High-intensity Interval Exercise Compared With Continuous Moderate Exercise on Glycemia in Postabsorptive vs. Postprandial State in Adults With Type 1 Diabetes (Interdiab 1)

The Protective Role of High-intensity Interval Exercise Compared With Continuous Moderate Exercise on Glycemia Decrease is More Relevant in Postabsorptive vs. Postprandial State in Adults With Type 1 Diabetes

This randomized crossover trial examined whether exercise modality (high-intensity interval exercise vs. moderate-intensity continuous exercise) and timing relative to meals (postprandial vs. postabsorptive) influence glycemic responses in physically active adults with type 1 diabetes. Participants completed four cycling sessions matched for total mechanical load, and glucose levels were monitored during exercise and for 24 hours afterward while accounting for dietary intake and insulin administration. The study hypothesized that glycemic responses differ according to both exercise type and prandial state.

Study Overview

• Status: Completed
• Conditions: Diabetes Mellitus, Type 1
• Intervention / Treatment: Other: High-intensity interval exercise performed in postprandial phase; Other: High-intensity interval exercise performed in postabsorptive phase; Other: Moderate-intensity continuous exercise performed in postprandial phase; Other: Moderate-intensity continuous exercise performed in postabsorptive phase

Detailed Description

Participants were tested at the laboratory during one inclusion visit followed by 4 intervention visits separated by at least 48 hours and 4 weeks maximum. During the inclusion visit, participants completed the YMCA submaximal cycle-ergometer (Excalibur Sport, Lode B.V.) test to estimate maximal aerobic power (MAP), which was then used to determine subsequent exercise workloads. The test started at 25 W (50 rpm), with increasing power outputs derived from the first-stage heart-rate response. The 3-min stages continued until steady-state heart rate achieved 85% of maximal heart rate minus 10 bpm, with a 1-min extension if heart rate varied by >5 beats·min-¹ between minutes 2 and 3. Participants completed questionnaires about physical activity levels, barriers to physical activity, quality-of-life and hypoglycemia awareness. The next four experimental visits in randomized order consisted of the two aerobic exercises (i.e. high-intensity interval exercise, HIIE and moderate-intensity continuous exercise, CONT), each performed under two different prandial conditions, postprandial (PP) and postabsorptive (PA) state. A triaxial accelerometer (ActiGraph, wGT3X-BT, 30 Hz, epoch set at 60 sec) was worn on the hip from wake-up until bedtime for the day before, during and after each experimental visit. Participants were also asked to record the time, type and amount of food consumed, with the option of photographing meals, as well as in case of multiple daily injection doses/timing of insulin (rapid- and long-acting), the 24 hours before, during and after each visit. Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.) and were matched for total mechanical load and total duration. Both exercises began with a 3-min warm-up at 20% of MAP and ended with a 2-min active recovery at 20% of MAP. The HIIE protocol consisted of ten 1-min intervals at 100% of MAP, each interspersed with 1-min of passive recovery. The CONT protocol consisted of continuous exercise at 50% of MAP for 20 minutes. For the postprandial state, exercise began 1.5 hours after the start of lunch and the corresponding meal-related bolus/rapid-acting insulin, (i.e., in the early afternoon). For the postabsorptive state, exercise began 5 hours after the start of lunch, (i.e., in the late afternoon). Participants were instructed to follow their habitual pre-exercise routine and to replicate, as closely as possible, the same lunch and dinner on the days of the experimental visits. The measurements included: oxygen uptake, heart rate, rate of perceived exertion, muscle vasoreactivity during exercise; capillary glycaemia and lactataemia at several time points during exercise; continuous glucose monitoring data from the personal (used in daily life) device of the participants.

• Study Type: Interventional
• Enrollment (Actual): 21
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Loos, France, 59120
    • Unité de Recherche Pluridisciplinaire Sport, Santé, Société (URePSSS - ULR 7369)

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Between 18 and 60 years of age
• Regular practice of physical activity (at least 2 training sessions/week for at least 3 months)
• Diagnosis of type 1 diabetes for >1 year
• No change in insulin delivery method (i.e., multiple daily injections [MDI], continuous subcutaneous insulin infusion [CSII] in open or closed loop) over the previous 3 months
• Use of a continuous glucose monitoring (CGM) device in daily life

Exclusion Criteria:

