Model

FITTER

guideline-grounded multi-agent LLM for FITT-VP exercise prescription from EHR + Fitbit (All of Us)

Parameters
9B
Year
2026
Form factor
Wrist
PreprintCatalog paper date: 2026Added to atlas: Nov 5, 2026Source

Activity counts measure attention, not model quality. Missing counts are unknown. Publication status follows the linked source; a listed venue alone does not confirm peer review.

FITTER is a multi-agent LLM framework that writes guideline-grounded FITT-VP exercise prescriptions from linked EHR and Fitbit data. Deterministic audits correct rule-checkable safety violations. Evaluated on 400 All of Us participants (300 cancer, 100 stroke) against five LLM comparators.

Parameters
9B
Signals
HR, Activity, EHR, Text
Form factor
Wrist
Year
2026
Architecture

Multi-agent LLM pipeline on an open-weight Qwen3.5-9B backbone with deterministic guideline/safety auditing; outputs FITT-VP (frequency, intensity, time, type, volume, progression) prescriptions

Pretraining data

No pretraining; prompting/agentic pipeline over All of Us EHR + Fitbit data

License

arXiv perpetual non-exclusive license; code repository not released

At a glance
Type
Task model
Form factor
Wrist
Parameters
9B
Architecture
Multi-agent LLM pipeline on an open-weight Qwen3.5-9B backbone with deterministic guideline/safety auditing; outputs FITT-VP (frequency, intensity, time, type, volume, progression) prescriptions
Venue
arXiv 2611.03983v1 (2026-11-02)
Year
2026
DOI
Not reported
Code
Not released
Weights
Not released
Licence
arXiv perpetual non-exclusive license; code repository not released
Caveats
Not reported
Datasets
Not reported
Added
Nov 5, 2026
Updated
Nov 5, 2026

Abstract

Translating population-level exercise guidance into individualized prescriptions requires integrating clinical and wearable data, including diagnoses, medications, functional limitations, and baseline activity, with condition-specific recommendations, a process difficult to scale beyond specialist rehabilitation settings. We developed FITTER, a multi-agent framework that integrates these data with condition-specific guidance to generate personalized FITT-VP prescriptions and applies deterministic safety audit and repair to correct rule-checkable violations. We evaluated FITTER using data from 400 All of Us participants (300 cancer, 100 stroke) against five LLM comparators through computational evaluation, ablation, and structured clinician review. FITTER achieved 98.5% safety-constraint compliance versus 75.8-85.8% for comparators and showed greater quantitative dosing precision and guideline alignment. Cancer-cohort ablation identified safety audit and repair as the largest contributor to safety-constraint compliance. Clinicians reviewed 80 prescriptions across safety, personalization, instruction concreteness, anticipated effectiveness, and clinical acceptability. FITTER provides a clinician-facing approach integrating clinical and wearable data, guidance, and explicit safety constraints.

Verbatim fromarXiv· arXiv metadata (abstracts are released under CC0)

How it works

How FITTER works: Input signals → Model → Downstream tasksInput signals: HR; Activity; EHR; Text (Language). Pretraining data: No pretraining; prompting/agentic pipeline over All of Us EHR + Fitbit data. Model: FITTER, 9B parameters (Language-aligned).Input signalsHRHRActivityActivityEHREHRText: LanguageTextLanguagePretraining data: No pretraining; prompting/agentic pipeline over All of Us EHR + Fitbit dataPretraining dataNo pretraining; prompting/agentic pipeline…ModelFITTER9B parametersLanguage-aligned
Pretraining data
No pretraining; prompting/agentic pipeline over All of Us EHR + Fitbit data
Architecture
Multi-agent LLM pipeline on an open-weight Qwen3.5-9B backbone with deterministic guideline/safety auditing; outputs FITT-VP (frequency, intensity, time, type, volume, progression) prescriptions
Inputs
HR, Activity, EHR, Text
Approach
LLM agent · multi agent · exercise prescription · FITT VP · Fitbit · All of Us

Datasets used

No public datasets linked yet.

Papers· 1

Authors· 12

Cite this model

Cite the publication recorded for this model. Check it against the publisher before submitting.

Li, X., Lin, Y., Wu, Y., Wang, F., Wang, M., Gary, R. A., Kariuki, J., Smith, J., Billinger, S. A., Xiao, C., Hu, X., & Yan, R. (2026). A Guideline-Grounded Multi-Agent Framework for Personalized Exercise Prescription from Clinical and Wearable Data (FITTER; arXiv 2611.03983). arXiv 2611.03983v1. https://arxiv.org/abs/2611.03983
Li, Xintong, Yufen Lin, Yuhua Wu, Fengran Wang, Minxiao Wang, Rebecca A. Gary, and Jacob Kariuki, et al. 2026. "A Guideline-Grounded Multi-Agent Framework for Personalized Exercise Prescription from Clinical and Wearable Data (FITTER; arXiv 2611.03983)." arXiv 2611.03983v1. https://arxiv.org/abs/2611.03983.
Li, X., Lin, Y., Wu, Y., Wang, F., Wang, M., Gary, R. A. and Kariuki, J. et al. (2026) 'A Guideline-Grounded Multi-Agent Framework for Personalized Exercise Prescription from Clinical and Wearable Data (FITTER; arXiv 2611.03983)', arXiv 2611.03983v1. Available at: https://arxiv.org/abs/2611.03983
Li, Xintong, et al. "A Guideline-Grounded Multi-Agent Framework for Personalized Exercise Prescription from Clinical and Wearable Data (FITTER; arXiv 2611.03983)." arXiv 2611.03983v1, 2026. https://arxiv.org/abs/2611.03983.
X. Li et al., "A Guideline-Grounded Multi-Agent Framework for Personalized Exercise Prescription from Clinical and Wearable Data (FITTER; arXiv 2611.03983)," arXiv 2611.03983v1, 2026, [Online]. Available: https://arxiv.org/abs/2611.03983.
@misc{li2026guidelinegrounded,
  title         = {{A Guideline-Grounded Multi-Agent Framework for Personalized Exercise Prescription from Clinical and Wearable Data (FITTER; arXiv 2611.03983)}},
  author        = {Li, Xintong and Lin, Yufen and Wu, Yuhua and Wang, Fengran and Wang, Minxiao and Gary, Rebecca A. and Kariuki, Jacob and Smith, James and Billinger, Sandra A. and Xiao, Canhua and Hu, Xiao and Yan, Runze},
  year          = {2026},
  howpublished  = {arXiv 2611.03983v1},
  eprint        = {2611.03983},
  archivePrefix = {arXiv}
}

Source metadata: 2026

Record updated Nov 5, 2026

History

  1. Added to the ChatPPG research hub