The Future of Digital Fitness

Putting a trainer in your phone

Who are the best “personal change” agents out there? Personal trainers. They know you, build a relationship with you, continually adjust your training, and ultimately get results or lose clients. What’s the “next big thing” in digital fitness? Getting a personal trainer inside your phone.

I’m going to paint a few pictures of the kinds of products we’ll have in the next 1-3 years, and where there are some opportunities for new entrants.

Run coaching: just-in-time, big-data training

Athletes and mere mortals alike love running: Half-marathons and 10k’s are now the fastest growing recreational sports events, and all those runners are spoiled for choice when it comes to run tracking apps. Indeed RunKeeper, MapMyFitness, Nike+ and Strava are some of the most popular fitness apps. While they are awesome trackers (besting $500 GPS watches in many ways), they’re still missing customized personal training. Unless you’re a serious runner, the closest to personal training you might get is picking up an issue of Runners World and trying out one of the workout plans inside. It’ll work, but it’s not customised to you, doesn’t adapt, and it’s about as motivating as… well, as a few pieces of paper stapled together.

Instead, here’s what the future will look like:

For $50 you’ll pick up a Bluetooth heart rate monitor. You’ll launch the training app, where you’ll set a goal: “I want to run my first 10k in 12 weeks.” You’ll lace up, strap on the heart rate monitor, pop in some earbuds and go and do a “fitness test”: You’ll start running, and the app will start to track your pace, heart rate, elevation, maybe even how loudly you’re huffing and puffing. After a few minutes, a voice will say “Great, now sprint all-out for 30 seconds,” and later perhaps “Stop running and stand still to catch your breath for 1 minute.”

Within 15 minutes the app — your digital coach — will know how fast you can run, how your heart reacts to speed/elevation changes, how quickly your heart rate recovers, etc. Now this coach can create a completely personalized training program, suited to your goals and abilities. It will even adjust things mid-workout: “It looks like you’re more tired than usual. Let’s tone it down today and give you a couple more days off before our next run.” Adding sleep data from sensors like the Beddit or Basis will let the the coach know how rested you are, and automatically adjust your training.

I might actually learn to love (or tolerate) running in this future.

Pumping iron: Sensors, Speech and Motivation

Weight training hasn’t been well addressed by existing apps: most weight workout trackers are about as easy to use as diet logbooks, and occasionally throw a haphazard gameification later on top for good measure. That’s nothing like a great trainer, so let’s picture what a great digital coaching experience will be in the near future:

It’s 6 AM and you’re slowly dragging yourself from bed. By the time you’ve poured your cup of coffee, your digital coach (an app) already has your workout for the day planned. Your coach knows you’re still at home, have just woken up (it chats with your sleep sensor), and have a workout scheduled to begin in 30 minutes. Knowing all of this, it reminds you to:

  • Grab your Basis watch (since it’s a heart rate monitor)
  • Wear your Athos shirt (embedded with lots of sensors)
  • Grab you bluetooth headphones (with a microphone)
  • Drink a glass of water before you leave for the gym

As you walk into the gym, a geofence fires and the coach pops a notification onto the phone’s lock screen. You pop in your earbuds, swipe to begin the workout, and jump on a rowing machine to warm up. Your coach is monitoring your heart rate (through the watch) and muscle activity (through the shirt), prompting you to start slow, and then eventually leading you through some “warmup intervals” that feel like a workout by themselves.

Once you’re warm, your coach asks, “Great warmup! How are you feeling?” The gym is a great place for hands-free operation, so for the rest of your workout, your phone will stay in your pocket and you’ll interact with your coach by voice.

“I’m feeling good.”

“Great! Today is an upper body day, so we’ll start with some pull-ups, and then move to bench presses. Let me know when you’re ready to begin.”

You walk under some pull-up bars and say “Ready.”

“Great, you did 3 sets of 12 last week, let’s try 15 today. Go!”

You jump up and start your set. Your smart shirt is tracking all of your motion, so with each rep your coach is counting for you, “… ten, eleven, twelve…nice job! Just 3 more for a new record. Two more. One more. Great job! You smashed your record! How do you feel?”

“Good. Damn that was hard!”

“Not too hard for you, it seems! Alright, next up: bench press. Last week you did 3 sets of 10 reps at 100 pounds. I think you can do 125 this week. Sound good?”

It seems like a big step, but the last time your coach noticed that your heart rate never got too high, and your smart shirt showed that your muscles never got particularly fatigued. You’re doing great this workout, so it recommends pushing a bit harder.

“Sounds good, let’s do it.”

“Great! Set up your bar with 40 pounds on each side, and tell me when you’re ready to begin.”


