The best indoor cardio setup with Zwift

  • health
  • fitness
  • products
5 min read / 1324 words

A year ago I started researching the best cardio equipment that also provided a decent level of engagement, together with performance metrics compatible with Apple HealthKit and the activity app.

Software didn't seriously enter the gym equipment up until recently. The vast majority of the super expensive machines you find at the gym aren't very advanced technology-wise. This started to change a few years ago:

  • Apple created GymKit, an SDK to pair your Apple Watch with compatible bluetooth gym equipment. The idea behind this is that you can make the heart rate sensor, UI and other features of the watch work with the gym equipment. Sessions (duration, type, calories, etc) will then get saved to the activity app and populate the HealthKit database.
  • Gym equipment manufacturers like the Italian TechnoGym, US brands and others started to adopt more advanced software and multimedia elements into their products.
  • Home fitness equipment manufacturers started embedding bluetooth in their equipment and exposing their sensor data, sometimes through proprietary apps to be installed on users phones or tablets.

Right now the indoor biking world has the most advanced setup and ecosystem. A lot of brands (mainly from Europe) are offering indoor "smart" or "interactive" trainers, basically bike trainers that can connect over bluetooth. There are two main categories of indoor bike trainers:

  • rollers. The rear wheel of your own bike simply slides on a roller while the trainer stands firmly on the ground so that you can freely pedal indoor.
  • direct drive. The rear hub of your own bike is directly attached to the trainer. While you pedal, the bike chain will spin a wheel inside the trainer itself. Different models will differ around the design and drive mechanisms. Less expensive models have the main hub and wheel spin a dynamo through a rubber belt. More expensive models will use electromagnetic resistance to dynamically adjust the spinning hub and wheel, improving accuracy and resulting in a quiter operation.

A year ago I got a smart roller trainer, coupled with a special rear tyre to reduce noise during pedaling. I found out it was still created tiny rubber particles all around and it made me cough for a month. Long story short, shortly thereafter I did send it back as it was spreading rubber particles all over the place, even after the run-in period. Very unhealthy.

Direct drive trainers are more expensive than rollers but are way more precise in measuring power (the watts you generate while pedaling). What scared me was having to detach and reattach the bike for every session, so that I could easily store away the trainer to have more space in the room. This turned out to be fairly easy: my bike is stored in another room, without the back wheel, with the rear end standing on a tripod. The whole process of taking the bike from there and attaching it to the trainer takes two minutes. This way both the bike and the trainer take very little space when not in use.

The trainer I bought is the one I recommend as it's the best value for money, the Elite Direto. Very recently replaced by the new Direto X. They're even made in Italy.

Once you get your bike on the trainer, you can start spinning. That will not make use of the 'smart' capabilities of the trainer though. To do that you have to connect it via bluetooth to either your phone, tablet, PC, Mac or Apple TV. There are a lot of different apps that can take control of your trainer so that, when you pedal, you can feel dynamic resistance. Free ones (from Elite and others) are basic: you can simulate a slope and other parameters while the interface tells you the watts you generate, speed and other metrics.

You will basically have turned your own bike into an electronic gym bike, that can cost around $5000 or more. The best part is that you can go the next step and get an engaging simulation, coaching and training, all while riding indoor.

To go the next step you will need more advanced apps. My setup is as follows (since late 2018):

  • Interactive trainer: Elite Direto
  • Mountain Bike: Rockrider 540
  • Apps: Zwift and Zwift companion
  • main screen: Apple TV 4K (connected with a TV) running the Zwift app
  • remote and second screen: iPhone running the Zwift companion app
  • heart rate monitoring: Apple Watch running the Zwift companion app

Let's brake it down. The Direto is the best value for money trainer. The Decathlon Rockrider 540 is also good value for money with a 100% aluminum frame and, most importantly, a 7 speeds shimano rear hub. So any bike with a 7 speed rear cassette or above will work with the Elite Direto. You're at around 1000$ for an Elite Direto plus a new compatible bike like this one.

Zwift is a videogame simulation that can run on a PC, Mac, iOS, Android, or Apple TV and costs 15$ per month after a free monthly trial. It has a virtual world (Watopia) and more or less realistic versions of a few cities like New York and London. It is "multiplayer" so your avatar will run together with hundreds of other live riders at the same time. This means you can take races, run in groups, run with your friends, etc. You can freely roam and bike in the "game" and every slope, hill, mountain, downhill or flat road will feel real as Zwift is constantly communicating with your interactive trainer and adjusting its resistance. The other main mode is called ERG and it will set your trainer as an ergometer. It means that you will have to ride at a specified amount of watts, no matter the slope. There are training programs in Zwift that will leverage this mode to make you go through a specific workout, like the one you see in the main image at the top of this post. They can go from simple workouts to very elaborate training plans spanning months.

I use Zwift on an Apple TV 4K as the main screen, then the Zwift companion app on my iPhone, mounted on the handlebars. This app is used as a second screen and can display the map, dashboard and all sorts of interactive controls. It will also stream live heart rate data from my Apple Watch to Zwift itself. To make this work, my iPhone needs to be in the same WiFi network as the main Zwift app running on my Apple TV (in my case connected via an Ethernet cable). This setup will save automatically all the workout data to the health and activity apps in iOS, populating heart rate frequency data, activity duration, calories, etc.

You can also set up Zwift to save and upload data to other apps like Strava, TrainingPeaks and others at the end of every session. I have experimented with a couple and did stick to TrainingPeaks (free version) as it can show a couple more metrics around workouts.

I have experimented with chest bands to monitor heart rate (supposedly the gold standard) but have found the Apple Watch to have the same accuracy. Given its added convenience, that's what I use for heart rate monitoring.

When I'm abroad, as an example, I can easily deactivate the Zwift subscription (via the App Store subscriptions panel) and then activate it again when I need it. In theory you could still use Zwift with just your phone (and a sensor) in a regular gym by attaching sensors (power meters) to a spin bike or a traditional gym bike, a hack mainly used by people who constantly travel.

Also I can always put the back wheel on again and ride the bike outdoor whenever I feel like.

In conclusion, this kind of setup is not only cool but very useful for people who want an engaging workout experience with actionable and accurate metrics for performance.