Building Slé: Gamifying Personal Mobility


By Chessin Gertler, Founder @ Slé

Small nudges in individual habits have the potential for outsized effects — Tech has cracked the code on how to harness our own psychology to improve fitness. The way we approach climate action is next.

Over the eight days between Christmas and New Years this year, I rode the Festive 500, covering 500 km on my bike through rain, sleet, snow — and the rare patch of sun. The annual challenge provides motivation to get outside for what isn’t the nicest time of year (for those with a northern hemisphere bias) and gives me an opportunity for some deep thought and a chance to reset for the coming year, not to mention shed a bit of holiday weight.

I track my rides on my Garmin bike computer, which I have set up to upload to Strava automatically when I finish, and watch my progress tick away over the week. This go, I completed 506.7 km (314.8 mi) with 5,096 m (16,719 ft) of elevation gain, over 19h 41m. My stats are enshrined in a digital badge in my Strava Trophy Case and I get a chance, alongside the nearly 50,000 others who completed the challenge (170,000 signed up), to win a nice bicycle. I wasn’t the lucky winner this time.

What strikes me about this experience is how a simple nudge can tap into my reward system and fundamentally alter my behavior. The incentivization built into the experience — the trio of community inclusion, award, and the possibility of a prize — kept me going through what were objectively some truly unpleasant hours on the bike. Getting up in the dark, dressing for 50 kms at 23 degrees F — duct taping the vents on my shoes so my toes don’t go numb, layering enough to stay warm but not sweat so much that it freezes, etc… It’s a commitment. In the end, I feel fit and healthy and gain a sense of accomplishment and inclusion in what I perceive to be a select group. It’s a great way to start 2023, though maybe a poor substitute for a vacation.

Connected Fitness has taken off over the past decade. Platforms like Strava, Fitbit, Peloton, Zwift, Apple Health and Whoop have collectively cracked the code on how connectivity and gamification can change personal fitness behavior in such profound ways so as to spawn a multi-billion dollar market. Before Peloton, riding a stationary bike at home was basically just pedaling going nowhere. Maybe you had music or a tv to keep you occupied, if you were lucky. Now, it’s an immersive, communal, competitive, experience. Zwift takes the same approach from a VR and race-oriented angle. Whoop is a pioneering wearable tech, but ask most users and they will tell you its main draw is still its communal, connected UX. Strava, brilliantly, aggregates all of this, while adding rudimentary AR to outdoor fitness activities, e.g. Strava Segments, and its own layer of community and competition.

The power of these platforms, in my opinion, doesn’t lie necessarily in an ability to create profound development in users’ physical fitness, but rather in an impressively effective ability to create marginal changes in behavior, that in turn create tangibly improved experiences. Not everyone on Strava is doing the Festive 500, but most people who have used the app have some sort of experience of increased motivation to run that extra km, swim that extra lap, or get in that extra ride on the bike. Users of these apps work to close their rings in Apple Health, compete with friends on their Whoop team, or get a better looking pair of sunglasses for their avatar on Zwift. The results usually aren’t a new rippling six-pack or Olympic level VO₂ max, but rather a better, more enjoyable workout, and an increased desire to come back and do it again.

Slé is inspired by Connected Fitness. The bet I’m making in building it is that the same psychology of incentivization that these fitness platforms deliver through connectivity, gamification and rewards can be applied to human mobility beyond the fitness space, and act as a powerful tool for climate action. Of all economic sectors, the transportation system generates the largest share of greenhouse gases. Unsustainable mobility patterns affect pollution, traffic, health, urban economics, and livability at large. Slé catalyzes improvement in individual users’ mobility habits by nudging them in their daily transportation practices towards greater efficiency. Built on an algorithm that considers users’ contributions to emissions, traffic, and their own personal health, Slé rewards more use of cycling, micromobility, transit, and EVs when possible, providing usable information, incentives, and friendly competition. It does not penalize less efficient transportation practices, rather offering insights and incentives for marginal improvement.

What’s most exciting to me about the possibilities of Slé is the platform’s ability to catalyze a collective move towards more sustainable transportation culture for entire metropolitan areas and beyond. A ten percent increase in efficiency for a specific user, while a tangible improvement to an individual’s life, does not have a measurable effect on climate change. A ten percent increase in efficiency for an urban population — or even a segment of that population — will fundamentally alter the health of a city, improving air quality, traffic, and its economy. Data from these shifts can catalyze policy decisions regarding transportation infrastructure, transit, taxation, and more.

Slé is pioneering Connected Mobility. While Connected Fitness targets only the small segment of the population that exercises regularly, virtually every human being on the planet possesses some sort of transportation-based carbon footprint. Through passive recognition of transportation modalities through users’ smartphones and wearables, API integration into transportation hardware networks, and more, I am building Slé to transform the way we move in and around cities from a solitary journey to an immersive, communal and highly efficient experience.

Version 1 of the Slé App will be available in the Apple App Store March 2023. For more information and to join our waiting list, please visit or email

I will be sharing more thoughts behind Slé in new posts in the coming weeks and months.

Originally published in Medium