Using a Personalized Decision Support Tool to Help People With Type 1 Diabetes Manage Exercise (NEXT)

Stanford University

Status: Not yet enrolling

Conditions: Type 1 Diabetes (T1D); Type 1 Diabetes Mellitus (T1DM); Type 1 Diabetes Mellitis

Treatments: Device: netIOB & Exercise Toolkit (NEXT); Behavioral: Standard-of-Care Guidance (SoC); Behavioral: Usual Care (UC)

Study type: Interventional

Funder types: Other

Identifiers

NCT07226583

2407-07175 (Other Grant/Funding Number)

82224

Details and patient eligibility

About

This study evaluates a digital decision-support tool designed to help individuals with type 1 diabetes prepare for exercise. This netIOB & Exercise Tool (NEXT) uses glucose data and insulin delivery history to recommend individualized strategies such as carbohydrate intake, insulin adjustments, or delays in exercise start time.

Participants will complete three structured aerobic or mixed-exercise sessions using different guidance approaches:

(A) published consensus-based standard-of-care guidelines (B) usual personal care routines (C) the NEXT tool

The study compares glucose outcomes, safety, and carbohydrate use across these conditions to inform better exercise preparation and support tools for people with diabetes.

Full description

People with type 1 diabetes often experience unpredictable changes in blood glucose levels before, during, and after physical activity. While consensus guidelines exist to help mitigate these risks, many individuals continue to encounter hypoglycemia or rely on excessive carbohydrate intake around exercise.

This study evaluates a software-based tool, netIOB & Exercise Toolkit (NEXT), that provides real-time, individualized guidance for exercise preparation. The tool uses data from continuous glucose monitors (CGMs), insulin delivery history, and exercise timing to suggest adjustments such as carbohydrate intake, temporary targets, or delayed start times. Its goal is to reduce hypoglycemia and carbohydrate burden while preserving exercise safety and feasibility.

The trial uses a randomized, crossover design in which participants complete three supervised moderate-intensity exercise sessions, each under a different preparation strategy. The guidance methods include consensus standard-of-care, usual personal care, and the investigational NEXT tool. Each session is followed for 48 hours to assess glycemic and behavioral outcomes.

Exploratory analyses will stratify glycemic and treatment outcomes based on pre-exercise net insulin-on-board (netIOB) levels, categorized into predefined strata (e.g., 0.0-1.0u, 1.0-2.0u, 2.0-3.0u, 3.0u+), to assess potential effect modification across intervention arms.

The NEXT tool is investigational and classified as IDE-exempt. Findings from this study may inform the design of future clinical trials and support the development of open-source methods for exercise preparation in diabetes.

Enrollment: 10 estimated patients

Sex: All

Ages: 18 to 60 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

• Adults between the age of 18-60 years
• Diagnosis of type 1 diabetes for >1 year (based on investigator's clinical judgement)
• Using Tandem Control-IQ and Dexcom G7 for ≥1 month
• Able to sustain moderate intensity walking for 60 minutes (target 50-60% age-predicted HR max) without limitation.
• Use of a stable insulin delivery regimen, with no planned changes in settings or dosing strategy during the study period, and consistent continuous glucose monitor (CGM) use in the prior 1 month (>80% data)

Exclusion criteria

• Use of non-continuous subcutaneous insulin infusion (CSII) during study, including long-acting or inhalable insulins.
• Use of other medications with the potential to confound glycemia (including SGLT-2 inhibitors, GIP or GLP-1 receptor agonists) unless on a stable regimen with no planned changes during the study.
• Use of systemic steroids within 4 weeks of planned study participation.
• Severe hypoglycemia (requiring assistance) or DKA within the prior 6 months.
• Intercurrent illness or medical conditions that preclude safe participation in moderate-intensity exercise (e.g. unstable cardiopulmonary disease, uncontrolled arrhythmia, or uncontrolled hypertension), as previously assessed by the individual's primary care physician.
• Pregnancy, lactation, or planned pregnancy during participation.
• Renal insufficiency with eGR <45 mL/min/1.73 m2, dialysis, or adrenal insufficiency.
• Known coronary disease or angina that limits moderate activity, or myocardial infarction/PCI/CABG within 12 months.
• Concurrent participation in another interventional drug/device study within 30 days
• Inability to comply with study procedures or safety requirements (e.g., cannot achieve target HR zone, cannot attend visits, or cannot enable device data access), or otherwise deemed unsuitable by the investigator.

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: None (Open label)

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10 participants in 3 patient groups

Standard-of-Care (SoC)

Other group

Description:

Participants follow consensus-based guidance for insulin and carbohydrate adjustments around exercise, as outlined in current international standards. These recommendations are applied by study staff in advance of the exercise session.

Treatment:

Behavioral: Standard-of-Care Guidance (SoC)

Usual Care (UC)

Other group

Description:

Participants use their own strategies for managing insulin and carbohydrate around exercise.

Treatment:

Behavioral: Usual Care (UC)

netIOB & Exercise Toolkit (NEXT)

Experimental group

Description:

Physicians receive personalized, algorithm-informed recommendations for exercise-related insulin and carbohydrate adjustments. Recommendations are generated using the investigational netIOB \& Exercise Toolkit based on CGM data, insulin history, and real-time inputs.

Treatment:

Device: netIOB & Exercise Toolkit (NEXT)