popular fitness trackers backs this up.

Scientists tested a selection of the latest fitness bands against lab equipment that also measured energy expenditure. Sixty subjects wore all eight trackers plus the lab model while they did a series of everyday activities that including typing at a computer and running for just over an hour.

What the men in white coats found was that while some products came close to the lab equipment, some showed more than a 10% variation. So while these new devices can do the job of motivating us to move more, anyone who might be calculating whether they've burned enough calories to tuck into that extra doughnut, might be basing that decision on bad information.

What to do with your data


Getting accurate information isn't the only barrier. Even when the data is accurate, there's still the problem of how manufacturers help people without a sports science degree to interpret and act on what their wearables are telling them.

Knowing your heart rate is one thing, understanding how to use the information to improve your training is another thing entirely.

"How do you help someone who doesn't have a background in sports science to interpret data like their High Metabolic Load Data? That's the problem," admits Jim McEneany from StatSports, whose GPS and accelerometer tracking units are used by Premier League and NFL teams to keep tabs on players in training.

"It's not only the level of information consumers are able to get but how you're going to be able to support them in understanding what the data means. A piece of software and a piece of wearable tech is only as good as the user that's using it."

There's also a fine line between empowering someone and overloading them.

"Trying to decide what level of data you offer is the tough decision that you have to make," continued McEneany and SmartLife's Andy Baker agrees.

“One of the big challenges is to scale this info down to meaningful, understandable information and educating them on why they should care and what they should do with that," he said.

Data has never been the problem, according to Glenn Risely, founder of GCC, whose corporate wellness initiatives use tracking devices to motivate over 300,000 participants across 180 countries.

“Data isn't the answer. If you look at every bathroom in the UK, it's probably had a set of bathroom scales sitting in it for the last 30 years. It doesn't mean that everyone is standing on them every day and understanding what to do as a consequence of what they're seeing. So putting something on your wrist and expecting it to solve all your problems is really short sighted. It's just a piece of the puzzle."


The legal problem

However, turning the data we get from our wearables into useful personal advice faces some legal hurdles. Many countries have strict guidelines relating to how and when health and fitness advice is offered, and it's making manufacturers cautions about giving concrete tips to users.

“The industry is scared of its own shadow, particularly in America where giving [health or fitness] advice is a lawsuit waiting to happen," said Baker. "But in some countries it's not. Once you've learnt which areas you can give advice safely to people, then it will change. Unfortunately, at the moment, most of the technology has come from America where if you've told me I need to get a certain number of hours sleep per night, and then die of a heart attack I'm going to sue you."

Tech can't tell if your head's in the right place

It's this inability to truly personalise the advice to individuals that has Minetti convinced that until we invent technology that can read out emotions, there will always be a place for the personal training approach.

“What technology can never do is prescribe correct exercise, on a daily basis for an individual, whilst taking into consideration many environmental, physical, mental and emotional situations," he argues.

“An experienced personal trainer can analyse, prescribe and monitor a client's training program, as well as encourage, motivate, correctly instruct and most importantly, listen. Technology is not good at listening."

So, unlike some industries that are currently being completely disrupted by technology, the innovation in sports wearables has the potential to make fitness training more accessible.

But whichever way you look at the future of training, it's likely to remain personal.

TAGGED Sport Running

How we test

Kieran Alger


Kieran is a world record-setting runner and one of the UK's most experienced running journalists.

A constant tester of the latest fitness technology, he's always hunting for innovations that can make him run faster, further and generally be in better shape.

Kieran is often found wearing four GPS running watches at once. And to date he's tracked more than 50 marathons, 13 ultras and countless half marathons - including the Marathon Des Sables.

In 2022, he became the first person to run the river Danube from sea to source, a measly 1,830 miles in 66 days. And still had time to test running gear.

Kieran regularly takes running tech to the extremes for Wareable and the likes of Runner's World, Mens Health and Wired.

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