Effects of Long Duration Cycling in People With Type 1 Diabetes

NCT07286019 | Active Not Recruiting

• 2 other identifiers: UdG-PEDAL-T1D2025.110
• Study Type: interventional
• Target: 29
• Locations: 1 country
• Sites: 1

Brief Summary

The goal of this interventional study is to build a high quality, real world multimodal dataset that combines continuous glucose monitoring (CGM), wearable and fitness data, performance metrics, and saliva and urine omics collected during a prolonged, moderate intensity outdoor gravel-cycling session in adults with type 1 diabetes (T1D). The main questions it aims to answer are:

• Can we collect and synchronize comprehensive CGM, physiological, performance, and omics data around a single cycling session to enable further artificial intelligence (AI) model development?
• What molecular changes in saliva and urine occur during exercise, and how do they relate to glycemic outcomes? Participants will:
• Complete a supervised \~75 km gravel-cycling route at their own pace under real-world conditions, without protocolized therapy adjustments.
• Wear a Dexcom G7 starting \~4 days before the ride and continue through the sensor lifespan to capture CGM data.
• Provide saliva and urine immediately before and after the ride for epigenomic and proteomic analyses. This study will generate an integrated resource that supports the development and validation of AI models for predicting glucose responses to exercise in T1D and will help guide future studies on how prolonged exercise affects glucose control.

Conditions

Type 1 Diabetes (T1D)

Keywords

Insulin; Exercise; Diabetes Mellitus, Type 1

Outcome Measures

Primary Outcomes (1)

• Proportion of participants with a complete multimodal dataset collected

  Percentage of enrolled participants for whom all planned study data are successfully collected and available in the study database at the final follow-up visit. A complete multimodal dataset is defined as: 1) continuous monitoring data for the full wear period used in the study, 2) saliva and urine samples obtained immediately before and immediately after the cycling event (visit 3), and 3) cycling performance and physiological data (heart rate, power, GPS) recorded during the gravel cycling event (visit 3).

  At visit 4 ( final follow-up), approximately 8 to 9 days after the cycling event (visit 3).

Secondary Outcomes (12)

• Percentage of CGM time in glucose range 70-180 mg/dl

  Baseline (days -4 to -1 before the cycling event), during the cycling event (day 0), and post-event folow up (days +1 to +5 after the cycling event).

• Percentage of CGM time in hypoglycemia (<54 mg/dl)

  Baseline (days -4 to -1 before the cycling event), during the cycling event (day 0), and post-event folow up (days +1 to +5 after the cycling event).

• Percentage of CGM time in hyperglycemia (>250 mg/dl)

  Baseline (days -4 to -1 before the cycling event), during the cycling event (day 0), and post-event folow up (days +1 to +5 after the cycling event).

• Number of daily hypoglycemic events

  Baseline (days -4 to -1 before the cycling event), during the cycling event (day 0), and post-event folow up (days +1 to +5 after the cycling event).

• Median glucose concentration

  Baseline (days -4 to -1 before the cycling event), during the cycling event (day 0), and post-event folow up (days +1 to +5 after the cycling event).

Other Outcomes (4)

• Number of self-reported exercise events during CGM monitoring

  From CGM sensor insertion to CGM sensor removal, approximately 10 days in total.

• Number of self-reported meal events during CGM monitoring

  From CGM sensor insertion to CGM sensor removal, approximately 10 days in total.

• Total daily insulin dose during CGM monitoring

  From CGM sensor insertion to CGM sensor removal, approximately 10 days in total.

Study Arms (2)

Adults with type 1 diabetes

EXPERIMENTAL

Adults with type 1 diabetes complete one supervised outdoor gravel cycling route of \~75 km under real-world conditions that represent moderate-intensity cycling. Intensity is not prescribed by the protocol and participants will regulate their effort themselves. Participants continue their usual insulin therapy with no protocolized insulin adjustments. A Dexcom G7 sensor is started \~4 days before the event and worn through its life to capture baseline/during/post-exercise data. Saliva and urine are collected immediately before and after the ride for omics analyses.

Behavioral: Prolonged moderate-intensity cycling session

Adults without diabetes

EXPERIMENTAL

Adults without diabetes complete the same supervised gravel cycling route of \~75 km under real-world, moderate intensity conditions. Intensity is not prescribed by the protocol and participants will regulate their effort themselves. A Dexcom G7 sensor is started \~4 days before the event and worn through its life to capture glycemic data. Saliva and urine are collected immediately before and after the ride for omics analyses.

Behavioral: Prolonged moderate-intensity cycling session

Interventions

Prolonged moderate-intensity cycling session BEHAVIORAL

One single outdoor gravel ride (\~75km) performed at a comfortable, sustainable intensity appropriate for each participant. The protocol does not prescribe specific speed, power, or heart-rate targets. Safety monitoring and on-route support will be provided to participants.

Adults with type 1 diabetes; Adults without diabetes

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Type 1 diabetes for \> 5 years.
• Age between 18-60 years.
• HbA1c ≤ 8.5%.
• Body mass index between 18 and 30 kg/m².
• Physically active (≥ 4 hours/week of exercise).
• Laboratory data and EKG without alterations of the last 12 months.
• Valid Type 2 sports medical examination, which includes a monitored stress test with continuous ECG and blood pressure monitoring, as well as an official medical certificate confirming fitness to participate in this study.
• Experience using CGM sensors and be used to self-monitor blood glucose and carbohydrate counting.

You may not qualify if:

• Unable to ride gravel bikes.
• Unable to use clipless pedals.
• Pregnancy and breastfeeding.
• Hypoglycemia unawareness (Clarke Test \> 3).
• Severe hypoglycemia in the previous 6 monhts.
• Progressive fatal disease.
• History of drug or alcohol abuse.
• Impaired liver function.
• Clinically relevant microvascular complications (macroalbuminuria, pre-proliferative and proliferative retinopathy), cardiovascular, hepatic, neurological, endocrine or other systemic disease, apart from T1D.
• Mental conditions that prevent the subject from understanding the nature, purpose and possible consequences of the study.
• Using an experimental drug or device during the prior 30 days.

Sponsors & Collaborators

• Universitat de Girona: lead
• University Hospital of Girona Dr. Josep Trueta: collaborator

Study Sites (1)

Modeling & Intelligent Control Engineering Laboraotry (Universitat de Girona)

Girona, Girona, 17003, Spain

Location

Related Links

• ENIA UdG-Dexcom Chair

MeSH Terms

Conditions

Diabetes Mellitus, Type 1; Insulin Resistance; Motor Activity

Condition Hierarchy (Ancestors)

Diabetes Mellitus; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Endocrine System Diseases; Autoimmune Diseases; Immune System Diseases; Hyperinsulinism; Behavior

Study Officials

• Eduardo Esteve

  University Hospital of Girona Dr. Josep Trueta

  STUDY DIRECTOR

• Josep Vehi

  Universitat de Girona

  PRINCIPAL INVESTIGATOR

• Anna Prats

  Escola Universitària de la Salut i l'Esport

  PRINCIPAL INVESTIGATOR

• Aleix Beneyto

  Universitat de Girona

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Full Professor in Control and Biomedical Engineering

Model Details: Non-randomized parallel assignment by cohort: T1D vs non T1D

Study Record Dates

• First Submitted: November 17, 2025
• First Posted: December 16, 2025
• Study Start: November 22, 2025
• Primary Completion: December 1, 2025
• Study Completion: December 1, 2025
• Last Updated: December 16, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share

Locations

ES (1)