“Great, remember to exhale as you press the bar away from you, and start whenever you’re ready.”

This time, as you get into position and start your reps, not only is your coach counting reps, but is indeed watching your form. “Let the bar come down 2 inches more, pause, and then explode upwards. Yes, that’s perfect! Just 5 more reps like that one,” it says, paying attention to all sorts subtle muscle activity that even the best human coach would struggle to see.

As you leave the gym, your coach gives you a summary of your workout, and pays special attention to today’s personal records. When you get home later in the evening, your coach reminds you that an intense workout deserves a good night’s sleep, so you might consider getting to bed by 11.

For people who can afford a human trainer, a digital coach just helps gather more data about their workouts and performance, which can be shared with the trainer. For everyone else, imagine how powerful it’ll be to have an adaptive, intelligent, personal coach for no more money than a set of P90X DVDs.

The Living Room: Move over Kinect

What if your ambitions are a bit more modest? Sure we’re got great coaches for runners and gym rats. What about people who are anxious to visit a gym, and would rather just watch a Zumba DVD in their living room? No problem, your iPhone 7s has you covered:

You turn on your TV and launch the Dancing with the Stars Workout app on your phone. You place the phone at the base of the TV, where the stereoscopic (3D) camera on the front has a good view of you. Indeed, your phone + TV is basically like a combo XBox / Kinect that fits in a pocket. No walking up to the TV to hit a button, or getting sweat all over your phone: the interface is all just using your voice and body. After about 10 minutes, the app gives you a one minute break.

“Stand still and look straight at the TV. Please keep your head inside this box.”

The TV screen shows a mirror image of you, with a box to keep your face inside. Why? Unlike our previous athletes, you’re just getting started with fitness, so using this app was all the commitment we expect. No sensors or heart rate straps for you. No problem, though, because we can actually calculate your heart and respiration rates just by looking at you.

Basically we can bring the group-exercise experience right into your living room with no special hardware, for the cost of an app. Oh, but unlike a standard group class, this coach knows exactly who you are, how you’ve been progressing, and when it’s the right time for you to add some variety to your routine. Also, since your phone will be able to have a 3D view of you, it will also be able to monitor things like range of motion, undiagnosed injuries, etc. and track both your progress, as well as further customise workouts for your body. Living room and hotel room workouts will never be the same.

The opportunity: Data and Emotion

There will be many companies that build apps in this space, but I think there are going to be a few specific pieces that the winning firms will need.


There will be much more sensor data coming from smart shirts, armbands, muscle “quality” sensors, and other devices we haven’t invented yet. The winners will take the lead on a combination of fundamental sensor innovation as well as the health/coaching-specific analysis of this data. Indeed, while other companies release one activity tracking wristband after another, Apple has been quietly hiring execs, scientists and engineers from companies like Sano Intelligence, Proteus and Massimo (all serious, medical-grade health sensor companies), and I’d bet they’re making big investments in fundamental sensor technology. Gathering the most data, unobtrusively, and making sense of that data, are long term investments that will pay off with huge barriers to entry.


An Israeli friend of mine remarked that his Anglo-Saxon coach had figured out how to invoke “Jewish grandmother guilt” in him when he slacked off. This is the nuance that separates mediocre coaches from great ones. The best know you, build a relationship with you, and learn how to motivate you. On a day when I’m recovering from the flu and didn’t sleep well, I’d like a lot more gentle coaching and “attaboy” remarks than usual. When I’m on my game, it is actually fairly motivating to tell me half-way through a set, “My grandmother could do better. Come on, step it up!” It’s not just about personalizing for the individual, but for that individual at that time. The company that gets the most people using their platform, and mines the data to test various different kinds of messages and interventions, will have acquired a tremendous data asset. Once you’ve got the best “coach” in the cloud, that’s a barrier to entry.

The future’s almost here

Much of the building blocks of this future vision are already here, and others are around the corner.

Already on the market

Bluetooth headphones: I use the sweat-proof (they claim) Bluebuds.

Bluetooth heart rate monitor: Basis B1, Polar, and many others already exist.

Sleep monitors: Beddit, Jawbone, Fitbit, Withings.

Voice interfaces: Siri’s actually getting to be pretty good.

Around the corner

Stereoscopic cameras: Creative Labs has them for computers, Intel has them for tablet and laptop makers.

Ultimately great developers are going to pull the pieces together, and it won’t be very long until these ideas are real products you’ll have in your hands.

If you enjoyed this post, you should follow me on Twitter.

Thanks to @seemakumar, @chudson, @jensmccabe, @bsrubin, @jamescham, and @youngjhmb for providing feedback on earlier drafts.

Cover photo by Runar Eilertsen.

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