A member might arrive at a gym wearing a Garmin. Another tracks sleep with an Oura ring. For a fitness business trying to use that information, the challenge is not simply getting people to wear devices. It is making data from different brands work together inside one product.
Jonas Ducker encountered that problem firsthand at RookMotion, the company he built with his current co-founders before ROOK. RookMotion made heart rate monitors and software that let gyms and instructors see participants’ effort during a class. Then customers began asking whether members could use the devices they already owned instead. “We were spending more energy on plumbing than on our actual product”, he recalls.
Each wearable provider had its own way of connecting, authorizing users and delivering data. Integrating one brand did not solve the problem for the next, and keeping those connections working demanded continuing engineering time. Jonas and his co-founders saw that the same obstacle faced fitness apps, wellness platforms and other companies trying to build around wearable data. They turned what they had learned at RookMotion into a separate product: ROOK.
One connection, many devices
ROOK Connect gives a company a single API or SDK through which its users can connect compatible wearables. ROOK handles the connections and organizes the incoming information into a consistent format. In practical terms, sleep data from an Oura ring and a Garmin watch can reach a product team with the same field names, rather than requiring separate systems for each device.
That distinction matters to businesses with ideas for coaching, member engagement or wellness products but limited time to maintain dozens of integrations. “The job isn’t only ‘get the data’”, Jonas explains. “It’s ‘understand what’s happening with your users, continuously’”. ROOK Signals extends that work by allowing companies to monitor measures such as resting heart rate, heart rate variability and sleep against an individual user’s baseline, then identify changes.
Jonas arrived at this intersection of fitness and technology by a route that crossed several markets. Born and raised in Germany, he first worked at an Amsterdam fitness-tech startup operating from Medellín and selling into the United States. A later role at a Peru-based startup serving Latin America brought him to Mexico, where he met his current co-founders. Today he lives between Miami and Mexico City and works as ROOK’s COO and CMO, connecting areas of the company while leading much of its marketing and commercial work.
From snapshots to streams
Jonas sees a broader shift behind the demand for ROOK’s tools. Health information has often been captured at isolated moments; wearables make it possible to observe patterns over time. For companies developing fitness and wellness products, the question is becoming less about whether they can collect another step count and more about whether the information helps them offer something useful.
He believes value will increasingly lie in understanding a person’s usual patterns and recognising meaningful changes, rather than presenting raw numbers alone. But he is equally clear that more consequential uses of health data make trust essential. “Security, privacy and consent will separate serious players from everyone else”, he says.
For ROOK, the ambition is to become the infrastructure companies use not only to connect devices, but to build a more continuous picture of each user’s health. Its origin remains a useful reminder for the fitness industry: sometimes the next product begins with a problem a team can no longer afford to keep solving on its own.
Follow the connection: ROOK