• Diabetes-related complications except for background retinopathy

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

4

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: A/B/C/D; A= High-intensity interval exercise in postabsorptive phase B= High-intensity interval exercise in postprandial phase C= Moderate-intensity continuous exercise in postabsorptive phase D= Moderate-intensity continuous exercise in postprandial phase	Other: High-intensity interval exercise performed in postprandial phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The high-intensity interval exercise protocol consisted of ten 1-min intervals at 100% of MAP, each interspersed with 1-min of passive recovery. For the postprandial state, exercise began 1.5 hours after the start of lunch and the corresponding meal-related bolus/rapid-acting insulin (i.e., in the early afternoon).; Other: High-intensity interval exercise performed in postabsorptive phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The high-intensity interval exercise protocol consisted of ten 1-min intervals at 100% of MAP, each interspersed with 1-min of passive recovery. For the postabsorptive state, exercise began 5 hours after the start of lunch (i.e., in the late afternoon).; Other: Moderate-intensity continuous exercise performed in postprandial phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The moderate-intensity continuous exercise protocol consisted of continuous exercise at 50% of MAP for 20 minutes. For the postprandial state, exercise began 1.5 hours after the start of lunch and the corresponding meal-related bolus/rapid-acting insulin (i.e., in the early afternoon).; Other: Moderate-intensity continuous exercise performed in postabsorptive phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of MAP and ended with a 2-min active recovery at 20% of maximum aerobic power (MAP). The CONT protocol consisted of continuous exercise at 50% of MAP for 20 minutes. For the postabsorptive state, exercise began 5 hours after the start of lunch (i.e., in the late afternoon).
Experimental: B/C/D/A; A= High-intensity interval exercise in postabsorptive phase B= High-intensity interval exercise in postprandial phase C= Moderate-intensity continuous exercise in postabsorptive phase D= Moderate-intensity continuous exercise in postprandial phase	Other: High-intensity interval exercise performed in postprandial phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The high-intensity interval exercise protocol consisted of ten 1-min intervals at 100% of MAP, each interspersed with 1-min of passive recovery. For the postprandial state, exercise began 1.5 hours after the start of lunch and the corresponding meal-related bolus/rapid-acting insulin (i.e., in the early afternoon).; Other: High-intensity interval exercise performed in postabsorptive phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The high-intensity interval exercise protocol consisted of ten 1-min intervals at 100% of MAP, each interspersed with 1-min of passive recovery. For the postabsorptive state, exercise began 5 hours after the start of lunch (i.e., in the late afternoon).; Other: Moderate-intensity continuous exercise performed in postprandial phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The moderate-intensity continuous exercise protocol consisted of continuous exercise at 50% of MAP for 20 minutes. For the postprandial state, exercise began 1.5 hours after the start of lunch and the corresponding meal-related bolus/rapid-acting insulin (i.e., in the early afternoon).; Other: Moderate-intensity continuous exercise performed in postabsorptive phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of MAP and ended with a 2-min active recovery at 20% of maximum aerobic power (MAP). The CONT protocol consisted of continuous exercise at 50% of MAP for 20 minutes. For the postabsorptive state, exercise began 5 hours after the start of lunch (i.e., in the late afternoon).
Experimental: C/D/A/B; A= High-intensity interval exercise in postabsorptive phase B= High-intensity interval exercise in postprandial phase C= Moderate-intensity continuous exercise in postabsorptive phase D= Moderate-intensity continuous exercise in postprandial phase	Other: High-intensity interval exercise performed in postprandial phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The high-intensity interval exercise protocol consisted of ten 1-min intervals at 100% of MAP, each interspersed with 1-min of passive recovery. For the postprandial state, exercise began 1.5 hours after the start of lunch and the corresponding meal-related bolus/rapid-acting insulin (i.e., in the early afternoon).; Other: High-intensity interval exercise performed in postabsorptive phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The high-intensity interval exercise protocol consisted of ten 1-min intervals at 100% of MAP, each interspersed with 1-min of passive recovery. For the postabsorptive state, exercise began 5 hours after the start of lunch (i.e., in the late afternoon).; Other: Moderate-intensity continuous exercise performed in postprandial phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The moderate-intensity continuous exercise protocol consisted of continuous exercise at 50% of MAP for 20 minutes. For the postprandial state, exercise began 1.5 hours after the start of lunch and the corresponding meal-related bolus/rapid-acting insulin (i.e., in the early afternoon).; Other: Moderate-intensity continuous exercise performed in postabsorptive phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of MAP and ended with a 2-min active recovery at 20% of maximum aerobic power (MAP). The CONT protocol consisted of continuous exercise at 50% of MAP for 20 minutes. For the postabsorptive state, exercise began 5 hours after the start of lunch (i.e., in the late afternoon).
