Taking part in out “what-if” futures with a sensor world mannequin
Realizing your well being age tells you the place you stand at this time. Turning that quantity into a personalised plan requires answering a “what-if” (or counterfactual) query: What is going to occur to my physique over the following 12 weeks if I alter particular habits, and which plan can I realistically stick to?
Merely plugging new step or sleep targets right into a static calculator misses how the physique adapts as a related system. Once you persistently transfer extra and sleep higher over a number of weeks, your resting coronary heart charge and coronary heart charge variability regularly enhance too, creating additional well being advantages downstream.
To seize these dynamics, we developed Sensor World Mannequin (SensorWM), an action-conditioned world mannequin pre-trained on 2.28 million person-weeks of de-identified knowledge from roughly 100,000 consenting Fitbit customers. Given two weeks of baseline wearable knowledge, SensorWM forecasts how 20 physiological markers will evolve over the following 12 weeks beneath totally different day by day steps, sleep, and cardio routines, outperforming general-purpose time-series basis fashions like TimesFM whereas preserving the medical patterns related to diabetes, hypertension, and insulin resistance.
We paired SensorWM with a feasibility-constrained optimizer and a language mannequin teaching agent to do three issues:
- Simulate: SensorWM rolls out 125 candidate 12-week behavior combos for every individual, evaluating them in opposition to a “status-quo” projection if habits keep the identical.
- Filter for realism and security: Probably the most aggressive exercise plan would not assist if it causes burnout in week two. Our optimizer weighs projected health-age reductions in opposition to every individual’s historic behavior flexibility and medical security bounds, selecting a extra formidable goal (−2.3 years) for somebody with excessive baseline flexibility, and a gentler ramp (−1.3 years) for somebody whose routine is extra constrained.
- Coach: The language mannequin interprets the top-ranked pathways right into a supportive, progressive 12-week teaching plan.