Experimental: D/A/B/C; A= High-intensity interval exercise in postabsorptive phase B= High-intensity interval exercise in postprandial phase C= Moderate-intensity continuous exercise in postabsorptive phase D= Moderate-intensity continuous exercise in postprandial phase	Other: High-intensity interval exercise performed in postprandial phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The high-intensity interval exercise protocol consisted of ten 1-min intervals at 100% of MAP, each interspersed with 1-min of passive recovery. For the postprandial state, exercise began 1.5 hours after the start of lunch and the corresponding meal-related bolus/rapid-acting insulin (i.e., in the early afternoon).; Other: High-intensity interval exercise performed in postabsorptive phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The high-intensity interval exercise protocol consisted of ten 1-min intervals at 100% of MAP, each interspersed with 1-min of passive recovery. For the postabsorptive state, exercise began 5 hours after the start of lunch (i.e., in the late afternoon).; Other: Moderate-intensity continuous exercise performed in postprandial phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of maximum aerobic power (MAP) and ended with a 2-min active recovery at 20% of MAP. The moderate-intensity continuous exercise protocol consisted of continuous exercise at 50% of MAP for 20 minutes. For the postprandial state, exercise began 1.5 hours after the start of lunch and the corresponding meal-related bolus/rapid-acting insulin (i.e., in the early afternoon).; Other: Moderate-intensity continuous exercise performed in postabsorptive phase; Exercises were performed on a cycle ergometer (Excalibur Sport, Lode B.V.). Exercise began with a 3-min warm-up at 20% of MAP and ended with a 2-min active recovery at 20% of maximum aerobic power (MAP). The CONT protocol consisted of continuous exercise at 50% of MAP for 20 minutes. For the postabsorptive state, exercise began 5 hours after the start of lunch (i.e., in the late afternoon).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Capillary glycemia	Blood glucose meter	At rest before exercise, then at 10 and 20 min of exercise, at 2 min of active recovery post-exercise, and at 10 min of passive recovery post-exercise.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Interstitial glucose	Continuous Glucose Monitoring system used by the participant in daily life	The 24 hours before and the 24 hours after each visit
Capillary blood lactate	Measured using the Lactate Scout device.	At rest before exercise, then at 10 and 20 min of exercise, at 2 min of active recovery post-exercise, and at 10 min of passive recovery post-exercise.
Oxygen consumption	Measured with a mask and a Vynthus CPX, Vyaire Medical	During a 5-min rest before exercise, a 3-min warm-up, 20-min of exercise, a 2-min active recovery post-exercise, and a 10-min passive recovery post-exercise.
Rate of Perveived Exertion	Rate of Perveived Exertion from the Borg Scale (6 to 20 scale)	At rest before the exercise, and then at 5-min, 10-min, 15-min and 20-min of exercise, at 2-min active recovery post-exercise and at 5 and 10-min passive recovery post-exercise.
Variation of muscle blood volume.	Measured with Near infrared spectroscopy (Artinis, PortaLite)	During a 5-min rest before exercise, a 3-min warm-up, 20-min of exercise, a 2-min active recovery post-exercise, and a 5-min passive recovery post-exercise.
Heart rate	Measured with Polar V800.	During a 5-min rest before exercise, a 3-min warm-up, 20-min of exercise, a 2-min active recovery post-exercise, and a 10-min passive recovery post-exercise.
Perceived pleasure	Physical activity enjoyment scale (PACES) 18 items rated on a 7-point Likert scale.	At the end of 10-min passive recovery post-exercise.

Collaborators and Investigators

• Sponsor: Universite du Littoral Cote d'Opale

Study record dates

Study Major Dates

• Study Start (Actual): February 8, 2023
• Primary Completion (Actual): January 17, 2025
• Study Completion (Actual): May 9, 2025

Study Registration Dates

• First Submitted: December 28, 2025
• First Submitted That Met QC Criteria: January 15, 2026
• First Posted (Actual): January 26, 2026

Study Record Updates

• Last Update Posted (Actual): January 26, 2026
• Last Update Submitted That Met QC Criteria: January 15, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Keywords: Hypoglycemia; Exercise; Blood glucose
• Additional Relevant MeSH Terms: Endocrine System Diseases; Metabolic Diseases; Autoimmune Diseases; Immune System Diseases; Glucose Metabolism Disorders; Diabetes Mellitus; Behavior; Nutritional and Metabolic Diseases; Hypoglycemia; Diabetes Mellitus, Type 1; Motor Activity
• Other Study ID Numbers: IRB00012476-2023-08-02-225

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The investigators will share on http://recherche.data.gouv.fr all anonymized data presented in the publication of the results
• IPD Sharing Time Frame: From the acceptance date of publication
• IPD Sharing Access Criteria: Access on e-mail request to investigators

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No